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FEDERICO CORNI

Docente a contratto
Dipartimento Educazione e Scienze Umane

Pubblicazioni

2019 - How metaphor and narrative interact in stories of forces of nature [Capitolo/Saggio]
Fuchs, H. U.; Contini, Annamaria; Elisabeth, Dumont; Landini, Alessandra; Corni, Federico
abstract

In this chapter, we shall present an example of a story and its use, point out the metaphors it contains, and argue that its conceptual structure is the same as that of its formal counterparts in physics. In other words, we claim that all of us can learn some good physics from stories of forces of nature. Moreover, we use the opportunity to contribute to the theme of metaphor and narrative by tackling the question of how the two interact in such stories. We find that, in general, analysts of metaphor or narrative treat one or the other of these cognitive tools but not both at once. Narrative is not commonly a theme in conceptual metaphor theory, and metaphors are not the main concern for the narratologist. We shall discuss three perspectives regarding the question of how metaphor and narrative relate to each other. First, and this may be the most directly useful for education, stories of forces of nature lead us back to what Kieran Egan has called mythic culture and mythic understanding (Egan, 1988, 1997). The interaction of physical phenomena and a mythic mind presents us with an experience where metaphors and stories form a natural unity. Secondly, we describe how the question of the relation between metaphor and narrative has been taken up in in modern philosophy and cognitive science. Finally, we briefly sketch a model of perception at different scales that shows us how, in stories of forces of nature, metaphors give (formal) content to stories and a story informs us about the meaning of the metaphors it contains.

2019 - Narrative minds in the construction and use of theories of forces of nature— A model of experience at different scales. [Capitolo/Saggio]
Fuchs, Hans U.; Dumont, Elisabeth; Corni, Federico
abstract

If the body of formal theories known as physics were the result of imaginative rationality, we might be inclined to think of physics rather differently than is traditionally the case. We could then easily identify conceptual metaphoric structures and narrative forms and processes in our formal theories, and we would consider them constitutive of the scientific enterprise and not just superficially imposed linguistic phenomena. We shall argue here that continuum physics is precisely this: the result of human imagination and imaginative rationality. We shall present linguistic and methodological evidence that modern classical macroscopic physics is metaphoric, analogical, and narrative all the way to its conceptual core. We will then outline a model of experience (action/perception/ conception) at different temporal, spatial, and systemic scales—but all within the range of human mesoscale worlds—that explains how metaphoric and narrative processes create the concepts of modern continuum physics.

2019 - Visual and gestural metaphors for introducing energy to student teachers of primary school and kindergarten levels [Relazione in Atti di Convegno]
Corni, F.; Fuchs, H. U.; Landini, A.; Giliberti, E.
abstract

The linguistic expressions scientists and educators use for energy are in most cases expressions of the principal metaphor of substance, although energy is an imponderable concept. The substance metaphor is embodied and familiar to students, so we can rely on it as useful for helping them develop a productive framework for understanding energy. In this paper we will introduce a laboratory course for student teachers of primary school and kindergarten levels using visual and gestural metaphors for introducing energy,

2018 - A didactic proposal about Rutherford backscattering spectrometry with theoretic, experimental, simulation and application activities [Articolo su rivista]
Corni, Federico; Michelini, Marisa
abstract

Rutherford Backscattering Spectrometry is a nuclear analysis technique widely used for material science investigation. Despite the strict technical requirements to perform the data acquisition, the interpretation of a spectrum is at the reach of general physics students. The main phenomena occurring during a collision between helium ions - with energy of few MeV - and matter are: elastic nuclear collision, elastic scattering, and, in case of non-surface collision, ion stopping. The models to interpret these phenomena are of classical physics: material point elastic collision, unscreened Coulomb scattering, and inelastic energy loss of ions with electrons, respectively. We present the educational proposal for RBS, in the framework of the model of educational reconstruction, following a rationale that links basic physics concepts with quantities for spectra analysis. This contribution offers the opportunity to design didactic specific interventions suitable for undergraduate and secondary school students.

2018 - An industrial educational laboratory at Ducati Foundation: narrative approaches to mechanics based upon continuum physics [Articolo su rivista]
Corni, Federico; Fuchs, Hans U.; Savino, Giovanni
abstract

This is a description of the conceptual foundations used for designing a novel learning environment for mechanics implemented as an Industrial Educational Laboratory – called Fisica in Moto (FiM) – at the Ducati Foundation in Bologna. In this paper, we will describe the motivation for and design of the conceptual approach to mechanics used in the lab – as such, the paper is theoretical in nature. The goal of FiM is to provide an approach to the teaching of mechanics based upon imaginative structures found in continuum physics suitable to engineering and science. We show how continuum physics creates models of mechanical phenomena by using momentum and angular momentum as primitive quantities. We analyse this approach in terms of cognitive linguistic concepts such as conceptual metaphor and narrative framing of macroscopic physical phenomena. The model discussed here has been used in the didactical design of the actual lab and raises questions for an investigation of student learning of mechanics in a narrative setting.

2018 - Conceptual Metaphor in Physics Education: Roots of Analogy, Visual Metaphors, and a Primary Physics Course for Student Teachers [Relazione in Atti di Convegno]
Corni, Federico; Fuchs, Hans U.; Dumont, Elisabeth
abstract

We show in what sense macroscopic physical science is a product of figurative (imaginative) structures of the human mind. Conceptual structure in physics is perception based and schematic and uses metaphoric, analogical, and narrative forms to extend direct perception and conception to cases of less directly accessible phenomena. For instance, a theory of the dynamics of heat can be rendered in a form analogous to that of fluids or electricity. We show how tools using visual forms of metaphors employed in macroscopic physical science can be designed and applied, and we briefly outline one application of the principles discussed here: a novel course for kindergarten and primary school student teachers.

2018 - From Metaphor to Narrative in Macroscopic Physical Science [Relazione in Atti di Convegno]
Fuchs, Hans U.; Dumont, Elisabeth; Corni, Federico
abstract

In this contribution, we shall argue that forces of nature are understood not only meta-phorically but also, and maybe even to a larger extent, narratively. We can demonstrate that, in hindsight, metaphoric structures of our concept of force of nature exist, and we can sketch their forms, but it is highly unlikely that our understanding of forces is creat-ed in a bottom-up metaphoric process. It seems much more likely that the origin of the notion of force(s) of nature stems from direct experience that is transformed in stories we tell about water and wind, fire and ice, and all the other forces that appear in human experience of nature.

2018 - L'uso del Playing per la concettualizzazione dell'energia: didattica della narrazione, della mente e del corpo per una educazione scientifica embodied ed intersoggettiva [Capitolo/Saggio]
Landini, Alessandra; Corni, Federico
abstract

L’energia è un tema trasversale a numerosi ambiti disciplinari e culture e, per sua stessa natura, si presta, nel senso comune, a svariate interpretazioni, permeando moltissimi luoghi di scambio e ambiti d’uso. L’uso diversificato e frequente che si fa del termine, non ultimo nella vita quotidiana, può portare allo stratificarsi di convinzioni, conoscenze ingenue, esperienze a volte dicotomiche e spesso confusive, a seconda del campo d’indagine e del contesto comunicativo. Per chi si occupa di energia a fini didattici, come Driver e Millar affermano, l'energia è uno dei concetti chiave della scienza, ed è essenziale per affrontarla comprendere gli aspetti fisici, biologici, chimici e tecnologici del nostro mondo (Driver and Millar, 1986). Ci chiediamo quindi innanzitutto, approcciandoci ad essa come studiosi di didattica e di scienze, perché risulta importante affrontare precocemente il tema dell’energia.

2018 - Metafore visive per l’energia. Ergolandia, la valigia didattica per introdurre l’energia come tema verticale dalla Scuola dell’Infanzia alla Scuola Secondaria di primo grado. [Capitolo/Saggio]
Corni, Federico; Fuchs, Hans U.
abstract

La percezione dei processi naturali porta alla formazione della gestalt della forza. Questa gestalt è resa cosciente e accessibile alla mente umana con l’aiuto di metafore e storie. Le forze della natura (vento, acqua, fuoco, ghiaccio, cibo, suolo, moto…) ci appaiono – e sono concettualizzate – come agenti potenti. Questi agenti hanno dimensione e intensi-tà, e il loro potere può essere misurato in termini di energia. Sadi Carnot ha dimostrato che si può creare una scienza del calore usando le metafore di quantità di fluido, tensione, e potenza. Mostreremo come questo archetipo può essere generalizzato e come si possono costruire diagrammi di processo in termini di metafore visive. Descriveremo poi come questo paradigma è sviluppato didatticamente, per l’educazione scientifica degli alunni dalla scuola dell’infanzia alla secondaria di primo grado, nella Valigia Ergoladia del progetto Max’s Worlds di MultiLab.

2018 - The Role of Playing in the Representation of the Concept of Energy: a Lab Experience for Future Primary School Teachers [Capitolo/Saggio]
Landini, Alessandra; Giliberti, Enrico; Corni, Federico
abstract

Energy, particularly in introductory physics at primary school level, is of-ten taught in terms of list of different “forms of energy” and seldom as a uni-fying concept underlying many aspects of the world. However, the “sub-stance” ontology for energy seems to be particularly productive in develop-ing understanding of energy and energy transfers. From a methodological point of view, narratives and forms of “playing” are valuable and significant representations that allow learning scientific concepts. Through a physical experience, in the form of role play, we help to develop the concept of ener-gy flow/current and storage. In this contribution, we propose a laboratory activity in which future primary school teachers represent the process of energy exchange among energy carriers. The participants are required to study a simple toy, finding the energy carriers, and the role of each of them; additionally, they have to write a story, with as many characters as the ener-gy carriers, telling how they exchange energy in the parts of the toy. Energy conservation and heat production are perceivable in the act of exchanging confetti which represent energy. The role play helps the participants to vis-ualize the energy as a substance, even though it is imperceptible. The analy-sis of the students’ role plays and the information collected from question-naires give feedback about students’ conceptualization of some of the most significant aspects of energy.

2018 - Transmission electron microscopy study of helium implanted silicon [Capitolo/Saggio]
Frabboni, Stefano; Corni, Federico; Tonini, Rita; Nobili, Carlo Emanuele; Ottaviani, Giampiero
abstract

The structural evolution of helium-related extended defects in silicon, formed after intermediate dose helium implantation and annealing, has been investigated. It is found that the highest helium concentration (annealing at 300°C) is associated with clusters of bubbles arranged in a platelet-like morphology. At 500°c the helium concentration markedly decreases and clusters of cavities formed by a central, large cavity surrounded by small cavities (planetarylike structures) are detected. Thermal treatment at 900°c accomplishes complete helium effusion from the sample leaving behind empty cavities i.e. voids.

2017 - Metafora e narrazione nella didattica delle scienze: nuovi strumenti e prospettive per l'educazione scientifica e la crescita professionale del docente. [Capitolo/Saggio]
Landini, Alessandra; Corni, Federico
abstract

Il progetto “Piccoli scienziati in laboratorio” nasce inizialmente rifacendosi alle Indicazioni Nazionali per il Curricolo della Scuola dell’Infanzia e del Primo Ciclo del 2007 arricchendosi poi con l’apporto delle più attuali Linee Guida del 2012. Nel corso degli ultimi anni il progetto si è evoluto in un Approccio didattico alle scienze, di tipo narrativo-metaforico che ha coinvolto numerosi soggetti in un’ottica di ricerca in sinergia col territorio. Due forti filoni nutrono il progetto “Piccoli scienziati in laboratorio”. Il primo è che parlare di scienza non significhi, nei bambini, ma non solo, parlare una lingua diversa dalla lingua naturale. Dai racconti mitici sui fenomeni naturali ai modelli più astratti, l’uomo “narra” la natura e i suoi eventi, permettendo una migliore “interpretazione” delle forze della natura. Le spiegazioni ingenue dei bambini stessi sono un inizio di concettualizzazione scientifica, un primo approccio ai perché e ai come del mondo che ci circonda. Si prefigura perciò un’educazione scientifica che favorisce le procedure argomentative, ma ne accetta il carattere finito, le riconosce utili in vista di scopi determinati. Questo pone l’insegnante stesso in una condizione di ricerca e di dialogo paradigmatici, dove anche le proposte dei bambini concorrono ad interpretare la realtà, anche i loro modelli si prefigurano come mondi possibili. Lo stesso Bruner d’altronde parte dall’assunto che gli esseri umani danno senso al mondo reale raccontando storie e critica il fatto che solo la modalità di spiegazione scientifica sia ammessa nelle lezioni di scienze (Bruner, 1996). Una chiave di svolta sulla strada di una migliore comprensione scientifica, nel quadro del conceptual change, sembrerebbe essere proprio l’uso di entrambi i pensieri, quello narrativo e quello paradigmatico, per permettere agli educatori di creare una sensibilità metacognitiva, necessaria per affrontare il mondo con la sua realtà narrata e le sue esigenze complesse. Questa apertura delle scienze alla razionalità immaginativa dei bambini prefigura un nuovo rapporto con la lingua, secondo filone che sostiene il progetto. In questo approccio per la comprensione scientifica gli oggetti concreti della lingua di tutti i giorni richiamano strutture schematiche (metafore, agenti e story schema) che sono a loro volta un meccanismo di proiezione di strutture gestaltiche di base (Image schema di contenitore, di verticalità, di percorso…). Queste sono il risultato delle nostre esperienze senso-motorie e percettive. La nostra lingua naturale è fisiologicamente intrisa di tali strutture, che sono incarnate nel nostro pensiero, perché fortemente embodied. Le storie artefatto che proponiamo, così come tutte le nostre spiegazioni dei fenomeni in cui siamo immersi, sono costruite con la lingua naturale e trasportano nei percorsi di comprensione immagini vivide e sensibili di tali strutture, favorendo il sorgere di concatenamenti analogici e metaforici. Tale contesto narrativo permette inoltre di lavorare creativamente sul come si costruisce una storia per le scienze: in accordo con un recente articolo di Fuchs, è necessario distinguere tra cosa è una storia e cosa è uno storyworld. Mentre le storie sono narrazioni concrete, gli storyworlds sono i modelli mentali che noi costruiamo quando siamo esposti alle storie. Saper ricostruire o creare una storia significa comprendere il cosa degli eventi, mentre lo storyworld sarà il framework che ci dà indicazioni sul perché degli eventi. Ed essendo gli agenti della storia coinvolti emotivamente e fisicamente nell’evento, creano per gli alunni una sorta di rispecchiamento nella realtà di tutti i giorni: per questo e per quanto detto sopra possiamo riferirci alla storia come a una simulazione e allo storyworld come a un modello simulato. La lingua, e le strutture semantiche e concettuali di cui sono riflesso e

2016 - Dalla narrazione all’esperienza in laboratorio: giochiamo e ragioniamo sull’Energia [Relazione in Atti di Convegno]
Landini, Alessandra; Corni, Federico
abstract

The present work explores the role of stories in science education and how it can be related to laboratorial experiences. An example in a laboratory about Energy aims to illustrate the value and significance of forms of playing during the scientific experience. The laboratory deals with active learning and hence the didactic utility of narratives: we would promote emotions use, as a bridge between our experiences and an embodied experience of natural phenomenon.

2015 - From naive to scientific understanding of motion and its causes [Relazione in Atti di Convegno]
Ascari, Alessandro; Corni, Federico; Ceroni, Gabriele; Fuchs, Hans U.
abstract

The difference in the descriptions of motion phenomena made by pupils in the first grades of secondary school and physicists is quite evident. Conceptual metaphors hidden in language suggest that there is continuity between the conceptual structure involved in the description and the interpretation of motion of experts and laypersons. In this paper the presence of such a continuity is shown through a metaphor analysis of linguistic expressions from both kind of people.

2015 - From naive to scientific understanding of motion and its causes [Articolo su rivista]
Ascari, Alessandro; Corni, Federico; Ceroni, Gabriele; Fuchs, Hans U.
abstract

2015 - Il progetto "Piccoli Scienziati": un approccio narrativo alle scienze per insegnanti in servizio [Relazione in Atti di Convegno]
Corni, Federico; Giliberti, Enrico; Altiero, Tiziana
abstract

Questo articolo presenta i principali riferimenti teorici alla base del progetto, per poi approfondire gli aspetti metodologici e didattici, con particolare riferimento alla narrazione e alla struttura verticale del curricolo proposto; seguono esempi di attività tratte da un segmento del percorso e infine viene illustrata la modalità di formazione degli insegnanti, così come è stata messa a punto negli anni si sperimentazione del progetto.

2015 - Innovazione nella didattica delle scienze nella scuola primaria e dell’infanzia: al crocevia fra discipline scientifiche e umanistiche. Atti del Convegno (Modena-Reggio Emilia, 21-22 novembre 2014). Articoli selezionati [Curatela]
Corni, Federico; Altiero, Tiziana
abstract

Il convegno “Innovazione nella didattica delle scienze nella scuola primaria e dell’infanzia: al crocevia fra discipline scientifiche e umanistiche” è giunto alla sua quarta edizione, nel 2016, come occasione di proficuo confronto all’insegna della continuità tra le discipline di area umanistica e quelle di area scientifica e tra ricercatori ed insegnanti. Il tradizionale divario tra mondo accademico e mondo della scuola viene infatti in questo appuntamento messo in discussione: lo scambio di ricerche, pratiche didattiche e considerazioni trovano nel convegno sulla didattica delle scienze il luogo deputato al dialogo interdisciplinare e al confronto costruttivo. Il convegno anche quest’anno ha confermato il forte carattere multidisciplinare e ha portato all’attenzione del pubblico testimonianze e ricerche dal forte carattere interdisciplinare: le scienze naturali e le scienze umanistiche hanno cercato finalità, strumenti e metodologie condivisibili: mentre la terza edizione del convegno tenutasi nel 2014 ha voluto esplorare ed approfondire le storie e la narrazione come strumento di costruzione di significati e di stimolo allo sviluppo del pensiero formale a partire dal linguaggio naturale, il convegno del 2016 focalizza la sua attenzione sulla metafora e sul suo rapporto con la narrazione per l’educazione scientifica. Anche quest’anno il convegno è strutturato in tre sessioni. Nella prima sessione (2 dicembre 2016) e seconda (3 dicembre 2016, mattina), studiosi riconosciuti a livello internazionale, esperti in diversi settori della ricerca, da quella umanistica a quella scientifica, presentano aspetti teorici frutto di recenti studi riguardanti le scienze cognitive, linguistiche e pedagogiche che si rivelano sempre più fondamentali per la didattica delle scienze nella scuola primaria e dell’infanzia. Sono affrontati temi e problematiche riguardanti anche la didattica delle scienze e la formazione insegnanti, presentando sperimentazioni metodologiche di percorsi scientifici realizzati nelle scuole. La terza sessione (3 dicembre 2016, pomeriggio), come di consueto, è dedicata alle presentazioni e alla discussione di contributi riguardanti le esperienze di pratica didattica e di ricerca inerenti al tema del convegno da parte dei numerosi insegnanti in servizio e in formazione e dei ricercatori provenienti da diverse regioni italiane e da altri stati europei. Questo volume riporta contributi selezionati tra quelli presentati al convegno. La lingua è quella originale dell'autore per preservare l'autenticità e la fedeltà del contenuto.

2014 - Dynamic Modeling with "MLE-Energy Dynamic" for Primary School [Relazione in Atti di Convegno]
Giliberti, Enrico; Corni, Federico
abstract

During the recent years simulation and modelling are growing instances in science education. In primary school, however, the main use of software is the simulation, due to the lack of modelling software tools specially designed to fit/accomplish the needs of primary education. In particular primary school teachers need to use simulation in a framework that is both consistent and simple enough to be understandable by children (Corni et al., 2010). One of the possible area to approach modelling is about the construction of the concept of energy, in particular for what concerns the relations among substance, potential, power (Fuchs, 2007). Following the previous initial research results with this approach (Corni et al., 2010), and with the static version of the software MLE Energy (Corni et al., 2009), we suggest the design and the experimentation of a dynamic modelling software - MLE dynamic - capable to represent dynamically the relations occurring when two substance-like quantities exchange energy, modifying their potential. By means of this software the user can graphically choose the dependent and independent variables and leave the other parameters fixed. The software has been initially evaluated, during a course of science education with a group of primary school teachers-to-be, to test the ability of the software to improve teachers’ way of thinking in terms of substance-like quantities and their effects (graphical representation of the extensive, intensive variables and their mutual relations); moreover, the software has been tested with a group of primary school teachers, asking their opinion about the software didactical relevance in the class work.

2014 - Dynamic modelling with “MLE-energy dynamic” for primary school [Relazione in Atti di Convegno]
Giliberti, E.; Corni, F.
abstract

During the recent years simulation and modelling are growing instances in science education. In primary school, however, the main use of software is the simulation, due to the lack of modelling software tools specially designed to fit/accomplish the needs of primary education. In particular primary school teachers need to use simulation in a framework that is both consistent and simple enough to be understandable by children [2]. One of the possible area to approach modelling is about the construction of the concept of energy, in particular for what concerns the relations among substance, potential, power [3]. Following the previous initial research results with this approach [2], and with the static version of the software MLE Energy [1], we suggest the design and the experimentation of a dynamic modelling software— MLE dynamic-capable to represent dynamically the relations occurring when two substance-like quantities exchange energy, modifying their potential. By means of this software the user can graphically choose the dependent and independent variables and leave the other parameters fixed. The software has been initially evaluated, during a course of science education with a group of primary school teachers-tobe, to test the ability of the software to improve teachers’ way of thinking in terms of substance-like quantities and their effects (graphical representation of the extensive, intensive variables and their mutual relations); moreover, the software has been tested with a group of primary school teachers, asking their opinion about the software didactical relevance in the class work.

2014 - Guided Participatory Research on Parallel Computer Architectures for K-12 Students Through a Narrative Approach [Relazione in Atti di Convegno]
Mazzoni, Valentina; Mortari, Luigina; Corni, Federico; Bertozzi, Davide
abstract

The approach to computer science (CS) education is typically geared towards the knowledge of the principles behind information technology, but there are social indicators that it overlooks some important educative aspects such as thinking competences and social attitudes. Such aspects play a fundamental role when bringing CS education to the K-12 level. In order to enable a truly educational experience, we propose to bring specific CS research problems within reach of K-12 students, because the active knowledge construction process that takes place during research requires children to be engaged with all of their knowledge, skills and attitudes. This poses the challenge of overcoming the knowledge gap of students, which we address by means of a synergistic cooperation of CS experts and educators. More specifically, we propose the narrative approach as the key enabler for CS participatory research with K-12 students.

2014 - Innovazione nella didattica delle scienze nella scuola primaria e dell'infanzia: al crocevia fra discipline scientifiche e umanistiche. Atti del convegno 2012 - Articoli selezionati. [Curatela]
Corni, Federico; Altiero, Tiziana
abstract

La seconda edizione del convegno “Innovazione nella didattica delle scienze nella scuola primaria e dell’infanzia: al crocevia fra discipline scientifiche e umanistiche” che, nella sua prima edizione del 2010, nasceva in risposta all’esigenza di dialogo tra mondo della scuola e della ricerca didattica e tra discipline scientifiche e discipline umanistiche, si è realizzata nel 2012 per continuare a tenere vivo questo dialogo aprendosi anche alla scuola dell’infanzia. Il convegno è stato organizzato in tre sessioni. Nella prima sessione (30 novembre 2012), i relatori invitati hanno sviluppato e approfondito ulteriormente i temi aperti nella precedente edizione del 2010. Sono stati quindi presentati aspetti teorici frutto di recenti studi riguardanti le scienze cognitive, linguistiche e pedagogiche che si rivelano sempre più fondamentali per la didattica delle scienze nella scuola primaria e dell’infanzia. Nella seconda sessione (1 dicembre 2012, mattina), i relatori invitati hanno affrontato temi e problematiche riguardanti la formazione insegnanti, presentando sperimentazioni metodologiche di percorsi scientifici realizzati nelle scuole. Successivamente, una prima tavola rotonda intitolata “Le scienze per un curricolo verticale e interdisciplinare” ha consentito ai relatori invitati e a tutti i partecipanti di confrontarsi sulle tematiche presentate. La terza sessione (1 dicembre 2012, pomeriggio) è stata dedicata alle presentazioni delle esperienze di pratica didattica e dei dati di ricerca inerenti al tema del convegno dei numerosi insegnanti in servizio e in formazione e dei ricercatori provenienti da diverse regioni italiane e da altri stati europei. Le relazioni presentate hanno affrontato argomenti riconducibili a quattro tematiche principali: narrazione, infanzia, linguaggio e concetti elementari. Il convegno si è concluso con una tavola rotonda intitolata “Prospettive per un insegnamento interdisciplinare” presieduta dal Direttore del Dipartimento di Educazione e Scienze Umane dell’Università di Modena e Reggio Emilia, alla quale hanno partecipato anche ricercatori e docenti dello stesso Dipartimento che si sono confrontati sui temi del convegno.

2014 - La storia di Margherita: per un’educazione scientifica nella scuola dell’infanzia e primaria [Relazione in Atti di Convegno]
Alessandra, Landini; Giliberti, Enrico; Corni, Federico
abstract

Partendo dagli ultimi studi riguardanti l’educazione scientifica dei bambini, che mostrano come sia possibile l’utilizzo di storie e narrazioni per favorire nell’infanzia la formazione dei concetti basilari per comprendere la scienza e la realtà che li circonda, il nostro progetto parte da due assunti. Il primo è che alla base del ragionamento scientifico si ipotizzano alcuni tools cognitivi che permettono di modellizzare, formulare ipotesi, svolgere esperimenti, formulare domande rilevanti (Fuchs, 2009). Il secondo è che la narrazione, promuovendo il coinvolgimento emotivo, cognitivo e immaginativo dei bambini (Egan, 1989, Bruner,1994), permette loro di fare esperienza e creare significato, applicando le stesse figure di pensiero ad aspetti della vita di tutti i giorni, così come a esperienze scientifiche riguardanti la loro vita. Il nostro progetto si è articolato, alla ricerca delle differenze e delle similitudini che potevano contraddistinguere questo approccio in diverse età evolutive infantili, in due sezioni: il primo rivolto alla terza sezione di scuola materna- prima classe primaria (5-6 anni), il secondo al primo ciclo di scuola primaria (7-8 anni). Nella distinzione si è cercato di prestare attenzione alla diversa impostazione pedagogica ed esperienziale dei due ordini scolastici, ma anche all’importanza degli anni-ponte come punto-chiave di raccordo psico-emotivo e metodologico che favorisca la continuità educativa e la crescita armonica del bambino. La storia, insieme alle semplici esperienze sperimentali proposte, mira a sviluppare la comprensione linguistica dei bambini e a implementare la loro capacità di descrizione verbale delle loro azioni in un contesto di esperienza scientifica e reale, dando significato più profondo alla natura e affiancando alle loro conoscenze pregresse nuovi e più rilevanti concetti scientifici.

2014 - Primary School Teachers: Becoming Aware of the Relevance of their own Scientific Knowledge [Relazione in Atti di Convegno]
Corni, Federico; Hans U., Fuchs; Giliberti, Enrico; Mariani, Cristina
abstract

We present details of a physics course for prospective primary school teachers that is based upon the structures of figurative thought available already to young children. The structures referred to are those found in the Force Dynamic Gestalt of natural forces such as heat, water, wind, electricity, chemicals, or motion. The same structures figure prominently in the formal science of physics. We demonstrate how student teachers can profit greatly from an approach that builds on everyday language and everyday conceptualizations. Our experience shows that teachers trained in this manner become confident narrators of basic physical processes.

2014 - Quantity/potential-related elementary concepts in primary school teacher education [Relazione in Atti di Convegno]
Corni, Federico; Giliberti, Enrico; Mariani, Cristina
abstract

Primary school teachers need a training in physics robust enough to enable them to understand phenomena and new and complex situations they encounter as well as to answer the children questions and to design teaching activities. In initial teacher education, it must also be taken into account the limited scientific and mathematical background of students enrolling in university courses. Starting from an analysis of the misconception to construct a formal knowledge that teachers need to make then non-formal to teach children, is ineffective. One more appropriate way seems to be based on research in the fields of cognitive sciences that focuses on the simple structure of imagination that are used to interpret everyday phenomena. The contents of the Physics course of the Degree in Primary Education of the University of Modena and Reggio Emilia have been structured in or¬der to highlight the common conceptual structures, and the specific differences, between the various contexts of the discipline. The elementary concepts such as quantity, storage, capacity, potential, current and resistance have been clarified, differentiated and built qualitatively though rigorously through a series of examples taken from everyday experience and known contexts. Analogy was introduced in the study of fluids, electricity, motion and heat, as a result of the use of the same elementary concept to interpret phenomena and processes. In this contribution we present the structure and the contents of the course according to this approach, and the results of the analysis of the worksheets about motion filled by students.

2014 - Report of the Workshop in GIREP-EPEC Conference in Finland on Teaching and Learning the Energy Concept and Teacher Formation in Primary School [Relazione in Atti di Convegno]
Corni, Federico; Marisa, Michelini; Lorenzo, Santi
abstract

The ways students, ranging in age from primary school through university, learn about energy and how this concept can be taught, have been productive subjects of physics education research (Duit, 1984; Goldring & Osborne, 1994; Solomon, 1992). Many proposals about how to teach the subject have been influenced by this research. Several researchers presented findings at a Symposium at GIREP 2008 in Cyprus that have implications for teaching energy concept. One of the conclusions reached at the Symposium was that no clear consensus exists regarding the structure of a vertically integrated curriculum for teaching energy. At the GIREP 2010 conference, a Workshop organized by Paula R.L. Heron and Marisa Michelini (with the contribution of Bat-Sheva Eylon, Yaron Leavi and Alberto Stefanel) took place and was attended by 25 colleagues from 9 countries. Three different groups discussed the issue for primary, lower secondary, and secondary schools, respectively. As a result, it was decided to form a GIREP Thematic Group on ENERGY that was charged to continue work on the subject both through electronic dissemination and through activities at GIREP conferences. The GIREP 2011 workshop on energy has been focused in particular on the primary school level. It consisted in the presentation of the position paper following the Reims Workshop and of two contributions about the construction of the concept of energy in primary school and in a course of teacher formation. This paper, as part of the Symposium “Teaching and learning the concept of energy from early childhood school through university”, reports on the discussion during the 2011 workshop and presents the points recognized to be important and fundamental for the introduction of the concept of energy at primary school level.

2014 - Rotations from a New Perspective: Experiments, Modelling and Analogies Based on Angular Momentum as an Extensive Quantity [Relazione in Atti di Convegno]
Ascari, Alessandro; Corni, Federico; Tommaso, Corridoni; Michele, D'Anna; Giovanni, Savino
abstract

Concepts and mathematical instruments used in elementary mechanics are often perceived as abstract entities by students. We propose therefore an approach to the description of rotational mechanical processes based on a conceptualization of angular momentum grounded on image schemes and analogies from common everyday experience (Fuchs, 2007). In our approach angular momentum is described as a conserved extensive quantity, whose balance equation is either an instrument to foster clear mental images of rotational processes, or a solid base for algebraic development. Exploiting analogies, in this work we show how this way angular momentum can be stored in rotating bodies, how their moment of inertia represents their angular momentum capacities, and finally how a torque applied to a rotating body can be imagined as an angular momentum flow. We analyse from this point of view three experiments, using on-line data acquisition and dynamical modelling. The use of analogies allows indeed to develop dynamical models in a wide range of contexts, able to strengthen basic concepts and discuss phenomena in relation with the initial conditions and the parameter values.

2014 - Stories in Physics Education [Relazione in Atti di Convegno]
Corni, Federico
abstract

Narratives are at the basis of every effort of making sense of human experience. Stories are a particular type of narrative particularly suitable for children because they involve them affectively and cognitively. This contribution deals with the opportunity of using stories for physics education in primary school. It is introduced a disciplinary approach suitable to be shaped into stories, relying on cognitive linguistics results, as well as some elementary features of the stories are compared to the fundamental caracteristics of scientific inquiry. Hints are proposed for possible rese arch programs and some examples of stories, coherent with this program, are presented and discussed.

2014 - Student Teachers Writing Science Stories: a Case Study [Relazione in Atti di Convegno]
Corni, Federico; Giliberti, Enrico; Hans U., Fuchs
abstract

In the following, we will present a few case studies of stories for science education. These were prepared by student teachers at the end of an elective laboratory course (16 hours) that focused on stories and followed the mandatory Fundamental Physics and Laboratory course (50 hours) at the University of Modena and Reggio Emilia. Both courses are based upon structures of figurative thought used in everyday language that even young children make use of. The structures referred to are found in the Force Dynamic Gestalt of natural forces such as heat, water, wind, electricity, chemicals, or motion. Cognitive linguists have identified image schemas which can be projected metaphorically upon particular phenomena, which then generate abstract concepts. The same structures figure prominently in the formal science of physics, allowing us to apply the power of natural language and narrative forms of science to comprehending nature. In this paper, we will investigate the hypothesis that allowing student teachers to write science stories for primary school is analogous to physics students creating and executing experiments. Although the results of this study may be qualitative and limited to a few stories, they demonstrate that story writing is indeed a powerful tool for professional development. Moreover, they support the notion of the narrative character of science teaching and learning. They open new perspectives for science curricula for primary school and an interdisciplinary approach to learning science and language.

2014 - The Story Format and the Cycle of Meaning Construction for Physics Education in Primary Schools [Relazione in Atti di Convegno]
Mariani, Cristina; Corni, Federico
abstract

The story format may provide a stimulating environment, including tasks, questions or problems, giving space for scientific experimentation and group discussions guided by the teacher. In this contribution we present the main advantages of the story format for physics teaching and learning and the features that a story should have in order to implement what we call the “cycle of meaning construction”, which constitutes an attempt to integrate the attributes already accredited to the story format in science teaching with pedagogical, methodological and didactic approaches. Lastly, a story will be presented in brief as a possible example for primary school physics education.

2013 - Force Dynamic Gestalt, image schema e concetti scientifici [Capitolo/Saggio]
Corni, Federico
abstract

Questo capitolo risponde alla domanda: quali sono i punti di partenza, i fondamenti, i concetti primari che stanno all’origine del pensiero scientifico e che, al contempo, sono così elementari da essere alla portata dei bambini?

2013 - Il Progetto IDIFO4: insegnanti e studenti protagonisti della loro formazione [Articolo su rivista]
Marisa, Michelini; . ., .; Angelini, Leonardo; Corni, Federico; Pauletta Giovanni, . . .
abstract

Il progetto Innovazione Didattica in Fisica e Orientamento (IDIFO4) è proposto in attuazione a quanto previsto nelle linee guida del Piano PLS nazionale e vede la collaborazione a vario titolo e impegno di 21 Università degli Studi e dell'INFN, per azioni differenziate di innovazione didattica, laboratori di apprendimento scientifico, scuola estiva per talenti e formazione degli insegnanti.

2013 - Le scienze nella prima educazione - Un approccio narrativo a un curricolo interdisciplinare [Curatela]
Corni, Federico
abstract

Cosa sarebbe un bambino (e un adulto!) che, per coltivare il pensiero razionale e logico, perdesse o fosse indotto a perdere la capacità di usare la fantasia e l’immaginazione, di stupirsi di fronte alla bellezza e alla varietà del mondo, di andare oltre l’apparenza? L’approccio di questo libro considera immaginazione, narrazione e gioco, da un lato, e ragionamento, rigore, impegno, dall’altro, non come due mondi separati (il primo dei quali da superare per lasciare posto al secondo), ma come gli estremi di una polarità dell’unico mondo, quello del bambino che sta crescendo, con un continuo di sfumature e di passi, senza saltare o dimenticare alcun passaggio. Attraverso contributi di studiosi e ricercatori con varie formazioni, si disegna un quadro in cui, finalmente e forse per la prima volta in Italia, si integrano i risultati della riflessione e della ricerca delle discipline, scientifiche e umanistiche, a cui ci si può rivolgere per un’educazione scientifica adeguata ai bambini, rispettosa delle loro potenzialità e dei loro strumenti cognitivi, e allo stesso tempo rigorosa e basata sui fondamenti propri della scienza. Destinato agli insegnanti di scuola dell’infanzia e primaria, l’opera fornisce un punto di partenza utile per un curricolo scolastico interdisciplinare e verticale, coerente con le linee generali delle ultime Indicazioni nazionali per il curricolo della scuola dell’infanzia e del primo ciclo d’istruzione.

2012 - A didactic approach to and curricular perspectives of the construction of the energy concept in primary school [Relazione in Atti di Convegno]
Mariani, Cristina; Corni, Federico; H. U., Fuchs
abstract

We propose activities and materials of a didactic approach to be used for constructing the energy concept in grades 4-5. Our approach integrates disciplinary, methodological and didactic aspects. We construct the energy concept from the cause-effect relationship of physical interactions by focusing on the differences of potentials (fall and rise of potentials) of the extensive quantities involved (such as fluids or heat). Students are introduced to the idea of energy being the agent responsible for the coupling of two processes. They will learn how the fall of an extensive quantity through its potential difference (cause) leads to the build-up of a secondary potential difference through which a different extensive quantity is “pumped uphill” (effect). Raising the potential of a certain amount of an extensive quantity by a certain value is caused by a proportionate lowering of the potential of a certain amount of another extensive quantity. The coupling of two processes is achieved by a kind of balance between cause and effect. The concept of energy then arises from the identification of the “proportion” between two processes taking part in an interaction.

2012 - A didactic path for age 5-8 on the concept of extensive quantity using a story as cognitive tool [Relazione in Atti di Convegno]
Mariani, Cristina; Corni, Federico; Giliberti, Enrico
abstract

We present a didactical path for the introduction of the concept of extensive quantity using a story as medium. We assume that stories can be suitable for pupils aged 5-8 as emotional, cognitive and imaginative tools. Teachers can make use of stories as a methodological scaffold, useful to design and lead the activities. The story, together with the experimental activity, can foster children’s verbal production. Moreover we want to give teachers the ability to move from the level of the experimental activity and the pupil’s verbal description of their actions to the level of scientific meaning of the same words/actions. This can be achieved providing teachers with a series of examples of words and phrases that pupils may use, and have to be recognized as indicative of the relevant concept.

2012 - A qualitative look on children’s words in explanation of processes [Relazione in Atti di Convegno]
E., Laurenti; Mariani, Cristina; Corni, Federico
abstract

A didactic path, devoted to build the concept of energy for primary school pupils, has been experimented. Energy is proposed as the proportion between the products of the amounts of the involved extensive quantities multiplied by the changes of the corresponding potentials. This paper presents a qualitative investigation about the language initially used by pupils to describe and interpret the processes and its evolution during the development of the didactic path. The theoretical framework is the figurative and embodied thought. The adopted interpretative key for analysis is addressed to point out some recurring linguistic-cognitive categories, semantically related to the “force-power” of entities in an interaction. The work consists in the individuation of the presence/absence of these force-power elements, through an analysis of the pupils discourses. The analysis results converge into an interpretative framework, in form of the keywords the teacher may use to assess the learning progress of each student. The research question is: how it can be constructed an analysis grid of language using language categories crossed with a scale of energy concept growth, so that it can be used to show the pupils concept evolution?

2012 - Concetti elementari per l’educazione scientifica nella scuola primaria [Capitolo/Saggio]
Corni, Federico
abstract

Un fenomeno che entra nell’esperienza viene interpretato: ma con che strumenti concettuali interpretiamo la realtà? Per rimanere a livello elementare, questi strumenti sono quelle strutture primordiali e universali di cui sopra, sono quelle astrazioni che la nostra mente è capace di costruire decontestualizzando aspetti dell’esperienza elementare e corporea. In un certo senso comprendiamo solo quello che siamo già portati a comprendere, o, in altre parole, incontriamo la realtà cercando delle assonanze con queste strutture primordiali di cui siamo dotati. Quando si formino queste astrazioni e come vengano utilizzate non è l’oggetto di questa trattazione: per i nostri fini possiamo riferirci a quello che da vari autori viene chiamato proiezione metaforica di image schema. Il nostro punto di partenza dell’educazione scientifica alla portata dei bambini sta nel fatto che alcune di queste strutture primordiali universali sono alla base del pensiero scientifico e che, sviluppando e imparando a utilizzare correttamente tali strutture, il bambino muove i primi passi verso la conoscenza scientifica, scava e rafforza le fondamenta che saranno alla base del suo pensiero formale che si svilupperà di pari passo con la sua maturità e le sue competenze di linguaggio.

2012 - Extended abstract: A didactic path for age 5-8 on the concept of extensive quantityusing a story as a cognitive tool [Articolo su rivista]
Mariani, Cristina; Corni, Federico; Giliberti, Enrico
abstract

The main goal of this didactical path is to ensure that pupilsof ages 5–8 achieve a good mastery of the concepts ofextensive quantity. How can the concept of quantity beexplored starting from an early age? Which cognitive toolscan be supplied both to teacher and pupils to help them inrecognising and setting in the right place the emerging ideasrelated with this concept?From the teaching side, we suggest the use of a didacticalpath, which represents a methodological framework in whichchildren and teacher can work together.

2012 - Force dynamic gestalt of natural phenomena: teaching the concept of energy [Relazione in Atti di Convegno]
H. U., Fuchs; Corni, Federico; Giliberti, Enrico; Mariani, Cristina
abstract

Modern cognitive science in general and cognitive linguistics in particular teach us about basic figurative structures of the human mind which are used to conceptualize natural, psychological, and social phenomena and processes. These figures of thought are based on schematic structures that develop early in the life of a child. We have identified a structure, the Force Dynamic Gestalt, which underlies both everyday language and reasoning and the formal science of physics. If teachers learn to make use of these figurative structures, they are in a position to produce well-crafted narratives with which they can confidently teach other- wise complex and formal subjects. We demonstrate how to use the approach for developing the energy concept in primary school. The method lends itself well to a deliberate movement from the affective and qualitative to the logical and quantitative, and to the use of role games, stories, outdoor activities, laboratory work, drawings, writings etc. Linguistic and graphical tools will be described that make this approach not only simple but also natural.

2012 - Hands-on, minds-on activities to construct the concept of energy in primary school: Experiments, games and group discussions [Articolo su rivista]
Mariani, Cristina; Laurenti, E.; Corni, Federico
abstract

In this article we present hands-on and minds-on activities about teaching and learning the concept of energy in primary school.The concept of energy is constructed by starting from the cause-effect relationship and focusing on the differences of potentials (increases and decreases in potentials) of the extensive quantities involved in the process of interaction being analysed. Subsequently, in order to lay the foundations for the concept of conservation, students are guided by the teacher to grasp the relationship between potential differences and the associated extensive quantity currents to build a (qualitative) budget law (relationships of direct or inverse proportionality): some increase in potential (effect) of an amount of an extensive quantity, at the expense of some reduction in potential (cause) of another amount of extensive quantity. The energy concept, then, arises from the identification of the “proportion” between two processes taking part in an interaction.The activities we propose are guided by the teacher following a didactic cycle with a semiotic approach designed to overcome the fact that the child may remain unaware of the connection between the concrete experiment and its underlying scientific concepts. This cycle, that leads to the transition from the concrete experiential level to that of the decontextualization and building of scientific meanings, includes experimental activities and games, individual production of outputs (oral and written texts, drawings, sketches, gestures, gazes and sounds...) and group discussions. We will present the activities and the didactic materials experimented with in a 5th grade classroom as well as the linguistic criteria defined and used to analyse pupil worksheets and conversations. We will also share the results which highlight evidence how children express their thoughts using “signs” that the teacher can then use to create a link between the concrete experiential plane and the conceptual one.

2012 - Le scienze alla portata dei bambini [Curatela]
Corni, Federico
abstract

Questo saggio si pone a quel crocevia tra gli studi delle discipline scientifiche e quelli delle discipline umanistiche, dove emergono e si incontrano aspetti e temi di interesse per la scuola e per gli insegnanti. Un crocevia che può diventare punto di incontro tra il mondo accademico e della ricerca, spesso isolato e autoreferenziale, ma ricco di preziose idee e risultati di potenziale utilità pratica, ed il mondo della scuola, degli insegnanti, dei formatori, spesso chiuso o lontano dall'innovazione e dalla ricerca di nuovi spunti e metodologie. Questo non è un libro esaustivo sul tema dell'educazione scientifica. E’ ben lungi dall'esserlo e dal volerlo essere. Ha, però, una presunzione: quella di essere un inizio, un'introduzione a questo crocevia dove si può fare un lavoro nuovo, di cui si è sentito spesso l’esigenza, ma che fino ad ora non ha trovato le condizioni favorevoli per partire. Le domande a cui cercare di rispondere sono tante. Si può realmente fare scienza coi bambini? Come parlare di scienze in modo adeguato ai bambini? Il linguaggio da usare può avere un rigore simile a quello formale delle scienze? I discorsi che si possono fare con i bambini devono riguardare solo temi concreti o possono trattare anche temi astratti? Quali strumenti occorre considerare perché siano adeguati ai bambini e utili per loro in funzione della loro educazione? La propensione alla fantasia, alle storie fantastiche, all'immaginazione e al gioco possono sembrare un ostacolo al fare scienza in modo serio coi bambini. Questo approccio parte considerando immaginazione, narrazione, gioco da un lato, e ragionamento, rigore, impegno dall'altro non come due mondi separati (il primo dei quali da superare per lasciar posto al secondo), ma come gli estremi di una polarità dell'unico mondo, quello del bambino che sta crescendo, con un continuo di sfumature e di passi fra i due estremi in un'ottica di sviluppo armonico di tutte le facoltà fisiche, mentali e affettive.

2012 - Piccoli scienziati in laboratorio. Percorsi di formazione scientifica per insegnanti di scuola primaria. [Capitolo/Saggio]
Corni, Federico; Giliberti, Enrico; Mariani, Cristina
abstract

Il tema delle conoscenze in ambito scientifico degli insegnanti di scuola primaria è stato studiato con diverse modalità (Kruger et al., 1992; Greenwood 1996; Atwood et al. 2001) evidenziando che essi condividono le stesse misconcezioni degli alunni. La nostra assunzione è che alla base del ragionamento scientifico ci siano alcuni tools cognitivi che permettano di svolgere quattro distinte attività: modellizzazione, formulazione di ipotesi, svolgimento di esperimenti, formulazione di domande rilevanti (Fuchs, 2009). Inoltre la letteratura suggerisce l’utilizzo di storie e della narrazione per promuovere il coinvolgimento emotivo, cognitivo e immaginativo dei bambini.(Egan,1989). Utilizzare le storie assicura il coinvolgimento emotivo e cognitivo dei bambini (Bruner, 1994). Gli alunni, guidati dall’insegnante che propone domande guida per favorire la riflessione, assumono un ruolo attivo nella costruzione della conoscenza attraverso la formulazione e validazione di ipotesi tramite l’attività sperimentale. Per garantire l’acquisizione delle metodologie e degli elementi disciplinari necessari per allestire percorsi di educazione scientifica secondo il modello proposto occorre promuovere la formazione degli insegnanti in una modalità innovativa, che coniughi momenti di formazione rispetto a specifici contenuti disciplinari con momenti di sperimentazione in classe e confronto fra pari. Il progetto “Piccoli scienziati in laboratorio” propone una serie di percorsi formativi rivolti ad insegnanti di scuola primaria sui temi dell’energia, della quantità, del moto, dei fluidi e del loro movimento. Tali percorsi potranno essere proposti in classe con il supporto di materiali sperimentali, storie, cartoni animati, un software di modellizzazione. In questo contributo, oltre alle scelte metodologiche e ai principali nodi concettuali, saranno presentati i primi risultati della sperimentazione, che ha coinvolto circa 200 insegnanti in diverse regioni, con i dati derivanti dai primi corsi di formazione.

2012 - Semiotic Mediation in Mathematics and Physics Classrooms: Artefacts and Signs after a Vygotskian Approach [Articolo su rivista]
Bartolini, Maria Giuseppina; Corni, Federico; Mariani, Cristina; Falcade, Rossana
abstract

The theoretical framework of semiotic mediation after a Vygotskian approach, introduced first for mathematics education is extended to physics education. Beyond obvious epistemological differences between mathematics and physics, dialogue and relationship show fruitful, drawing on the Vygotskian perspective of obučenie. The aim of this paper is to show that the theoretical framework of semiotic mediation might offer methodological scaffolding for teachers in order to mediate scientific meanings that have been historically incorporated in artifacts and experimental methods. Cross-fertilization between the two research programs on mathematics and physics education at primary school level is discussed.

2012 - Semiotic mediation and didactical cycle as methodological reference for primary school teachers [Relazione in Atti di Convegno]
Corni, Federico; Giliberti, Enrico; Mariani, Cristina
abstract

The theoretical framework of semiotic mediation, after a Vygotskian approach within activity theory, fruitfully introduced for mathematics education, has been transposed and adapted to laboratory science education activities. Aim of this paper is to show how this framework can be used as a methodological reference for teachers to mediate scientific meanings. An example addressed to teachers of application to laboratory activities with a jet car toy is proposed.

2012 - Using evidence from nanocavities to assess the vibrational properties of external surfaces [Articolo su rivista]
G. F., Cerofolini; CORNI, Federico; FRABBONI, Stefano; OTTAVIANI, Giampiero; E., Romano; TONINI, Rita; D., Narducci
abstract

Internal surfaces of nanocavities are an exceptionally useful laboratory wherein one can spotlight the factors ruling the intricate interplay between morphology and chemistry at silicon surfaces. At the same time, they offer unparalleled opportunities to validate the assignment of vibrational signals of silicon-terminating species under almost ideal experimental conditions. In the case of hydrogen, evidence will be provided of the detailed evolution of H-related species at surfaces depending on their orientation. Also, preliminary results concerning nitrogen at and around nanocavity surfaces will be reported.

2011 - AN APPROACH TO THE CONCEPT OF ENERGY FOR PRIMARY SCHOOL: DISCIPLINARY FRAMEWORK, ELEMENTS OF A DIDACTIC PATH AND ASSESSMENT SCALE [Relazione in Atti di Convegno]
Corni, Federico
abstract

Hands-on and minds-on activities about teaching and learning the concept of energy in primary school will be presented.The word “energy”, even if already used by the children in everyday life, is not cited by the teacher during the lessons of the didactic path in order to build the underlying concept on scientific bases, unfolding all the basic aspects and avoiding misconceptions and misunderstandings. The concept of energy is constructed by starting from the cause-effect relationship and focusing on the differences of potentials (increases and decreases in potentials) of the extensive quantities involved in the process of interaction being analyzed. Subsequently, in order to lay the foundations for the concept of conservation, the relationship between potential differences and the associated extensive quantity currents is recognized, to build a (qualitative) budget law (relationships of direct or inverse proportionality): some increase in potential (effect) of an amount of an extensive quantity, at the expense of some reduction in potential (cause) of another amount of extensive quantity. The energy concept, then, arises from the identification of the “proportion” between two processes taking part in an interaction.The activities and the didactic materials experimented in a 5th grade classroom will be presented. Moreover, in order to evaluate the pupils’ progresses in the development of the concept of energy, linguistic criteria to analyze worksheets and conversations will be introduced together with some results which highlight evidence how children express their thoughts using “signs” that the teacher can then use to create a link between the concrete experiential plane and the conceptual one.

2011 - Extended Abstract: Semiotic mediation and the didactical cycle as a methodological reference for primary science teachers [Articolo su rivista]
Corni, Federico; Giliberti, Enrico; Mariani, Cristina
abstract

Primary school teachers have difficulties in teaching sciences and in particular in driving la-boratory activities, addressed to encourage early science thinking, to achieve a lasting effect of science education. Science laboratory activities risk to be reduced to a set of trivial practic-es, or mere manipulation, or twiddling, to be executed by children, without the suitable and precise teacher’s guidance, while, according to the Vygotskian perspective of obucenie (Mecacci,1990), the teacher’s active role is fundamental. In literature or in textbooks, a wide variety of educational school courses is documented, while effective methods on teaching /learning processes are not so widely available. In this contribution, after a synthetic presenta-tion of a proposal of a methodological framework, an example of semiotic approach to intro-duce children to energy meaning construction will be presented and discussed.

2011 - IL PROGETTO “PICCOLI SCIENZIATI”: METODO, CONTENUTI E STRUMENTI [Relazione in Atti di Convegno]
Corni, Federico; Giliberti, Enrico; Mariani, Cristina
abstract

Il progetto “Piccoli scienziati in laboratorio, storie, esperimenti e modelli per la formazione scientifica nella scuola primaria” è nato nel 2008 e in seguito ha avuto il cofinanziamento del Ministero dell’Istruzione, dell’Università e della Ricerca all’interno dei bando per la diffusione della cultura scientifica 2009 e del Dipartimento di Fisica dell’Università di Modena e Reggio Emilia con responsabile il prof. Federico Corni. Nel tempo il progetto si è sviluppato, attualmente è alla sua seconda edizione e sono in fase di svolgimento le sperimentazioni nelle classi nell’attuale anno scolastico 2010/2011.Il punto di forza del progetto consiste nella collaborazione di soggetti con diverse competenze chiave che hanno contribuito e contribuiscono al suo sviluppo.Intorno ai ricercatori dell’Università di Modena e Reggio Emilia (Federico Corni, fisico, Enrico Giliberti, pedagogista, e Cristina Mariani, biologa) che inizialmente lo hanno fondato, infatti, nel tempo si sono raccolti e hanno contribuito attivamente insegnanti sperimentatori (troppo numerosi per essere citati, ciascuno col suo contributo particolare), studenti, tirocinanti e laureandi del Corso di Laurea in Scienze della Formazione Primaria, l’artista illustratore per l’infanzia Arcadio Lobato, Pietro Pinetti con lo studio di animazione Bozzetto & Co, e, più recentemente, ma non da ultimi per importanza, ricercatori della Facoltà di Scienze della Formazione, sia scienziati che umanisti (veditavole rotonde), e il prof. Hans Fuchs dell’Università di Zurigo a Winterthur.È da questa ampia collaborazione che l’intuizione e l’intenzione iniziali, cioè di considerare il bambino nella sua globalità tenendo conto dei fattori che lo costituiscono e che lo influenzano, si sono potute esplicitare e concretizzare con metodi, contenuti e strumenti. In questo senso le discipline scientifiche e quelle umanistiche trovano un punto di convergenza nel collaborare alla didattica delle scienze per la scuola primaria.

2011 - Il Laboratorio didattico Fisica in Moto. La fisica in un contesto quotidiano: una collaborazione fra impresa, scuola e università [Articolo su rivista]
Corni, Federico; Savino, G.; Ricco, Antonio; Fronzi, Giovanna; Filipucci, M.
abstract

“Fisica in Moto” è un innovativo Laboratorio didattico di fisica dedicato agli studenti di scuola secondaria, creato da Fondazione Ducati all’interno degli stabilimenti dell’azienda motociclistica Ducati Motor Holding di Bologna. Nel Laboratorio, gli studenti in visita sono accompagnati da tutor didattici a scoprire i principi della meccanica attraverso exhibit di tipo hands-on ispirati dal mondo delle motociclette. La proposta didattica del Laboratorio è basata sui concetti di quantità di moto e momento angolare, presentati come quantità che attraverso l’interazione possono essere scambiate tra corpi, pur conservandosi globalmente per sistemi isolati.Il presente articolo descrive l’approccio alla fisica che è stato adottato per lo sviluppo del Laboratorio e il metodo d’insegnamento utilizzato per le visite guidate. Inoltre l’articolo presentata sinteticamente uno dei possibili percorsi didattici, quale esemplificazione delle attività che gli studenti svolgono all’interno del Laboratorio Fisica in Moto.

2011 - Il progetto “Piccoli scienziati ”: modellizzazione e collaborazione [Relazione in Atti di Convegno]
Giliberti, Enrico; Mariani, Cristina; Corni, Federico
abstract

La modellizzazione costituisce uno degli strumenti fondamentali per ladescrizione e la comprensione dei fenomeni che osserviamo quotidianamente. Il pensiero umano per molti suoi processi fa uso di modelli mentali, che costituiscono la base del ragionamento e del linguaggio. È quindi fondamentale utilizzare strategie e strumenti che favoriscano e rinforzino questa abilità e che permettano di esplicitare e rendere oggetto di discussione e confronto i modelli mentali. Un modo per costruire e rappresentare i modelli è costituito dai software di modellizzazione, fra i quali spiccano i software di modellizzazione dinamica, che permettono cioè esplorare le relazioni fra le variabili presenti nel modello.In questo contributo, dopo una breve trattazione dei temi della modellizzazione e della collaborazione, si presenta la proposta di utilizzo di un software, MLEEnergy, che consente di rappresentare in forma iconica, attraverso alcuni semplici simboli, i trasferimenti di energia. Tale software può essere utilizzato per facilitare un processo di modellizzazione già a partire dalla scuola primaria, permette di creare catene di energia a partire da fenomeni osservati, sperimentati o presentati a partire da suggestioni diverse come ad esempioriviste, libri di testo o filmati.Saranno analizzate alcune caratteristiche del software che ne permettono l’utilizzo in modo collaborativo fra alunni di una stessa classe o anche di classi diverse. Infine si suggeriranno alcuni percorsi collaborativi rivolti agli insegnanti che a diversi livelli sperimenteranno l’utilizzo del software in classe.

2011 - Il progetto “Piccoli scienziati ”: storie e percorsi [Relazione in Atti di Convegno]
Mariani, Cristina; Giliberti, Enrico; Corni, Federico
abstract

I percorsi didattici “Quantità e qualità”, “L’acqua e il suo movimento”, “Energia” sono accomunati da vari elementi, tra cui la presenza di una storia, intesa come sfondo integratore di attività e riflessioni connesse ad un esperimento, che concorre allo stimolo di capacità di tipo creativo-immaginativo e logicodeduttivo.L’esperimento, connesso alla situazione problematica della storia, è proposto con una serie di domande che aiutano ad evidenziarne aspettistrutturali, relazionali e funzionali, al fine di favorire la formulazione di ipotesi e di interpretazioni. Le proposte didattiche tengono presente il presupposto che l’acquisizione di conoscenze e competenze scientifiche sono favorite se il bambino è direttamente implicato nel processo di apprendimento sia dal punto di vista emotivo che cognitivo e che, per evitare fratture tra il sapere quotidiano e il sapere scientifico, quest’ultimo deve essere costruito dai modi di ragionare del bambino, che vanno guidati e fatti evolvere dall’azione didattica.Nel presente articolo presentiamo sia le caratteristiche delle storieche concorrono al raggiungimento delle finalità preposte, sia una sintesi della struttura dei tre percorsi.

2011 - Il progetto “Piccoli scienziati”: Idrolandia ed Ergolandia, le valigie di Pico [Relazione in Atti di Convegno]
Laurenti, Erica; Giliberti, Enrico; Mariani, Cristina; Corni, Federico
abstract

Durante il convegno sono state messe in esposizione le Valigie di Pico Idrolandia ed Ergolandia, che costituiscono la strumentazione gioco/artefatto per le sperimentazioni dei percorsi sull’acqua e sull’energia, proposte nell’anno scolastico 2010/2011 all’interno del progetto “Piccoli scienziati in laboratorio” ed in corso di sperimentazione in alcune scuole delle province di Modena, Reggio Emilia e Trento.Le idee che stanno alla base di questo approccio spiegano la struttura dei percorsi e la scelta del materiale, che ha lo scopo di promuovere una didattica delle scienze che si avvicini al modo di ragionare metaforico del bambino.Il percorso si propone di realizzare questo obiettivo agendo sia sul contesto di apprendimento delle scienze, sia sui contenuti-concetti che costituiscono gli obiettivi di apprendimento.

2011 - Innovazione nella didattica delle scienze nella scuola primaria: al crocevia fra discipline scientifiche e umanistiche [Articolo su rivista]
Corni, Federico
abstract

Si apre a partire dal prossimo numero la rubrica La Fisica per la Scuola dell’Obbligo. Non è una novità per la nostra rivista. Certo è che l’insegnamento/apprendimento della Fisica fin dalla scuola primaria è sempre più in primo piano: basti pensare all’attenzione crescente che si riserva alle indagini internazionali (IEA-TIMSS e OCSE-PISA in primo luogo) e ai risultati dei nostri studenti. Ancor più importante è l’ottica di verticalità in cui oggi vengono costruiti (o è auspicato che lo siano) i curricoli scolastici.Insomma questo spazio ci sembra un’esigenza sentita e condivisa dal mondo della scuola.Si apre questa rubrica con un contributo che eccezionalmente non è nella forma di proposta o di esperienza didattica, ma di riflessione e contemporaneamente di lancio di temi “caldi” e trasversali per i futuri contributi per una fascia di età così ampia e complessa. Si tratta di un articolo riguardo a un convegno sull’innovazione nell’insegnamento delle scienze nella scuola primaria tenutosi il 12 e 13 novembre 2010 presso l’Università di Modena e Reggio Emilia.

2011 - Innovazione nella didattica delle scienze nella scuola primaria: al crocevia fra discipline scientifiche e umanistiche.Seminari, aperture, contributi di ricerca, esperienze di pratica didattica. [Curatela]
Corni, Federico; Mariani, Cristina; Laurenti, Erica
abstract

Il convegno “Innovazione nella didattica delle scienze nella scuola primaria: al crocevia fra discipline scientifiche e umanistiche” è nato in risposta all’esigenza di dialogo tra mondo della scuola e della ricerca didattica e tra discipline scientifiche e discipline umanistiche.Il convegno è stato organizzato in tre sessioni. Nella prima sessione (12 Novembre 2010), i relatori invitati hanno introdotto argomenti dal punto di vista disciplinare e didattico per la scuola primaria e secondaria di primo grado, evidenziando punti di fondo delle scienze e possibili intersezioni con il linguaggio, la genesi e la strutturazione dei significati. La seconda sessione (13 Novembre 2010 mattina) è stata dedicata alle esperienze di pratica didattica. È stato presentato il progetto “Piccoli scienziati in laboratorio” dell’Università di Modena e Reggio Emilia e successivamente, numerosi insegnanti e ricercatori provenienti da diverse regioni italiane, hanno esposto relazioni e dati di ricerca inerenti al tema del convegno.Dopo i commenti dei discussant, nella sessione finale (13 Novembre 2010 pomeriggio), i docenti e i ricercatori della Facoltà di Scienze della Formazione dell’Università di Modena e Reggio Emilia si sono confrontati in due tavole rotonde su “Linguaggi e storie” e “Insegnamento e apprendimento”.Questo volume raccoglie i testi dei contributi delle tre sessioni del convegno.

2011 - MASTER IDIFO (INNOVAZIONE DIDATTICA IN FISICA E ORIENTAMENTO): A COMMUNITY OF ITALIAN PHYSICS EDUCATION RESEARCHERS AND TEACHERS AS A MODEL FOR A RESEARCH BASED IN-SERVICE TEACHER DEVELOPMENT IN MODERN PHYSICS. [Relazione in Atti di Convegno]
R., Battaglia; L., Cazzaniga; Corni, Federico; A., De Ambrosis; C., Fazio; M., Giliberti; O., Levrini; M., Michelini; A., Mossenta; L., Santi; R. M., Sperandeo; A., Stefanel
abstract

The technique for material analysis Rutherford Backscattering Spectrometry (RBS) has been object of a distance course for the IDIFO Master in Modern Physics. After the introduction of the basic physical models for the interpretation of the phenomena occurring when a light and energetic ion beam impinges on the surface of a solid sample, students were invited to discuss, through network forums, the various models from the disciplinary point of view as well as in the view of a possible didactical path. The second part of the course was devoted to the interpretation of elementary RBS spectra, during which students were invited to complete with their comments and interpretations a table containing some simulated RBS spectra of thin heavy elements films over light substrates. Finally students had to design a didactical path for secondary school students on the basis of the course contents. This contribution for the IDIFO workshop presents the structure of the course and analyzes the contents of the discussion forums.

2011 - PAINT AND ART: A PROPOSAL OF PHYSICS IN CONTEXT IN A TEACHER TRAINING MASTER [Articolo su rivista]
Corni, Federico; M., Michelini; L., Santi; A., Stefanel
abstract

Teaching Physics in context is one of the key to open new way of learning for the pupils. It give the opportunity to understand how physics constructs link between theory and real world and to make explicit the cultural value of physics for all citizen and not only for scientist. In particular art is a very stimulating field in which we can build physics knowledge, evidencing at the same time the interlacing between art techniques and physics laws, useful for understanding everyday phenomena, connected with other field of knowledge. We developed a proposal in which the painting properties and the related optical perceptions stimulate questions, that motivate the search of physical law at the base of observed phenomena. In the context of IDIFO Master instituted as an application of National Plan for Scientific Degree (PLS) for physics teachers we carried out a Module of Formative Intervention on this topic enriched by a discussion in web forum about physics and painting art. One of the main results for teachers participating was the adoption of new ways for teaching physic and the relative connection with math culture. Considering in particular the final documents produced, summarizing the proposal of school activities, emerged three different positions: who suggest effective context in which motivate the study of physical law; who separate completely the physics treatment from the successive analysis of painting; who interpret the opportunity to link physics and art to include humanistic aspect in physics lessons.

2011 - RUTHERFORD BACKSCATTERING SPECTROMETRY: A LABORATORY DIDACTIC PATH ABOUT THE BASIC INTERPRETATION MODELS [Relazione in Atti di Convegno]
Corni, Federico
abstract

Each time a new physical phenomenon is understood in depth, new techniques of analysis are produced, which employ the fresh knowledge to start new researches in unexplored field. Most of the techniques for material science are based on quantum mechanics, since matter is studied in terms of interactions with its microscopic components (e.g. atoms, nucleuses and electrons) or aggregates of them (e.g. molecules, crystals, phonons). However, due to the strong orientation of the techniques to gain qualitative or quantitative information (doing measurements), they are often interpreted according to semi-classical or classical models (e.g. the effective mass for conduction of a charged particle, the electron gas in a metal, the phonon as a harmonic oscillator etc.). In this sense, the analysis techniques can be introduced in physics education as a bridge between classical physics and quantum mechanics with its applications. Moreover, these techniques offer an opportunity to introduce stimulating topics of modern physics which in most cases constitute also a synthesis of various topics traditionally taught in separate contexts (mechanics, thermodynamics, electromagnetism etc).Rutheford Backscattering Spectrometry (RBS) is an analysis technique largely used in material science [1] and it constitutes a candidate technique for secondary school level students. It can be entirely understood and interpreted in terms of classical models and the teacher is free to deal with each concept also in terms of quantum mechanics. Moreover RBS can be an exciting subject for students since they can feel the experience, as in the research field, of interpreting a spectrum and obtaining structural and elemental information about an actual sample applying physical concepts and models.The didactic proposal that will be presented follows previous experience and research works about the introduction of the analysis techniques into the curriculum of secondary school [2-8] and benefits from a direct involvement in the use of RBS for condensed matter analyses. The aim of the activity is to enable students to deal with simple, not trivial RBS spectra and to discuss them in an appropriate scientific language. The materials were prepared for a course of the second level master in modern physics “Innovazione Didattica in Fisica e Orientamento” (Didactic Innovation in Physics and Orientation) for teacher training [9] and, subsequently, employed in various occasions of student involvement in modern physics and hands-on minds-on activities.

2010 - A LEARNING PATHWAY BASED ON VNR DYNAMIC MODELLING SOFTWARE FOR TEACHING SCIENCE IN PRIMARY SCHOOL [Relazione in Atti di Convegno]
Corni, Federico; Giliberti, Enrico
abstract

A proposal for a learning pathway to initiate primary school teachers in model-centred teaching and learning by means of the VnR dynamic modelling software is described. The pathway, suitable for a laboratory course of the Degree in Primary Education, is composed of three increasingly complex activities dealing with experimental work, model design and discussion. Relevant points for reflection upon the dynamic modelling approach, the use of variables and relations, and the transition from simple description to comprehension and interpretation of a phenomenon are discussed.

2010 - A Tool for the Spectroscopic Investigation of Hydrogen-Silicon Interaction [Articolo su rivista]
E., Romano; G. F., Cerofolini; D., Narducci; Corni, Federico; Frabboni, Stefano; Ottaviani, Giampiero; Tonini, Rita
abstract

The preparation of an array of nanocavities (NCs) in silicon via thermal treatments of high-fluence heliumimplantedsilicon is a well established process. The NCs have oered a powerful tool for the preparation of welldefined and ordered internal silicon surface, enabling the experimental investigation of its free energy. Here,instead, we interpret the NCs as an ideal nanolaboratory for the study of the adsorption and desorption of H2on silicon. We will present the determination of the internal pressure through the equilibrium abundances ofmono-hydride dimers and dihydrides obtained with infrared spectroscopy.

2010 - Adsorption equilibria and kinetics of H2 at nearly ideal (2 x 1) Si(1 0 0) inner surfaces [Articolo su rivista]
G. F., Cerofolini; E., Romano; D., Narducci; Corni, Federico; Frabboni, Stefano; Ottaviani, Giampiero; Tonini, Rita
abstract

Silicon nanocavities can be terminated with hydrogen by wet chemical etching. Their infrared spectra can to a large extent be interpreted in terms of silicon monohydrides on H(7 x 7) Si(1 1 1), H(1 x 1) Si(1 1 1) and H(2 x 1) Si(1 0 0), and of silicondihydrides on H(1 x 1) Si(1 0 0). The time evolution under isothermal conditions (600 °C) of the (1 0 0) faces admits a description in terms of transformation from H(1 x 1) Si(1 0 0) into (2 x 1) Si(1 0 0) with simultaneous H2 adsorption onto (2 x 1) Si(1 0 0) neat dimers. In so doing the inner H2 pressure decreases by about one order of magnitude from the initial value of 3000 Torr. The unique properties of nanocavities allow their use as nanoreactors; this has led to the determination of the sticking coecient for H2 adsorption in conditions of pressure, temperature and adventitious contamination otherwise not achievable.

2010 - Analisi dei risultati delle prove OCSE-PISA 2006 a risposta chiusa con l’indicatore di “concentrazione” [Capitolo/Saggio]
Corni, Federico; Mariani, Cristina
abstract

In questo contributo, utilizzando un indicatore denominato “concentrazione”, si intende approfondire come e in che misura l’indagine OCSE-PISA sia utile all’insegnante che decide di somministrare le prove rilasciate ai propri alunni per valutare l’efficacia del proprio intervento didattico. Al fine di una valutazione del processo di apprendimento/insegnamento quello che spesso manca è una valutazione dell’efficacia della procedura di insegnamento in funzione della progettazione degli interventi successivi. In tal senso è opportuno misurare la stessa quantità prima e dopo l’intervento didattico come è ad esempio indicato dal test Force Concept Inventory di D. Hestenes.

2010 - Curricular paths in the SUPERCOMET 2 experimentation in Italy [Relazione in Atti di Convegno]
Corni, Federico; M., Michelini; L., Santi; A., Stefanel; R., Viola
abstract

Supercomet 2 (SUPERCOnductivity Multimedia Educational Tool Phase 2) is a project within the Program Leonardo da Vinci Phase II of the European Union, involving Universities and Secondary Schools of 15 European countries. The objectives of this project are the production of a multimedia tool for teaching superconductivity and the creation of an international community at European level, able to revitalize the teaching of physics in order to open new international collaborations. Several materials have been developed in this framework: interactive animations; texts; videos; hands-on materials for demonstrating and measuring phenomena related to superconductivity and electromagnetism, with an accompanying teacher guide and a teacher seminar. These materials have been used both in teacher seminars and training and in the classroom experimentation in the partner schools. In Italy the University of Udine led and coordinated the experimentation that involved students from several schools within several Italian regions. The planning of the paths by the teachers involved in the project points out various curricular proposals concerning approaches, methods and contents. The analysis of these paths gives a wealth of statements concerning two main ways to look at superconductivity: electric properties and magnetic properties. A report of the main results of the analysis of these paths will be presented.

2010 - Experiments and Models for physics learning in primary school [Relazione in Atti di Convegno]
Mariani, Cristina; Corni, Federico; Altiero, Tiziana; Bortolotti, Carlo Augusto; Giliberti, Enrico; Landi, Laura; Marchetti, Mauro; A., Martini
abstract

The project “Little scientists in the lab: Experiments & Models for science learning in primary school”, funded by the Ministry of Education and being currently under development in Italy, is addressed to primary school teachers of the Faculty of Science Education and consequently to pupils. This project proposes a “Model-centered Learning Environment” to build pilot activities for teaching and learning science and physics, based on experimental and modeling activities. The approach for teacher training is to assign group tasks that promote learning.We set up a website to support teachers’ school activities to facilitate and promote communication and exchange of materials between teachers and researchers of the University of Modena and Reggio Emilia, as well as between the teachers themselves. In this paper, we illustrate the general features of the project and focus on preliminary results of an in-service training for teachers in fluids and electricity.

2010 - Il progetto per la diffusione della cultura scientifica ‘Piccoli scienziati in laboratorio: Esperimenti & Modelli per la formazione scientifica nella scuola primaria' [Relazione in Atti di Convegno]
Corni, Federico; Giliberti, Enrico; Mariani, Cristina; Altiero, Tiziana; Marchetti, Mauro; A., Martini
abstract

Il progetto “Esperimenti & Modelli per la formazione scientifica nella scuola primaria” promosso dal Dipartimento di Fisica e dalla Facoltà di Scienze della Formazione dell’Università di Modena e Reggio Emilia, a cui prendono parte docenti dell’Ateneo provenienti da diversi ambiti disciplinari (matematica, fisica, biologia, scienze della terra e pedagogia), si propone di realizzare attività pilota per la predisposizione di materiali per l’insegnamento e l’apprendimento delle scienze basati sull’impiego dei modelli, denominato Model–centred Learning Environment. L’impatto dell’iniziativa si articola sia a livello locale (formazione iniziale degli insegnanti del Corso di Laurea in Scienze della Formazione Primaria presso la Facoltà di Scienze della Formazione dell’Università di Modena e Reggio Emilia; formazione in servizio e aggiornamento degli insegnanti) che a livello multiregionale (formazione in servizio e aggiornamento). Il coinvolgimento di istituzioni scolastiche e di reti di istituzioni scolastiche in regioni diverse ha lo scopo di verificare le condizioni di replicabilità del modello e di favorirne la diffusione a livello nazionale.In questo contributo verrà presentata la struttura del progetto e i materiali attualmente progettati e realizzati.

2010 - Introduzione elementare all’energia: un laboratorio di scienze per insegnanti di scuola primaria [Relazione in Atti di Convegno]
Altiero, Tiziana; Bortolotti, Carlo Augusto; Corni, Federico; Giliberti, Enrico; R., Greco; Marchetti, Mauro; Mariani, Cristina
abstract

L’insegnamento delle Scienze nella Scuola Primaria deve fornire agli alunni le basi per un approccio scientifico ai fenomeni e ancor prima di proporre temi di discipline separate è opportuno che favorisca la costituzione di un insieme di concetti elementari di fondo comuni e trasversali alle discipline stesse. In ciò gioca un ruolo fondamentale la formazione iniziale degli insegnanti che, anche in considerazione delle linee che si evincono dalle bozze della imminente riforma del Corso di Laurea in Scienze della Formazione Primaria, devono poter usufruire di validi supporti disciplinari, senza però dimenticare la profonda interconnessione delle discipline scientifiche nell’interpretazione dei fenomeni quotidiani e dei processi naturali compresi nel curricolo.Nell’anno accademico 2008-2009 è stato proposto nella Facoltà di Scienze della Formazione un Laboratorio di 16 ore sul tema dell’energia a cui hanno collaborato quattro docenti di diverse discipline scientifiche (Fisica, Chimica, Biologia e Scienze della Terra) e un docente di ambito pedagogico.Il tema dell’energia è stato scelto per il suo carattere di trasversalità alle discipline scientifiche e come contesto paradigmatico in cui costruire un linguaggio e un approccio comune. Il modello energetico adottato si ispira a quello del Karlsruhe Physics Course [1] in cui l’energia è definita a partire dalle sue proprietà di conservazione e introdotta come ente regolatore dei processi naturali. In questo senso viene superata l’idea di “trasformazione dell’energia” introducendo il concetto di “trasferimento di energia” fra portatori, e di esistenza di diverse “forme di energia” pensando piuttosto l’energia come entità sempre associata a un portatore.Il laboratorio è stato aperto con una introduzione sul modello dei portatori e dei trasferitori di energia e si è poi sviluppato con diverse attività di interpretazione da parte degli studenti di situazioni sperimentali riconducibili alle quattro discipline coinvolte. Le attività sperimentali e di interpretazione sono state svolte direttamente dagli studenti, guidati da alcune schede-guida progettare dai singoli docenti e omogenee per tutto il percorso. Prima e dopo l’intervento gli studenti hanno compilato, in modo anonimo, un test di ingresso e un test di uscita.In questo lavoro, dopo una breve introduzione sull’approccio all’energia scelto, verranno presentate in dettaglio la struttura dell’attività del laboratorio e le principali conclusioni che si possono trarre dall’analisi dei materiali prodotti dagli studenti.

2010 - Lens studies without the screen [Articolo su rivista]
Corni, Federico
abstract

A coherent way of introducing lens images is to deal with them in the same way, regardless of whether they are real or virtual: to see the image you just have to look into the lens, toward the track of the light rays. In this direction, an introduction of image formation by a convergent lens, by highlighting also the image-lens mutual positions, can be done using the standard apparatus descibed in this article.

2010 - Modelling and collaboration as cognitive tools in physics education [Relazione in Atti di Convegno]
Corni, Federico; Giliberti, Enrico; Michelini, M.; Santi, L.; Stefanel, A.
abstract

The Green Paper on teacher education in Europe (Buchberger, 2002) highlights the crucial role of designing learning situations in which students can find opportunities to develop structures of meaning, knowledge and activities for a didactical reconstruction of the disciplinary contents, integrated with pedagogical competencies, methodologies and teaching practices.The epistemic role of models in physics (Hestenes, 1996) suggests that models can be included in teaching/learning methodologies and cannot be omitted in a cultural base in the education of teachers of all levels. Being models cognitive tools and not simple representations of phenomena, they cannot be transferred either as ready-to-use examples or taught as rules to apply; to favour interpretation teachers have to offer situated experiences of model building starting from experimental activities.A previous research showed that some elementary recurring basic model structures represent “syntactic elements” of a language oriented to modelling. For instance in the evolution toward equilibrium of different systems is possible to identify the flow of an extensive quantity which is conservative and whose flux intensity depends on the difference of the levels of a corresponding intensive quantity experiencing a resistance.The key role of the group investigation in a cooperative learning environment is implemented in a proposal of a research-based learning pathway based on modelling starting from experiments in a community of perspective primary teachers. The research aims to investigate how the modelling activity takes place during the individual and group exploration of experimental activities and how the collaborative work affects the ability to design models to interpret the observed phenomena. Moreover we analyze the role of single elementary model structure when building complex models with a qualitative modelling software such as VnR.A training pathway was designed, with specific activities and monitoring tools, and tested with a group of perspective primary school teachers of University of Udine (23 students) and University of Modena and Reggio Emilia (73 students).The training pathway was organized in two main activities organized in 4 phases according with tutorial for inquiry learning. Each thematic activity started with the design of an experiment for the exploration of a phenomenon followed by building and testing a model of the observed phenomena, first individually then in small groups. The first activity consisted in the study of phenomena evolving towards equilibrium; the second was in the form of a thought experiment concerning dynamical equilibrium. A final plenary discussion, chaired by the conductor, aimed at analysing to what extent the various model structures are consistent with the observed phenomena as well as to reflection on models comparison (similarities and differences).The software VnR was chosen due o its specifications of icon-based design and representation of simple relations between variables without the use of formulas. VnR is assumed to be an effective tool to let the participants to learn how to think in terms of variables and relations, to identify elementary structures as components of more complex models, to recognize similarities between different phenomena and to develop a dynamical approach to phenomena as processes evolving over time.The data collected during the activities, comprising specific tutorials, based on inquiry learning for all the activities, and models produced by the participants, both alone and in groups, were analysed according to the research questions.

2010 - RBS-Rutherford Backscattering Spectroscopy: Cimentarsi in una tecnica di analisi nella fisica dei solidi [Capitolo/Saggio]
Corni, Federico
abstract

L’intervento alla scuola estiva 2007 per gli studenti delle scuole secondarie superiori si è articolato in diverse fasi su un totale di 6 ore in presenza:1. Introduzione ed avvio delle attività sperimentali a gruppi (1 ora)2. Attività sperimentali a gruppi (1 ora)3. Discussione dei risultati sperimentali (40 minuti)4. Introduzione all’interpretazione di uno spettro RBS (20 minuti)5. Attività individuale di interpretazione di semplici spettri RBS6. Discussione in plenaria dei risultati dell’attività 5 e interpretazione di spettri RBS (2 ore)7. Attività individuale di interpretazione e di costruzione di spettri RBS8. Discussione in plenaria sugli spettri assegnati nell’attività 7 (1 ora)Lo scopo dell’intervento era quello di introdurre le basi della tecnica RBS e di fornire agli studenti i modelli interpretativi per comprendere e discutere autonomamente gli spettri RBS. Si è trattato quindi di far provare agli studenti l’esperienza del ricercatore di fisica della materia che si serve di fenomeni fisici noti e studiati per ottenere informazioni sulla materia dal punto di vista microscopico.

2010 - Tecniche di analisi di fisica della materia e proposte didattiche dai laboratori MASEM: formare gli insegnanti al raccordo tra fisica classica e moderna [Capitolo/Saggio]
Corni, Federico; Ottaviani, Giampiero; A., Mossenta
abstract

La trattazione di un argomento come l’RBS è piuttosto inusuale rispetto ai curricola attualmente proposti nelle scuole; presenta tuttavia numerosi aspetti di interesse che possono candidarlo a trovare una collocazione tra gli argomenti oggetto di insegnamento. Per il suo ruolo all’interno della storia della disciplina può offrire spunti per affrontare le questioni legate allo sviluppo del modello atomico della materia, anche dal punto di vista epistemologico. L’articolo con cui Rutherford ipotizza l’esistenza del nucleo per dare conto dei dati sperimentali ottenuti da Geiger e Marsden può fornire un buon contributo a proposte che privilegiano gli aspetti storico-epistemologici. Tuttavia, altre prospettive interessanti si aprono quando si considerano come strumenti didattici i risultati stessi che si ottengono attraverso l’RBS. L’analisi degli spettri è infatti possibile una volta che sia noto il ruolo delle tre grandezze fattore cinematico, sezione d’urto, sezione di stopping (frenamento); il significato fisico di queste grandezze è invece legato alla trattazione degli urti attraverso i modelli di urto elastico tra masse puntiformi, di diffusione Coulombiana, di frenamento anelastico. I concetti fisici che una trattazione dell’argomento in classe consente di affrontare sono di ambito vasto e significativi rispetto ai contenuti disciplinari, e allo stesso tempo possono essere proposti senza un apparato matematico troppo invadente (a questo proposito, la parte matematicamente più impegnativa, quella relativa alla sezione d’urto, può essere ridotta di molto adottando un approccio probabilistico – sperimentale al concetto, che al contempo aumenta anche il numero di concetti didatticamente rilevanti che si possono introdurre). Inoltre, la consapevolezza che l’apparato teorico alla base della tecnica è del tutto classico aiuta a fornire un quadro d’insieme del dominio della fisica, in cui accanto a fenomeni che devono essere trattati con gli strumenti della meccanica quantistica o con quelli della relatività ve ne sono altri, anche nel mondo microscopico, che continuano ad essere descritti in modo del tutto adeguato dalla fisica classica e che offrono ancora oggi possibilità di sviluppo della conoscenza (la perdita di energia nei materiali è settore di ricerca attuale, anche con tecniche computazionali, come i metodi Monte Carlo). Da non trascurare, in prospettiva didattica, sono gli aspetti motivazionali offerti dal tipo di utilizzo della tecnica, ad esempio nell’analisi di materiali dedicati alle applicazioni tecnologiche più moderne (siliciuri, ad esempio, per l’elettronica) e la natura paradigmatica dell’RBS in chiave epistemologica: sia come esempio di una delle possibili tecniche di indagine collisionali, che sostanzialmente adottano schemi di protocollo simili opportunamente adattati al contesto operativo specifico, sia come contesto per attribuire significato a grandezze, quali la sezione d’urto, che lo mantengono al variare dei fenomeni considerati (urti di particelle subnucleari, trattazione quantistica dell’interazione). L’attualità della tecnica e il suo valore paradigmatico gli conferiscono anche una valenza orientante: operare con le procedure proprie del ricercatore in laboratorio fornisce agli studenti un esempio di come opera un fisico. Alcune proposte per l’introduzione dell’RBS nella scuola superiore sono state elaborate già da tempo, e hanno costituito una base di partenza per la progettazione di un corso per insegnanti di scuola secondaria superiore mirante a fornire strumenti per introdurre nelle classi la fisica moderna. [2]E’ noto che un aspetto determinate per l’inserimento di un argomento nella programmazione del lavoro in classe è il livello di padronanza del docente riguardo ad esso: argomenti non padroneggiati adeguatamente vengono esclusi dalla programmazione. La formazione dei docenti diventa dunque un p

2009 - A Proposal of VnR-Based Dynamic Modelling Activities to Initiate Students to Model-Centred Learning [Articolo su rivista]
Corni, Federico; Giliberti, Enrico
abstract

We propose a laboratory learning pathway, suitable for secondary school up to introductory undergraduate level, employing the VnR dynamic modelling software. It is composed of three increasingly complex activities dealing with experimental work, model design and discussion.

2009 - A proposal for the connection between experiment and modelling for first formation of primary school teachers [Relazione in Atti di Convegno]
Corni, Federico; Giliberti, Enrico; M., Michelini; L., Santi
abstract

The transition between the mere description of a phenomenon and its scientific interpretation-understanding is favoured by the reference to or the construction of models. Modelling is fundamental for the development of a scientific approach to problems in primary school teachers since it helps identifying the relevant variables and the relations between them, formulating hypotheses, and designing experiments suitable to explore and prove such hypotheses. This contribution presents a path of computer-aided didactical activities highlighting the connection between laboratory experiments and dynamical modelling using VnR addressed to teachers in first formation of the Education Faculties of the Universities of Modena-Reggio Emilia and Udine.

2009 - Di che colore è la luce del sole? [Articolo su rivista]
Corni, Federico; S., Panizza
abstract

Nel presente articolo viene riportata parte di un percorso condotto presso la scuola dell’infanzia “Zenit” di Boretto, svolto con gruppi di bambini di età compresa tra i 3 e i 5 anni. Il percorso ha avuto come oggetto d’indagine la luce e il colore. L’interesse nei confronti della luce era scaturito spontaneamente dai bambini: la particolare struttura architettonica della scuola (ampie vetrate e cavedio posizionato al centro) aveva generato interesse verso i raggi del sole.Il percorso progettuale è stato articolato in diverse tappe di lavoro, pensate tenendo presente che il bambino, seppur piccolo, possiede già idee proprie circa molti aspetti della realtà ed è in grado di fare collegamenti e analogie fra le sue esperienze.Come metodologia didattica è stato utilizzato il ciclo composto da tre momenti: previsione, esperimento e confronto. Pertanto ogni esperienza è stata realizzata partendo da un momento iniziale di indagine mirato a far emergere idee, conoscenze e ipotesi dei bambini, poi si è passati all’esperienza diretta ed infine a un momento conclusivo di riflessione per osservare se tale esperienza diretta avesse modificato o confermato le ipotesi espresse in precedenza dai bambini.Le otto tappe comprendevano l’affronto dei seguenti temi: cos’è la luce, la dispersione della luce e l’arcobaleno, il colore degli oggetti e la sintesi sottrattiva, la sintesi additiva e la realizzazione del disco di Newton.

2009 - Evidence for H-2 at high pressure in the silicon nanocavities after dipping in HF solution [Articolo su rivista]
Romano, E.; Cerofolini, G. F.; Narducci, D.; Corni, Federico; Frabboni, Stefano; Ottaviani, Giampiero; Tonini, Rita
abstract

The immersion in HF solutions of silicon containing nanocavities (produced by the annealing at high temperature, 950 degrees C, of silicon implanted with helium at high fluence, 2 X 10(16) cm(-2)) results in the injection of hydrogen in an infrared-mute state (most likely HA into the nanocavities. The pressure achieved in the cavities is sufficiently high to stabilize the hydrogen coverage of the inner surfaces at: temperatures exceeding by 200 degrees C the one of complete desorption from the outer surface.

2009 - Force Concept Inventory: un questionario per valutare l’efficacia dell’insegnamento della dinamica [Articolo su rivista]
Corni, Federico; Mariani, Cristina; V., Gionta; A., Meroni
abstract

In questo articolo viene presentato il questionario Force Concept Inventory progettato per valutare l’efficacia dell’insegnamento della Fisica nell’ambito della meccanica newtoniana. Vengono presentati la struttura del questionario e alcuni problemi allo scopo di metterne in evidenza i riferimenti a concetti e a idee alternative degli studenti, inoltre vengono suggeriti dei metodi di analisi dei risultati con riferimento a due esempi di casi reali.We present the test Force Concept Inventory, designed to evaluate the teaching quality of a Physics course about the Newtonian mechanics. The structure of the test and some of the problems are presented to evidence the references to concepts and misconceptions of the students, moreover some methods of analysis of the results with reference to two actual cases are suggested.

2009 - Hydrogen injection and retention in nanocavities of single-crystalline silicon [Articolo su rivista]
G. F., Cerofolini; E., Romano; D., Narducci; Corni, Federico; Frabboni, Stefano; Ottaviani, Giampiero; Tonini, Rita
abstract

The control of the chemical state of the inner surfaces of nanocavities (NCs) produced by the annealing of helium-implanted silicon has influence on lifetime control, gettering and wafer bonding. In this work it is demonstrated that the etching in HFaq of (1 0 0) silicon containing a buried array of NCs produces a giant injection of hydrogen with the consequent passivation of the inner surfaces, mainly via the formation of silicon monohydride at (1 1 1) faces and monohydride dimers at 2 × 1 reconstructed (1 0 0) faces. These terminations are very stable and survive heat treatments at 700 °C.

2009 - Il microscopio ottico a proiezione come modello per introdurre la microscopia elettronica in trasmissione [Articolo su rivista]
Corni, Federico; Frabboni, Stefano; G., Tigano; V., Pagani
abstract

Viene presentato un percorso composto di attività di laboratorio e di simulazione, indirizzato agli studenti di scuola secondaria di secondo grado, sul microscopio ottico a proiezione allo scopo di introdurre alla comprensione elementare del funzionamento e della formazione delle immagini del microscopio elettronico in trasmissione. Le attività sono progettate in stretta analogia con quello che si svolge al microscopio elettronico; il percorso termina con l’analisi di immagini reali acquisite su un campione di alluminio policristallino in modalità bright field, dark field e alta risoluzione.

2009 - La formazione iniziale degli insegnanti di scuola primaria come problema di ricerca [Capitolo/Saggio]
Corni, Federico; Giliberti, Enrico; M., Michelini; L., Santi; A., Stefanel
abstract

È oggi largamente riconosciuto che per la formazione degli insegnanti è necessaria una riflessione sui contenuti disciplinari in chiave pedagogica. La formazione disciplinare deve fornire capacità di trasferire i concetti fisici in ambito didattico: va quindi affrontato il problema di come realizzare una formazione, che dia strumenti metodologici operativi in situazioni e contesti differenziati. Ciò è particolarmente problematico per futuri insegnanti di scuola primaria, le cui competenze disciplinari sono in genere molto deboli. Questo problema è stato affrontato nell’ambito di Fis21 con studi su problemi specifici, che hanno comportato sperimentazioni di ricerca con gli studenti del corso di laurea in Scienze della Formazione Primaria di Modena e Reggio Emilia e di Udine, che hanno riguardato: a) l’indagine sperimentale come esplorazione guidata intellettualmente, b) la concettualizzazione come ponte tra la visione quotidiana e quella scientifica dei fenomeni, c) la progettazione di attività didattiche per la competenza disciplinare e metodologico-didattica, d) le competenze per la costruzione del pensiero formale.

2009 - Nanocavities in silicon: An infrared investigation of internal surface reconstruction after hydrogen implantation [Articolo su rivista]
E., Romano; D., Narducci; Corni, Federico; Frabboni, Stefano; Ottaviani, Giampiero; Tonini, Rita; G. F., Cerofolini
abstract

The preparation of tetrakaidecahedron-shaped nanocavities in silicon via thermal treatments of high-fluence helium-implanted silicon is a well established process. When the mean distance between Such cavities is on the length scale of the exciton diameter, they are expected to modulate the silicon band structure. This property, however, can hardly be exploited due to the large number of dangling bonds remaining on the cavity inner surface at the end of the process. An easy way to reduce their amount is to passivate them with hydrogen. To investigate the interaction of hydrogen with (i) bulk silicon and (ii) the inner surface of the nanocavities, hydrogen was implanted in silicon on preformed nanocavity arrays and the evolution of the Si-H complexes after isochronal annealings in the temperature range 150-80 degrees C was sensed by infrared spectroscopy in multiple internal reflection geometry. In contrast with previous findings, we will provide evidence that there is no measurable redistribution from bulk defects to inner surface during the thermal treatments. Thus, within the limits of experimental sensitivity. surface passivation was proved to occur upon implantation. Annealing eliminates first the most reactive species (SiH3 and SiH2 above 500 and 550 degrees C, respectively): at higher temperatures only signals related to the remaining H passivation of the ideal reconstructed H (1 x 1)-Si(111). H (7 x 7)-Si(111), and H (2 x 1)-Si(100) Surfaces are observed.

2009 - Process of manufacturing wafers usable in the semiconductor industry [Brevetto]
Ottaviani, Giampiero; Corni, Federico; P., Ferrari; F., Villa
abstract

To manufacture a layer of semiconductor material, a first wafer of semiconductor material is subjected to implantation to form a defect layer at a distance from a first face; the first wafer is bonded to a second wafer, by putting an insulating layer present on the second wafer in contact with the first face of the first wafer. Then, hydrogen atoms are introduced into the first wafer through a second face at an energy such as to avoid defects to be generated in the first wafer and at a temperature lower than 600° C. Thereby, the first wafer splits into a usable layer, bonded to the second wafer, and a remaining layer disposed between the defect layer and the second face of the first wafer. Prior to bonding, the first wafer is subjected to processing steps for obtaining integrated components.

2009 - Un modo di guardare all’educazione scientifica e un approccio di ricerca [Capitolo/Saggio]
Corni, Federico; M., Michelini; L., Santi; A., Stefanel
abstract

Le ricerche condotte dall’Unità di Udine si collocano nel quadro delle ricerche empiriche, finalizzate a contribuire alla pratica didattica e a produrre proposte di Insegnamento/Apprendimento (I/A), ma non sono ristrette a ciò che funziona nella pratica. Sono orientate allo studio della costruzione del pensiero formale nei più piccoli (scuola dell’infanzia e primaria) e delle idee di base della fisica moderna nei ragazzi di scuola secondaria . Affrontano pertanto il ruolo di aspetti metodologici peculiari, come il gioco, l’operatività, il problem solving, l’educazione informale nei processi di apprendimento, mentre mirano a produrre materiali didattici a sostegno dell’innovazione e ad orientare la pratica con metodologie di ricerca e sviluppo. Gli approcci nella ricerca non sono puramente basati su aspetti di contenuto disciplinare: si pone infatti attenzione anche a variabili di contesto, che influenzano il modo di porsi dello studente. Nel progettare nuove proposte di I/A si pongono su piani di uguale rilevanza aspetti legati al dominio scientifico, ai bisogni degli studenti ed agli ambienti di apprendimento, soprattutto per individuare approcci efficaci all’evoluzione delle idee da quelle di senso comune a quelle scientifiche.

2008 - A proposal about Rutherford Backscattering Spectrometry for a second level master in physics education [Relazione in Atti di Convegno]
Corni, Federico
abstract

Most of the techniques for material science are based on quantum mechanics, since matter is studied in terms of interactions with its microscopic components (e.g. atoms, nucleuses and electrons) or aggregates of them (e.g. crystals, phonons). However, due to the strong orientation of the techniques to gain qualitative or quantitative information (doing measurements), they are often interpreted according to semi-classical or classical models (e.g. the effective mass for conduction of a charged particle, the electron gas in a metal, the phonon as a harmonic oscillator). In this sense, the analysis techniques can be introduced in physics education as a bridge between classical physics and quantum mechanics with its applications. Rutheford Backscattering Spectrometry (RBS) is an analysis technique largely used in material science and it constitutes a candidate technique for secondary school level or university students.The didactical proposal presented below follows our previous experience and research works about the introduction of the analysis techniques into the curriculum of secondary school and benefits from our direct involvement in the use of RBS for condensed matter analyses. The aim of the activity is to enable students to deal with simple, not trivial, RBS spectra and to discuss them in an appropriate scientific language. The materials were prepared for a course of the second level master in modern physics “Innovazione Didattica in Fisica e Orientamento” (Didactic Innovation in Physics and Orientation) for teacher training.

2008 - Physics research coming into school [Relazione in Atti di Convegno]
M., Michelini; D., Cenadelli; Corni, Federico; V., Engstrom; A., Kaminska; A., Karbowski; G., Karwasz; J., Kruk; H., Nowakowska; G., Osinski; L., Santi; A., Testa; T., Wroblewski
abstract

In many countries, this is for example the case of Poland, the shifting of intellectual interests towards “not-strictly-science” sciences leads to shrinkage of physics programmes in secondary schools. Obviously, it does not seem reasonable to eliminate from school programmes Galileo’s laws of kinematics or Newton’s lawsof dynamics. At this point, teaching Physics risks to become a kind of “mentalexercise” – more as exemplification of mathematics than introducing into richness of problems of Physics itself.A possible recipe for this dilemma is introducing element of “live”, i.e. Modern Physics. Several such examples arrive from Italian secondary (lyceum) school system.The work in the DW “D” workshop Physics research in the classroom was greatly based on these examples.The main contributions to the Workshop came from:1) Davide Cenadelli and Antonella Testa from Università degli Studi di Milanoon Astrophysics2) Lorenzo Santi and Marisa Michelini from Università degli Studi di Udine on Physics of Elementary Particles3) Federico Corni from Università degli Studi di Modena on Solid State Physics4) Andrzej Karbowski, Grzegorz Osiński and Grzegorz Karwasz from Uniwersytet Mikołaja Kopernika, Toruń on Quantum Colllisions and on CosmologyIn the discussion participants from Belgium, Bosnia and Herzegovina, Norway, Poland, Italy took part. In addition to the scientific and didactical matters, the need for exchanging practical information (what kind of equipment, which are the waysof funding) was stressed in the discussion. Finally, we also presented the outcomes of two EU projects developed on Modern Physics and on Superconductivity and Polish Programme on Science Centres.

2008 - Primi passi sull’elettrostatica [Articolo su rivista]
Corni, Federico; E., Ferrari; G., Vaccari
abstract

Nel presente articolo viene riportata la progettazione e i risultati più significativi della sperimentazione di un percorso sull’elettrostatica rivolto a bambini di 5 anni della scuola dell’infanzia comunale “Villaggio Giardino” di Modena.L’argomento dell’elettrostatica si presta a verificare se temi scientifici, anche complessi e che richiedono un certo grado di astrazione, possano essere affrontati con bambini molto piccoli avvalendosi ad esempio di proposte innovative di educazione informale, per costruire un ponte tra l’esplorazione spontanea e quella organizzata a scuola, nonché per favorire occasioni di attività sperimentale e per mettere l’operatività a disposizione dell’apprendimento. Ciò non significa che già nei primi anni di scuola dell’infanzia i bambini siano chiamati a sviluppare concetti scientifici, ma che proprio a partire da questa età vengano stimolati a creare alcuni modelli elementari propedeutici alla successiva formazione di modelli e concetti più complessi. La sfida è quella di introdurre i bambini ad un approccio alla realtà che dia respiro e senso a un pensiero scientifico che già appartiene loro naturalmente e spontaneamente, sostenendolo e alimentandolo attraverso l’offerta di contesti e situazioni specifiche e stimolanti.Dal punto di vista disciplinare, si intendono affrontare i seguenti punti: l’elettrizzazione per strofinio e per induzione, gli stati di elettrizzazione e l’interazione elettrostatica. Si ritiene opportuno non far riferimento ad alcun modello microscopico e considerare il fenomeno dell’elettrizzazione come uno stato assunto dalla materia.Sono state proposte attività in cui si sono evidenziati i comportamenti particolari di alcuni materiali ponendo i bambini di fronte a quesiti da risolvere, per cui dovevano cercare la spiegazione più logica e coerente dell’intero contesto. Sono state utilizzate metodologie di lavoro che hanno consentito di far emergere e sviluppare, tramite esperimenti in sezione in contesti ludici informali, le idee interpretative spontanee dei bambini.

2008 - Superconductivity in Italian Secondary Schools: the experimentation carried out by Udine University with Supercomet2 (SC2) materials [Relazione in Atti di Convegno]
M., Michelini; L., Santi; R., Viola; Corni, Federico
abstract

Through a highly interactive tools on CD, which comprises animation and films of demonstrative experiments, and uses modern pedagogical methods, such as collaborative learning and problem solving, the Supercomet 2 Project (SUPERCOnductivity Multimedia Educational Tool phase 2 of the European Union) aims to introduce superconductivity to European high school curriculums. During the first year of the project the following were produced: a CD-ROM with didactic material, a teacher’s guide to clarify characteristics and roles of support material (texts, worksheets and computer presentations) and preview didactic courses. During the second year of the project It was: translated the material into the languages of countries participating in the project, experimented the application in high school classes in various parts of Europe, tested the updating course and the teacher’s guide with a group of reference teachers. At the end of the first period of experimentation and dissemination were revised and new material was integrated in order to produce a final version at the end of the project. Further integrated proposals have been included with the revised material. In this paper the main characteristics realized during the project will be described.

2008 - The secondary school experimentation of SUPERCOMET in Italy [Relazione in Atti di Convegno]
R., Viola; M., Michelini; L., Santi; Corni, Federico
abstract

SUPERCOMET is a project within the program Leonardo da Vinci phase II of the European Union and is of what will be the final product of this project: a multimedia tool for teaching superconductivity addressed in particular to secondary school students. The objective of the project in addition to producing the multimedia tool is to create an international community at an European level able to revitalize the teaching of physics in order to open new international collaborations.Through a highly interactive application on CD which comprises animation, films of demonstrative experiments, and uses modern pedagogical methods such as collaborative learning and problem solving, the project aims to introduce superconductivity to European high school curriculums. During the first year of the project the following were produced:- a CD-ROM with didactic material- a teacher’s guide to clarify characteristics and roles of support material (texts, worksheets and computer presentations) and preview didactic courses. During the second year of the project It was: • translated the material into the languages of countries participating in the project;• experimented the application in high school classes in various parts of Europe; • tested the updating course and the teacher’s guide with a group of reference teachers; At the end of the first period of experimentation and dissemination various corrections were made and new material was integrated in order to produce a final version at the end of the project. Further integrated proposals have been included with the revised material.

2007 - Analisi quantitativa della progettazione in web di percorsi didattici di insegnanti di scuola primaria in prima formazione [Relazione in Atti di Convegno]
Corni, Federico; P., Fornasier; A. M., Gibertoni; M., Michelini
abstract

La progettualità ha un ruolo importante nella formazione degli insegnanti. Essa favorisce lo sviluppo di competenze professionali integrandovi apprendimenti disciplinari, come rielaborazione di modelli, strategie, metodi e materiali per l’insegnamento. La collaborazione arricchisce e forma a questo compito per la ricchezza derivante dall’apporto di più individui, per l’apertura di prospettive introdotta dai diversi punti di vista, per l’intrinseca dimensione critica e riflessiva che comporta.Il lavoro a distanza favorisce e potenzia questa collaborazione, lasciando a ciascuno la libertà del tempo di riflessione e del momento di intervento. In web mette inoltre a disposizione reti di risorse, che si integrano ai contributi individuali. Da un punto di vista della ricerca, il lavoro collaborativo in rete è un importante contesto, fonte di materiali e dati per l’analisi e lo studio delle modalità di interazione fra le persone. Anche solo un’analisi quantitativa su base statistica dei materiali prodotti e memorizzati in rete evidenzia le qualità delle strategie e dei comportamenti che le persone utilizzano per eseguire il lavoro progettuale.In questo lavoro si presenteranno i dati ricavati da un lavoro collaborativo in rete da parte di studenti del Corso di Laurea in Scienze della Formazione Primaria di due sedi universitarie, la sede di Udine e quella di Modena e Reggio Emilia, per la progettazione di percorsi didattici sulle macchine semplici. Si analizzeranno i dati della fase finale vera e propria di scrittura collaborativa.

2007 - The basic models in the experimental work of student-teachers of primary school [Relazione in Atti di Convegno]
Corni, Federico; Giliberti, Enrico; M., Michelini; A., Stefanel
abstract

This work, issued from an ongoing collaboration between the researchers in Physics education of the Universities of Udine and Modena-Reggio Emilia, focuses on an educational and training process which allows to bridge experimental work and formal thinking, thus providing professionalizing bases to teachers to-be. This process was performed within the course in “Design of Educational Experiments” which is a part of the degree course in Primary Education, placing the student-teachers in a critical position by proposing project activities which implied reflection not only on the operational elements of the organization of simple experimental activities for children, but also - and mainly - on the role of such activities in science education. The students were asked to illustrate the models underlying specific sets of experimental activities and to discuss their reflections upon these models. For the design and reflection phases the students could benefit from the opportunity to design activities using specific materials, as well as sufficient time for discussion through a web-based environment supplying web-forums and a cooperative writing tool.

2006 - Formal and informal aspects of the teacher formation: an open distance-learning context for educational design on simple machines [Relazione in Atti di Convegno]
Corni, Federico; M., Michelini
abstract

A solid and widespread scientific culture can be achieved if science education and in particular physics education start very early, together with the first experiments in observing and representing the world around, at nursery and primary school; therefore the teachers have to be formed for this task.Several studies on people’s familiarity with physics report that it is scanty, often resulting from a reductionist teaching method, based on a synthesis of the main ideal laws offered as a basic set of knowledge which can be applied to any context. Pre-service education and training of teachers, started in 1998 in many Italian universities more than eight years [4] after the law which had instituted it (law no. 341/1990), is an opportunity that should not be missed, in order to offer the new generations of teachers a knowledge of physics which is solidly anchored to their professionalism, so as to be used it in children’ education.Educational design is one of the main professional skills, so an important issues to be dealt with in pre-service training is to provide the teachers with basic scientific culture which may enable them to perform successful educational design in spite of their limited knowledge of the subject. A joint research experiment on educational path design was carried out by researchers of the Universities of Modena and Reggio Emilia and of Udine within the course in Design of Educational Experiments which is common to the degree courses in Education of both University sites. During the experiment a model of blended activity and a prototype of interactive web-based environment were developed. The web-supported joint activity completing the training path, object of this paper, consists in the in-depth study of an assigned topic, in the search for experimental solutions and in the design of educational paths. The subject chosen was simple machines. In this paper will be analyzed the contribution of the web-supported cooperation work to the connection between knowledge in the discipline, the knowledge contextualized with experiments or applications, and the psycho-pedagogical knowledge for educational path design.

2006 - The Gibbs phase rule: an experimental path for its recognition and application [Articolo su rivista]
Corni, Federico; M., Michelini
abstract

This paper proposes a conceptual path about a theme which lies at the border between physics and chemistry, which, though usually neglected, is nowadays very important in materials science: the Gibbs phase rule. It is illustrated by means of significant measurements aimed at clarifying the concepts involved (i.e. phase and degree of freedom), at extracting the phase rule itself on a phenomenological basis, and applying it as an interpretative tool. The main steps suggested for an educational path are the following: elementary experiments and discussion for a glossary, measurements of the temperature as a function of heating or cooling time for mixtures with different compositions, experimental data observation in graphical form to recognize the indicators of the phase transitions which occur, compilation of tables of the quantities involved in the phase rule, and discussion and identification of the phase sequence during the processes.

2006 - Water tank experiment clears up some refraction misconceptions [Articolo su rivista]
Corni, Federico
abstract

The well-known figure of a straw in a glass of water, often reported in textbooks to introduce light refraction, is hardly understandable in physical terms and can even be misleading when accompanied with the scheme of a deviated light ray to introduce Snel’s law. This paper means to propose an alternative way of introducing light refraction to pupils, aimed at preventing misconceptions.

2006 - X-ray reflectivity study of hydrogen implanted silicon [Articolo su rivista]
P., Dubcek; B., Pivac; S., Bernstorff; Corni, Federico; Tonini, Rita; Ottaviani, Giampiero
abstract

The X-ray reflectivity (XRR) technique was used to study monocrystalline silicon samples implanted with H-2 ions at an energy of 31 keV and to the dose of 2 x 1016 hydrogen atoms/cm(2). All samples were subsequently isochronally annealed in vacuum at different temperatures in the range from 100 to 900 degrees C. Although the hydrogen depth distribution was expected to be smooth initially, fringes in the XRR spectra were observed already in the implanted but not annealed sample, revealing the presence of a well-defined film-like structure. Annealing enhances the film top to bottom interface correlation due to structural relaxation, resulting in the appearance of fringes in the larger angular range, already at low annealing temperatures. The thickness of the film decreases slowly up to 350 degrees C where substantial changes in the roughness are observed, probably due to the onset of larger clusters formation. Further annealing at higher temperatures restores the high correlation of the film interfaces, while the thickness decreases with the temperature more rapidly. (c) 2006 Elsevier B.V. All rights reserved.

2005 - A physics learning proposal on phase diagrams [Capitolo/Saggio]
Corni, Federico; Michelini, M.
abstract

In this paper we present a didactic activity on the phase diagrams which are at the basis of different technological processes involving materials with peculiar properties, but which are also relevant to everyday life substances. Our proposal is a learning tool on phase transitions, based on computer on line experiments and problem solving activities. In particular it is oriented to the analysis of: a) unary pressure-temperature diagram, where equilibrium lines between phases are present which converge into the triple point; b) binary diagram, where the lines delimit the region of coexistence of solid and liquid phases of two completely miscible substances; c) eutectic diagram, where lines incident in the eutectic point mark the boundaries of adjacent regions of coexistence of solid and liquid phases of two substances with limited solubility.

2005 - ANALISI DI CASE STUDY SULLA FORMAZIONE ALL’INSEGNAMENTO SCIENTIFICO DI DOCENTI ELEMENTARI A REGGIO EMILIA E A UDINE [Relazione in Atti di Convegno]
Corni, Federico; M., Michelini; A., Stefanel
abstract

La formazione degli insegnanti della scuola di base ed elementari in particolare richiede l’integrazione della formazione in campo disciplinare con quella in ambito pedagogico e psicologico. È necessaria, pertanto, una preparazione di base di natura culturale in fisica e quindi una consapevolezza dei nodi concettuali e delle metodologie proprie disciplinari. La formazione disciplinare deve poi fornire capacità di trasferire i concetti fisici in ambito didattico. Va quindi affrontato il problema di come realizzare una formazione che dia strumenti operativi in situazioni e contesti differenziati producendo professionalità docente.In molti casi, nella formazione degli insegnanti si opera formando separatamente alla professionalità docente e alla competenza disciplinare, lasciando la sintesi all’apprendente. Come emerge dalla letteratura questo modo di procedere non consente di costruire la professionalità docente.Sono stati proposti diversi modelli formativi, che fanno riferimento a materiali didattici e a strategie operative in forma metaculturale, esperienziale o situata. Il modello metaculturale si attua in seminari o illustrazioni per iscritto riguardanti sintetiche documentazioni e valutazioni di attività di insegnamento, analisi critiche di articoli di ricerca e/o proposte innovative. Lascia tutto il lavoro di integrazione, rielaborazione e traduzione operativa all’autonomia dell’insegnante ed è efficace nella misura in cui crea risonanze con il suo background epistemologico, metodologico, disciplinare, didattico. Ha quindi prevalenti potenzialità per la formazione in servizio rispetto a quella iniziale.Il modello esperienziale, in cui il docente vive la proposta didattica che verrà fatta allo studente, è tuttora alla base di molte attività formative mirate all’introduzione delle nuove tecnologie. Risulta particolarmente efficace se sono previsti elementi di flessibilità nella progettazione dell’intervento in classe.Il modello situato nasce nel contesto della formazione in comunità di pratiche professionali e prevede che, seguendo le proposte dei singoli, si realizzino attività differenziate compatibili con le dinamiche innescate nel contesto delle singole classi. Fornisce forti elementi professionalizzanti, a rischio tuttavia di lasciare solo l’insegnante nella gestione del lavoro in classe.I limiti dei diversi modelli fanno emergere la centralità del problema della individuazione di strategie per la formazione iniziale dei docenti che saldino cultura fisica e competenze didattiche.Il nostro lavoro parte dal presupposto che nella formazione iniziale dei docenti sia necessario formare alla disciplina attraverso la didattica della stessa, realizzando azioni formative in cui la dimensione progettuale e di riflessione su elementi propositivi per la didattica sono interni al processo formativo. Il coinvolgimento personale, inoltre, è assunto essere efficace nel momento in cui è operativo e sono definiti compiti da svolgere e obiettivi da raggiungere. Abbiamo individuato strategie differenziate di intervento basate su tali presupposti e caratterizzate sul mettere in situazione e realizzare coinvolgimento operativo. E’ stato scelto di offrire strumenti non completamente definiti perché la fase di rielaborazione e progettuale sia essa stessa parte della strategia formativa, integrando formazione professionale e formazione disciplinare.La ricerca di cui si riferisce in questa sede mira allo studio dell’impatto sulla formazione iniziale degli insegnanti di tale strategia. L’analisi si incentra sullo sviluppo della capacità critica e progettuale per la costruzione di competenze professionali in didattica della fisica, con particolare riguardo alla pianificazione di singole attività sperimentali e di catene esplorative di tipo sperimentale.

2005 - Costruire i diagrammi di fase dai dati sperimentali: una proposta didattica [Articolo su rivista]
Corni, Federico; Ottaviani, Giampiero; M., Michelini
abstract

In this paper an educational laboratory work on phase diagrams is presented. The phase diagrams are at the basis of many technological processes involving materials with peculiar properties to produce artifacts of our everyday life. Our proposal is a learning tool on phase transitions, based on computer on line experiments and problem solving activities. In particular it is oriented to the analysis of: a) unary pressure-temperature diagram, b) binary lens-like diagram, and c) binary eutectic diagram. The proposal is thought to gradually proceed towards increasing difficulties so that the activities can be selected and used at various levels.

2005 - Materials science and optics in the arts: case studies to improve physics education [Relazione in Atti di Convegno]
Corni, Federico; Ottaviani, Giampiero; M., Michelini
abstract

It is nowadays universally recognized that the training of teachers, especially primary school teachers, requires integration of the education in physics and in the psychological and pedagogical fields.Therefore, a cultural background in physics is necessary, as well as knowledge of the conceptual difficulties and of the teaching methods typical of the discipline itself. The formation in a specific field of knowledge has to provide teachers with the capability of transferring concepts.Hence the problem is how to realize a formation supplying educational tools for different situations and contexts, therefore improving teaching competences. Different educational models have been proposed, referring to teaching equipments and operational strategies in meta-cultural, experiential, or situated forms.This work moves from the assumption that pre-service training of teachers requires education in this discipline through the teaching of the discipline itself. This objective can be achieved by means of teaching activities in which the planning as well as the reflection on didactical proposals are an integral part of the teaching process. Moreover, the direct involvement is considered to be effective only when it is operative and tasks and goals to be reached are clearly defined.We have selected different strategies based on such hypotheses and characterized by putting in situation and by realizing operative involvement. Not completely defined instruments have been offered to the students because the elaboration and the planning phases are considered part of the intervention therefore integrating professional formation with disciplinary formation.The present research refers to the study of the impact of such a strategy on the initial teacher formation. The analysis is centred on the improvement of critical and planning capacities for the construction of professional competences in physics education, with particular care to the planning of single experimental activities, of explorative experimental chains and of maps and conceptual networks for the definition of paths for formal instruments management, either for personal exploration, or for didactical proposal definition.

2005 - Physics and Art: introducing light-matter interaction by looking at famous paintings [Capitolo/Saggio]
Corni, Federico; Ottaviani, Giampiero
abstract

The colour of an object is a subjective sensation produced by a series of phenomena connected to the interaction between matter and electromagnetic waves. Our eyes incessantly convey images and information to us, but hardly ever do we stop to consider their physical origin. We are enchanted by the colours of spring, we marvel at the beauty of a butterfly’s wings, we are carried away by the sight of a picture and yet we ignore that these sights are the result of the interaction between light in the environment and the material of the bodies’ surface. Such an attitude originates spontaneous explanatory hypotheses which tend to take root, such as those of colour being one of the properties of an object and light being a neutral entity which gives luminosity to objects. This position does not allow a scientific approach to reality and therefore it does not allow quantification of the phenomena. Unfortunately scientific models of phenomena often require mathematical or geometrical formalism, and therefore they are often seen by the students as being an end in themselves, having no evidence in reality and no practical use; for this reason, they may not be considered to represent an actual advance in learning.Art is probably the most suitable context to introduce the phenomena connected to light-matter interaction, since painters know well - at least from a practical point of view - that the final result of their work is given by their capability to control these phenomena.

2005 - Progettazione in rete telematica di proposte didattiche nella formazione degli insegnanti di scuola primaria [Relazione in Atti di Convegno]
Corni, Federico; P., Fornasier; M., Michelini; C., Virgili
abstract

Le difficoltà di apprendimento in campo scientifico, legate all’influenza del senso comune sull’interpretazione dei fenomeni, individuate da una vastissima letteratura, hanno focalizzato l'attenzione della ricerca didattica sui problemi cognitivi e di apprendimento, ponendo nuove sfide per l’educazione scientifica.La formazione iniziale degli insegnanti richiede particolare attenzione a queste problematiche per superare i problemi di analfabetismo scientifico emersi con l’indagine PISA e quelli legati a modelli riproduttivi e trasmissivi mutuati dai testi e da una didattica antica. Recenti studi sulle strategie formative di insegnanti in prima formazione hanno messo in evidenza che è necessario trattare la disciplina attraverso la didattica della stessa, realizzando azioni formative in cui la dimensione progettuale e di riflessione su elementi propositivi per la didattica sono interni al processo formativo. Il personale coinvolgimento del soggetto con l'oggetto di studio, l'operatività manuale e concettuale nei processi interpretativi, l'analisi condivisa di potenzialità e limiti dell'interpretazione sono la condizione per l'apprendimento. Lo studio della discussione tra pari in presenza, come elemento per un apprendimento significativo, è da tempo al centro della ricerca. Da alcuni anni si stanno sperimentando forum e brainstorming in rete con le stesse finalità. Le attività realizzate in rete sono frutto dei modelli teorici sulla didattica a distanza sviluppati negli ultimi anni in collaborazione con alcune Università italiane. Si creano ambienti di apprendimento in cui il discente intreccia le sue relazioni con persone e materiali per costruire conoscenza mediante un percorso, che trova nell’ambiente stesso la mappa logica, che relaziona background culturale, scelte metodologiche, contenuto disciplinare, percorso progettuale e contesto educativo. Ambienti web flessibili ed interattivi in cui effettuare una comunicazione a distanza, sincrona ed asincrona, attivata da un lavoro preliminare in presenza e secondo precisi schemi di lavoro, costituiscono il contesto in cui offrire occasioni di formazione alla progettualità e alla collaborazione tra pari, per imparare a gestire in comunità di pratiche la propria crescita professionale. Principalmente per il fatto di essere indipendenti dal luogo e dal tempo e basate su un linguaggio testuale e ipertestuale si attua infatti, insieme al rapporto uno a uno o uno-molti, il rapporto molti-molti.Il tema scelto per l’esperienza pilota di educazione alla progettualità in rete telematica è quello delle macchine semplici, per diversi motivi. Si trovano ovunque, dagli utensili di uso comune, al corpo umano, alle macchine più complicate. La comprensione del loro funzionamento coinvolge concetti di meccanica come quello di forza e di vincolo, di momento di una forza e di energia, che sono temi chiave e basilari della meccanica, spesso di difficile comprensione da parte degli studenti. Esse si prestano a creare Learning Objects, che possono diventare oggetto di sperimentazione di una didattica innovativa, basata sulle nuove tecnologie e sull’e-learning, in cui personale coinvolgimento e progettualità costituiscano metodo di lavoro.I problemi di ricerca posti nel presente lavoro sono in particolare i modelli di comprensione degli studenti, che emergono grazie al lavoro in rete, le modalità e le soluzioni che gli studenti applicano o tendono a preferire nella comunicazione e nella collaborazione via web, e le difficoltà e i vantaggi che essi incontrano rispetto a un tipo di apprendimento tradizionale.

2005 - Riconoscimento grafico elementare di un fenomeno esponenziale: dall’analisi qualitativa a quella quantitativa [Relazione in Atti di Convegno]
Corni, Federico; L., Magnago
abstract

La fisica per tematiche è una modalità di insegnamento che privilegia la presentazione della disciplina in modo trasversale a partire dai modelli descrittivi e interpretativi rispetto alla presentazione sequenziale degli argomenti. La fisica è così presentata evidenziandone l’unitarietà e la coerenza e nello stesso tempo vengono fornite agli studenti competenze nel ragionare per modelli, coerentemente ai campi di validità, potenzialità predittive e limiti. Ciò richiede da parte degli insegnanti che i modelli siano presentati in maniera corretta e completa.In questo articolo si intende presentare un contributo all’insegnamento del modello esponenziale. Si focalizzerà l’attenzione sulla funzione del tipo exp(-alfa t), con alfa positivo, come modello di una vasta classe di fenomeni fisici che per la loro semplicità possono essere adottati come tematica trasversale di insegnamento della fisica. Si analizzerà in particolare una modalità di affronto del modello esponenziale per una strategia di insegnamento basata sull’esperimento che richiede solo la conoscenza di strumenti matematici elementari. Si metteranno in evidenza, in una proposta di percorso per gli studenti con note per l’insegnante, gli aspetti qualitativi e quantitativi offerti da un metodo grafico per il riconoscimento del comportamento esponenziale e la valutazione del tempo caratteristico tC = alfa^(-1) tenendo conto degli errori dovuti alle approssimazioni.

2005 - SUPERCOMET: uno strumento multimediale per l’insegnamento della superconduttività [Relazione in Atti di Convegno]
Corni, Federico; M., Michelini
abstract

SUPERCOMET è un progetto del programma Leonardo da Vinci fase II dell’Unione Europea. Ha avuto inizio, nella sua prima versione, nel dicembre 2001 e si è concluso nel dicembre 2004. Immediatamente dopo è stato varato il progetto SUPERCOMET 2 che è tuttora in corso e che finirà nel 2006. SUPERCOMET dà il nome a quello che sarà il prodotto finale del progetto: uno strumento multimediale per l’insegnamento della superconduttività rivolto in particolare agli studenti della suola secondaria superiore. Gli obiettivi del progetto, oltre a quello di produrre lo strumento multimediale, sono quelli di creare una comunità internazionale a livello europeo con competenze nel rinnovamento dell’insegnamento della fisica e di aprire vie di comunicazione e stabilire contatti stabili fra le organizzazioni di insegnanti di fisica, ricercatori in didattica della fisica e autorità competenti nella stesura dei curricoli. In questo lavoro verranno descritte le caratteristiche dello strumento multimediale nel suo stato attuale e indicati gli sviluppi futuri.

2005 - Sensori on-line per la formazione iniziale di insegnanti in fisica a Udine, Modena e Bolzano [Relazione in Atti di Convegno]
Corni, Federico; M., Michelini; A., Stefanel; L., Santi
abstract

Le nuove tecnologie consentono l’utilizzo di strategie e metodologie didattiche, che sono: efficaci nell’aggredire quei nodi concettuali ostacolo all’apprendimento; risonanti con i modi propri con cui la fisica indaga il mondo; motivanti per i ragazzi. Tali strategie prevedono l’utilizzo di sensori collegati in linea con l’elaboratore per la graficazione in tempo reale delle grandezze che descrivono l’evoluzione del sistema in osservazione. Impiegano schede di lavoro che favoriscono lo sviluppo di competenze metodologiche nel formulare ipotesi, per metterle a confronto con i dati sperimentali. Presso tre sedi SSIS sono state realizzate sperimentazioni di moduli formativi per insegnanti di tipo esperienziale su stati e processi termici e cinematica, che integrano attività sperimentali in laboratorio e di riflessione disciplinare e didattica in presenza e in rete. I risultati hanno evidenziato che gli specializzandi superano le difficoltà nel passaggio dalla dimensione qualitativa a quella quantitativa per la costruzione di relazioni a partire da esperimenti reali. Il coinvolgimento in un personale processo di apprendimento attiva il riconoscimento dell’efficacia di strategie basate sull’uso delle TIC e in particolare dei sistemi di rappresentazione grafica in tempo reale. Appare irrinunciabile nella formazione insegnanti una successione di attività che li impegnino in questo compito.

2005 - Un percorso sulla regola delle fasi per i sistemi binari utilizzando i sensori di temperatura [Relazione in Atti di Convegno]
Corni, Federico; M., Michelini
abstract

L’utilizzo delle nuove tecnologie favorisce lo studio di processi complessi di fisica difficilmente affrontabili con le attrezzature del laboratorio tradizionale. Della termodinamica dei materiali, ad esempio, tramite misure di temperatura coi sensori interfacciati col computer, si possono trattare le proprietà di equilibrio fra le fasi di sistemi binari, superando il caso elementare e spesso semplicistico delle sostanze pure. In questo contributo verrà presentato un percorso didattico di attività di laboratorio utilizzando le nuove tecnologie volto al riconoscimento e all’utilizzo della regola delle fasi quale strumento descrittivo e interpretativo del comportamento dei sistemi binari. Saranno introdotti concetti di base quali quello di fase e di gradi di libertà.

2005 - Vibrational spectroscopy study of Ar+-ion irradiated Si-rich oxide films grown by plasma-enhanced chemical vapor deposition [Articolo su rivista]
G., Mariotto; G., Das; A., Quaranta; G., DELLA MEA; Corni, Federico; Tonini, Rita
abstract

SiOx thin films with different stoichiometry degree were obtained by plasma-enhanced chemical vapor deposition on crystalline silicon substrates from SiH4 and N2O gas mixtures. Two twin sets of samples were irradiated by 380 keV Ar+ ions at a fluence of 5×1016 ions/cm2 at room temperature and at 500 °C, respectively, and then annealed in vacuum at different temperatures, between 500 and 1100 °C. A set of unirradiated samples has been annealed in the same conditions in order to discriminate the contribution of ion irradiation and of thermal treatments to the changes of the film microstructure. The structural modification of the oxide network and the growth of Si nanoclusters have been studied by vibrational spectroscopy techniques. Fourier transform infrared absorption spectra evidenced that ion irradiation induces a hydrogen loss of about 50%, and that postirradiation thermal treatments lead to the recovery of the irradiation defects and to the out diffusion of the residual hydrogen. After heating at 800 °C, irradiated and unirradiated samples exhibit substantially the same structure from the point of view of infrared-absorption spectra. In the meanwhile, the Si-O-Si stretching peak blue shifts, but never reaches the wavenumber value of pure silica owing to the presence of nitrogen into the network. Raman spectra of as-irradiated films reveal the presence of an amorphous silicon phase within the damaged layer of the oxide matrix. Raman spectra of irradiated samples undergoing thermal treatments at high temperature indicate a rearrangement of the film microstructure with the progressive clustering of the amorphous silicon phase. However, no clear spectroscopic evidence is gained about the crystallization of silicon nanoclusters, even after annealing at the highest temperature. In fact, the Raman scattering from silicon nanocrystals is partially hidden by the Raman peak of the c-Si substrate.

2004 - Copper–titanium thin film interaction [Articolo su rivista]
L., Castoldi; G., Visalli; S., Morin; P., Ferrari; S., Alberici; Ottaviani, Giampiero; Corni, Federico; Tonini, Rita; Nobili, Carlo Emanuele; M., Bersani
abstract

Interaction between 5 mum thick copper and 50 nm thin titanium films was investigated as a function of annealing temperature and time using MeV He-4(+) Rutherford backscattering, X-ray diffraction and dynamic Secondary Ion Mass Spectrometry. Samples were made by depositing 10 nm of titanium on a PECVD silicon oxynitride, followed by 50 nm of titanium nitride and 50 nm of titanium in the said order. In the same system 100 nm of copper were subsequently sputtered; finally 5 mum of copper were grown by electroplating. This complex structure was chosen in order to investigate the possibility of using copper interconnects also in power devices. To investigate the composition and growth of Ti-Cu compound on the buried interface, it was necessary to develop a special procedure. The results of the investigation show the formation of a laterally non-uniform layer of TiCu4, which is presumably preceded by the formation of CuTi. The growth of the compound is kinetically controlled by means of a diffusion coefficient having 1.7 eV activation energy and a 5 x 10(-2) cm(2)/s pre-exponential factor. The formation of a titanium-copper compound ensures a reliable and low resistance electrical contact especially at the vias. The Ti/TiN/Ti acts efficiently as a sacrificial and inert diffusion barrier. No copper was detected on the silicon oxynitride surface even after a 20-min 500 degreesC heat treatment.

2004 - GISAXS Study of Hydrogen Implanted Silicon [Articolo su rivista]
B., Pivac; P., Dub; Ek, ; S., Bernstorff; Corni, Federico; Tonini, Rita
abstract

The grazing incidence small angle X-ray scattering (GISAXS) technique was used to study monocrystalline silicon samples implanted with H-2 ions at an energy of 31 keV and to the dose of 10(16) ions/cm(2). Samples were annealed isochronally at different temperatures. Although the H depth distribution was expected to be smooth initially, nanosized features, like agglomerates of defects, have been detected. Annealing destroys this feature due to the relaxation of defects, i.e. redistribution of vacancies and hydrogen. Above 300degreesC a well defined film with highly correlated borders is formed on the edge of the layer rich in defects, whose thickness is slowly decreasing from 25 to 22 nm with increasing annealing temperature. Moreover, defects as well as hydrogen are migrating towards the surface with increasing annealing temperature, as indicated by the increase in surface roughness.

2004 - Nanovoid formationin helium-implanted single-crystal silicon studied by in situ techniques [Articolo su rivista]
Frabboni, Stefano; Corni, Federico; Nobili, Carlo Emanuele; Tonini, Rita; Ottaviani, Giampiero
abstract

In situ transmission electron microscopy and thermal desorption spectrometry have been employed to observe the evolution of vacancy-type extended defects and the corresponding helium state in helium implanted single crystal silicon during thermal ramping annealing. The structural evolution starting with the formation of a platelike cluster of high pressurized helium bubbles and ending in an empty nanovoid is performed conserving tha total volume of vacancy-type extended defects forming each cluster. Structural adjstements occur by surface diffusion inside each cluster following a migration and coalescence mechanism in presence of high pressure helium for 350°C /T/570°C. A conservative Ostwald ripening is observed for 570/T/700°C in presence of helium desorption.

2004 - Phase formations in Co-Silicon system [Articolo su rivista]
Corni, Federico; Tonini, Rita; Ottaviani, Giampiero; S., Alberici; D., Erbetta; T., Marangon
abstract

Interactions between thin cobalt, 40 nm, and a thick - 250 nm -silicon film were investigated by in situ sheet resistance measurements. Poly and amorphous silicon films, both deposited by CVD, were used. MeV He-4(+) Rutherford Backscattering and X-ray diffraction techniques were used to infer the kinds and thicknesses of the compounds formed. Co2Si and CoSi form, on both silicon substrates, in the same way and in substantial consistency with the data reported in literature. The formation of CoSi2 seems to be nucleation controlled on polysilicon, while on amorphous the formation is controlled by diffusion and no nucleation barrier has been detected. The amorphous silicon remains amorphous during the CoSi2 formation, thus suggesting that the model which attributes the absence of a nucleation barrier to silicon crystallization does not hold. (C) 2004 Elsevier B.V. All rights reserved.

2004 - Porosity in low dielectric constant SiOCH films depth profiled by positron annihilation spectroscopy [Articolo su rivista]
R. S., Brusa; M., Spagolla; K. G., Karwasz; A., Zecca; Ottaviani, Giampiero; Corni, Federico; M., Bacchetta; E., Carollo
abstract

The 3-gamma annihilation of orthopositronium and the Doppler broadening of the positron annihilation line have been measured by implanting low energy positrons in low dielectric constant (low-k) SiOCH films. The evolution and stability of film porosity with thermal treatments in the 400–900 °C temperature range has been studied. The films have been produced by plasma enhanced chemical vapor deposition and after annealing in N2 atmospheres at 480 °C have been treated in N2 + He plasma. The minimum free volume of the pores in the as-produced samples has been estimated to correspond to that of a sphere with radius r = 0.6 nm. The treatment in the N2 plasma was found to seal the pores up to 45 nm depth. Both the composition of the films (as obtained by Rutherford backscattering spectroscopy and elastic recoil detection analysis) and the chemical environment of the pores probed by positrons were found to be very stable up to 600 °C thermal treatment. Above such a temperature a reduction of the hydrogen content accompanied by a change in the structure and in the chemical environment of the pores has been observed. In the samples thermal treated at 800–900 °C, the positronium formation is reduced by one-third respect with the as produced sample. In the annealed and as-produced films, a natural aging of 30 days in air was enough to contaminate the porosity, as pointed out by a strong reduction of the 3 annihilations. The effect of contamination and the distribution of the pores were completely recovered after a thermal treatment at 400 °C. Artificial aging of SiOCH films in controlled atmospheres of H2, O2, H2O has shown that H2O is the more efficient contaminant in reducing the effective volume of the pores.

2004 - Sperimentazione incrociata di materiali per la formazione insegnanti a Udine, Modena e Bolzano sulla meccanica [Capitolo/Saggio]
Corni, Federico; M., Michelini; L., Santi; A., Stefanel
abstract

Presso le SSIS di Udine, Modena e Bolzano sono state condotte attività all'interno delle sperimentazioni incrociate dei materiali del sottoprogetto FORM di FFC (MURST 2002-2003) riguardante la formazione insegnanti, in particolare il modulo di intervento formativo sulla cinematica predisposto dall'unità di ricerca di Napoli.

2004 - Strategie di formazione iniziale degli insegnanti: una ricerca coordinata in un modulo di intervento formativo a Reggio Emilia e Udine [Capitolo/Saggio]
Corni, Federico; Michelini, M.; Stefanel, A.
abstract

I problemi di ricerca che ci siamo posti sono i seguenti:1) Quali processi sottendono alla capacità di produrre un’analisi quantitativa della fenomenologia? 2) Quali processi portano ad impadronirsi dell’utilizzo del linguaggio sintetico formale proprio della fisica?3) Quali processi attivano la capacità di organizzare in un quadro organico le conoscenze fisiche?4) Quali processi avviano alla costruzione di un quadro rigoroso che porti sullo stesso piano le conoscenze e le azioni didattiche da svolgere? 5) Quali processi portano a rendere organici i due piani nella realizzazione di proposte didattiche? Abbiamo pertanto individuato strategie differenziate di intervento basate sul mettere in situazione e il coinvolgimento operativo, offrendo strumenti non completamente definiti perché la fase di rielaborazione e progettuale sia essa stessa parte della strategia formativa, integrando formazione professionale e formazione disciplinare. La nostra ricerca riguarda l’analisi dell’impatto di tali strategie in merito ai problemi di ricerca delineati.

2004 - Strategies in formative intervention modules for physics education of primary school teachers: a coordinated research in Reggio Emilia and Udine [Relazione in Atti di Convegno]
Corni, Federico; M., Michelini
abstract

It is nowadays universally recognized that the training of teachers, especially primary school teachers, requires integration of the education in physics and in the psychological and pedagogical fields.Therefore, a cultural background in physics is necessary, as well as knowledge of the conceptual difficulties and of the teaching methods typical of the discipline itself. The formation in a specific field of knowledge has to provide teachers with the capability of transferring concepts.Hence the problem is how to realize a formation supplying educational tools for different situations and contexts, therefore improving teaching competences. Different educational models have been proposed, referring to teaching equipments and operational strategies in meta-cultural, experiential, or situated forms.This work moves from the assumption that pre-service training of teachers requires education in this discipline through the teaching of the discipline itself. This objective can be achieved by means of teaching activities in which the planning as well as the reflection on didactical proposals are an integral part of the teaching process. Moreover, the direct involvement is considered to be effective only when it is operative and tasks and goals to be reached are clearly defined.We have selected different strategies based on such hypotheses and characterized by being set in real situation and by realizing operative involvement. Not completely defined instruments have been offered because the elaboration and the planning phases are considered a part of the intervention therefore integrating professional formation with disciplinary formation.The present research refers to the study of the impact of such a strategy on students of the 2nd year of the Primary Education Sciences Course (PESC). The analysis is centred on the improvement of critical and planning capacities for the construction of professional competences in physics education, with particular care on the planning of single experimental activities, of explorative experimental chains and of maps and conceptual networks for the definition of paths for formal instruments management, either for personal exploration, or for didactical proposal definition.

2004 - Transmission Electron Microscopy study of Helium Implanted Silicon [Relazione in Atti di Convegno]
Frabboni, S.; Corni, F.; Tonini, R.; Nobili, C.; Ottaviani, G.
abstract

The structural evolution of helium related extended defects in silicon, formed after intermediate dose helium implantation and annealing has been investigated. It is found that the highest helium concentration (annealing at 300ºC) is associated to clusters of bubbles arranged in a platelet-like morphology. At 500ºC the helium concentration markedly decreases and clusters of cavities formed by a central, large cavity surrounded by small cavities (planetary like structures) are detected. The thermal treatment at 900ºC accomplishes the complete helium effusion from the sample leaving behind empty cavities i.e. voids.

2004 - Transmission electron microscopy study of blisters in high-temperature annealed He and H co-implanted single-crystal silicon [Articolo su rivista]
Frabboni, Stefano; Gc, Gazzadi; L., Felisari; Tonini, Rita; Corni, Federico; Ottaviani, Giampiero
abstract

Transmission electron microscopy has allowed us to draw the three-dimensional structure of blisters formed after high-temperature annealing of He-H co-implanted silicon by combining the unique capability of site-selective cross sectioning of the focused ion beam with conventional plan view images. It has been shown that blisters are formed by crystalline lamellae strongly bended, plastically deformed, and suspended over buried empty cavities. The volume of the protruding blister surface is almost equal to the buried empty volumes, thus suggesting a mechanism for blister formation based on H and He precipitation and migration of silicon atoms toward the surface.

2003 - Early stages of bubble formation in helium-implated (100) silicon [Articolo su rivista]
B., Pivac; O., Milat; P., Dubcek; S., Bernstorff; Corni, Federico; Nobili, Carlo Emanuele; Tonini, Rita
abstract

Early stages of bubble formation in Czochralski grown, (100)-oriented silicon are investigated by implanting 2 x 10(16) He+ cm(-2) at 20 keV and treating the samples in the temperature range 100-450 degreesC. Elastic recoil detection is used to measure the helium content and depth distribution, while the gas release is studied by thermal desorption spectrometry. To evidence the radiation damage evolution and the defect behavior, the results from Rutherford backscattering spectrometry in channeling conditions, cross sectional transmission electron microscopy, and grazing incidence small angle X-ray scattering are critically analyzed and compared. The study leads to the identification of the steps followed by the defects during annealing and suggests that critical condition for the production of stable bubbles is the presence at low temperature of agglomerates composed of more than four vacancies decorated by helium. This kind of defect offers helium the room necessary to transform into gas phase and confer thermal stability to the bubble embryos.

2003 - GISAXS study of structural relaxation in amorphous silicon [Articolo su rivista]
Dubcek, P; Pivac, B; Bernstorff, S; Tonini, Rita; Corni, Federico; Ottaviani, Giampiero
abstract

The structural changes induced in single crystal silicon implanted with silicon ions above the amorphisation threshold were studied by Grazing Incidence Small Angle X-ray Scattering technique. Silicon samples were implanted with silicon ions at 30 keV to the dose of 5 x 10(15) atoms/cm(2). A well-defined layer of amorphous silicon, thick about 40 nm was formed below the surface. As implanted samples were subsequently relaxed by thermal annealing at 350 degreesC. The analysis have shown that the amorphous layer exhibits a granular structure that develops with annealing. A model will be presented for the film structure changes obtained by data evaluation based on the distorted wave Born approximation. (C) 2002 Elsevier Science B.V. All rights reserved.

2003 - Grazing incidence small-angle X-ray scattering study of defects in deuterium implanted monocrystalline silicon [Articolo su rivista]
P., Dubcek; B., Pivac; S., Bernstorff; Corni, Federico; Tonini, Rita; Ottaviani, Giampiero
abstract

Grazing incidence small-angle X-ray scattering was used to study monocrystalline silicon samples implanted with deuterium ions at an energy of 24 keV and to the dose of 2 x 10(16) ions/cm(2). Samples were annealed isochronally at different temperatures in the range from 393 to 973 K. Due to the relaxation of the defects structures, i.e. redistribution of vacancies and deuterium, strong particle like contribution is observed in addition to the rough surface scattering, already at 393 K annealing. During the annealing, this particles (agglomerations of vacancies) are gradually dissolved till 623 K annealing temperature. Another agglomeration mechanism takes over at about 773 K when a different type of particle growth is observed, and these are dissolved again at about 973 K. The sizes of detected particles are in 2-3 nm range. Also, the interference type of scattering from a film of about 30 nm thickness (the top layer, mostly unaffected by implantation) is observed. This film is gradually getting thinner with the increasing annealing temperature, due to the redistribution of the defects and the structure relaxation.

2002 - A resource environment to learn optical polarization [Relazione in Atti di Convegno]
Cobal, M; Corni, Federico; Michelini, M; Santi, L; Stefanel, A.
abstract

The applications of optical polarization are countless and they offer a window on the relationship, of great social interest, between science and technology. The main phenomenology of light polarization is simple and well-known: it is suitable to organize interesting experimental activities with common materials and with on-line sensors, giving the opportunity to work at different learning levels. The properties of polarization are suitable to constitute a special conceptual link for the introduction of quantum mechanics into the secondary school curriculum and therefore have a peculiar role from a didactic point of view. In the framework of the Italian national projects “Studiare e Capire in Fisica” (SeCiF) and Cultural Education in Physics (CEP) organized by the seven research units of the universities of Milano-s, Milano-b, Naples, Palermo, Pavia, Turin and Udine, materials have been produced for teachers, studied for a culturally innovative and coherent proposal for physics education. The Udine research unit has produced in this context three environments on the web: the first is on thermal phenomena for primary school level, the second is on physical optics, and the third is on quantum mechanics for secondary school level. The materials offered for physical optics are various in nature: experiments, simulations, measurements with on-line computers, didactic path segments, a deeper analysis and cards for students, documentation of pilot experiments in schools. The main features of the proposal on light polarization are studied to offer polarization as “a cultural buffer” for the conceptual transition from classical to quantum mechanics and, at the same time, can be dealt autonomously with a simple formalism, which uses the vector description of the properties. The possible studies of polarization in different contexts (phenomenological-descriptive, undulatory, quantistic) makes it a very important topic for a conceptual synthesis.

2002 - Curiosity: An interesting classroom discussion: What is the right subject of the photograph? [Articolo su rivista]
Corni, Federico
abstract

A photograph of the light spots of the ecplypse of the August 1999 is an occasion for a discussion about light propagation and the pinhole camera principle.

2002 - DLTS and EPR study of defects in H implanted silicon [Articolo su rivista]
V., Miksic; B., Pivac; B., Rakvin; H., Zorc; Corni, Federico; Tonini, Rita; Ottaviani, Giampiero
abstract

Single crystal CZ Si samples were implanted with hydrogen ions to the dose of 2E16 He ions/cm(2) at room temperature and subsequently annealed in vacuum in the temperature interval from 100 to 900 degreesC. The aim of the experiment was to determine the conditions for bubble formation within the solid film, which may have important technological application. Defects produced in such samples were studied by deep-level transient spectroscopy (DLTS) and electron paramagnetic resonance (EPR) spectroscopy. It is shown that high dose hydrogen implantation produces vacancy-related and silicon selfinterstitial clusters. The latter are thought to be responsible for the formation of the weak displacement field. The annealing at higher temperatures creates multivacancy-related clusters responsible for the strong displacement field formation. (C) 2002 Elsevier Science B.V. All rights reserved.

2002 - Damage evolution in helium-hydrogen co-implanted (100) silicon [Articolo su rivista]
Tonini, Rita; Corni, Federico; Nobili, Carlo Emanuele; Ottaviani, Giampiero; Cazzaniga, F; Queirolo, G.
abstract

The modifications induced in single-crystal silicon by helium and hydrogen complantation have been investigated as a function of isochronal heat treatments in the 100-900 degreesC temperature range. 30 keV helium ions were implanted into (100) p-type silicon wafer held at RT with a dose Of 1x10(16) cm(-2); Successively 1x10(16) cm(-2) hydrogen ions were implanted at 24 keV. Various analytical techniques have been used to characterize the in-depth samples: 2 MeV He-4(+) backscattering in channeling conditions (RBS-channeling) to detect damage distribution; elastic recoil detection (ERD) technique with 8 MeV N-15(++) and 2 MeV He-4(+) to measure the helium and hydrogen concentration; cross sectional transmission electron microscopy (XTEM) analysis to characterize the distribution of the defects. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) were used to analyze the surface morphology. According to the backscattering-channeling data two kinds of damage are present: one, damage A, located in a narrow region at a depth corresponding to helium and hydrogen mean projected range and another one, damage B, located from 270 nm to the sample surface. Damage A increases up to 400 degreesC and at higher temperatures tends to disappear. Damage B reaches a maximum after 500 degreesC and stays constant at higher temperatures. Above 500 degreesC the sample surface exhibits blistering and exfoliation phenomena. The area fraction covered by the blisters is proportional to the dechanneling signal caused by damage B. Above 700 degreesC helium and hydrogen are completely desorbed. The presence of blisters and of the related dechanneling signal indicate that silicon is plastically deformed.

2002 - Developing students competencies by means of simulation: use of a research tool for understanding ion-matter interaction in solid state physics [Relazione in Atti di Convegno]
Corni, Federico
abstract

The TRIM simulation code for ion-matter interaction studies is introduced as a didactical tool for secondary school

2002 - In-situ time-resolved reflectivity: a technique useful to investigate solid-state transformations [Articolo su rivista]
Corni, Federico; Tonini, Rita; Pontiroli, A; Pavia, G; Queirolo, G; Zonca, R.
abstract

Solid-state transformations occurring in thin films can be studied by directing a laser beam on to the sample surface and measuring the reflected intensity by means of a photodiode. The technique, called Time-Resolved Reflectivity, is an in-situ technique very fast and simple. Under proper conditions, it allows the entire evolution of a transformation to be followed while it occurs during a thermal treatment, allowing the kinetics of the process to be studied. In this work we present a method and some criteria to extract physical information on layered samples interesting for the microelectronic industry. The surface reflectivity depends on the refractive indices (wavelength dependent) of the materials employed and on the thicknesses of the layers. The results extracted from the raw reflectivity data (obtained with a conventional He-Ne 632.8 nm laser) by means of few simple assumptions, are discussed and compared to those obtained with more conventional, but in most cases, destructive and ex-situ techniques. (C) 2002 Elsevier Science B.V. All rights reserved.

2002 - Reply to comments on 'EPR study of He-implanted Si' by P. Pivac, B. Rakvin, R. Tonini, F. Corni, G. Ottaizani, Published in Mater. Sci. Eng. B73 (2000) 60-63 - Written by M. Kakazey, M. Vlasova, and J.G. Gonzalez-Rodriguez - Reply to discussion [Articolo su rivista]
Pivac, B; Rakvin, B; Tonini, Rita; Corni, Federico; Ottaviani, Giampiero
abstract

Reply to comments on 'EPR study of He-implanted Si' by P. Pivac, B. Rakvin, R. Tonini, F. Corni, G. Ottaizani, Published in Mater. Sci. Eng. B73 (2000) 60-63 - Written by M. Kakazey, M. Vlasova, and J.G. Gonzalez-Rodriguez - Reply to discussion

2002 - Some aspects of blistering and exfoliation of helium-hydrogen coimplanted (100) silicon [Articolo su rivista]
Corni, Federico; Tonini, Rita
abstract

A Si(He,H) system, produced by ion implantation and suitable for SOI fabrication, is studied during and after the thermal treatment which induces surface blistering and exfoliation. The attention is focused on the influence of storage time between the implantation stage and the annealing stage, since it is expected that even at low temperatures the phenomena taking part in the blistering and exfoliation process are active. Three different storage environments are selected: (1) liquid nitrogen, (2) room temperature and (3) 100 °C in air. The main result is that long time sample storage has the effect of decrease the exfoliation efficiency. Moreover, optimum conditions for exfoliation are met at storage time around 24 h at 100 °C, where the maximum fraction (1) of the sample surface (about 16%) results exfoliated and (2) of He atoms (about 80%) are desorbed. The discussion evidences that He desorbtion during annealing and exfoliation efficiency are strictly correlated. Moreover, a phenomenological model explaining the observed storage effect is sketched, deduced from the present knowledge of the Si(H), Si(He) and Si(He,H) systems.

2002 - Thinking on vectors and formal description of the light polarization for a new educational approach [Relazione in Atti di Convegno]
Cobal, M; Michelini, M; Corni, Federico
abstract

The vector approach to light polarization is introduced for physics education purposes

2001 - Helium/deuterium co-implanted silicon – a thermal desorption spectrometry investigation [Articolo su rivista]
Corni, Federico; Nobili, Carlo Emanuele; Tonini, Rita; Ottaviani, Giampiero; Tonelli, Massimo
abstract

Thermal desorption spectrometry has been applied to investigate the blistering and exfoliation phenomena which occur at the surface of a p-type (100) silicon wafer coimplanted with helium and deuterium. During the heat treatments in linear temperature ramp, an explosive emission of both gases occurs. The phenomenon is kinetically controlled with an effective activation energy of 1.3±0.2 eV. In addition, the desorption spectra present a second contribution, attributed to deuterium emission from buried cavities. Also in this case, the process is kinetically controlled with an effective activation energy of 1.9±0.3 eV. Thermal desorption spectrometry is a suitable technique to have information about various phenomena which occur during blistering and exfoliation.

2000 - EPR study of He-implanted Si [Articolo su rivista]
Pivac, B; Rakvin, B; Tonini, Rita; Corni, Federico; Ottaviani, Giampiero
abstract

Electron paramagnetic resonance has been used to study the influence of thermal treatments on defect evolution in helium-implanted Czochralski single-crystal silicon. It is shown that the thermal treatment induces helium migration and capturing by vacancy clusters that transform into pressurized bubbles. Such transformation produces a strain field, which in turn affects the dangling bond's lineshape in its vicinity. It is shown that the strain field causes asymmetry of dangling bond lineshape that is proportional to the strain field. This selects the electron paramagnetic resonance as a convenient technique For the monitoring of the early phases of bubble formation. (C) 2000 Elsevier Science S.A. All rights reserved.

2000 - Electron paramagnetic resonance study of S2 defects in Hydrogen implanted Silicon [Articolo su rivista]
B., Rakvin; B., Pivac; Tonini, Rita; Corni, Federico; Ottaviani, Giampiero
abstract

Electron paramagnetic resonance spectra of S2 paramagnetic center in Float zone silicon (FZ-Si) and Czochralski silicon (CZ-Si) produced by H2 ion-implantation and by subsequent annealing have been studied. At room temperature the spectrum exhibits an isotropic line g 2X0066 0X0002, which, then broadens and transforms in a complex spec- trum at 120 K. This complex spectrum can be decomposed into isotropic and anisotropic component. The relative concentration of anisotropic component is larger in CZ-Si and smaller in FZ-Si than the respective isotropic compo- nent. The g tensor evaluated from the anisotropic component at 120 K shows that the spectrum originated from the center with trigonal symmetry. The involvement of hydrogen and oxygen atoms in the center has been discussed. It is suggested that the S2 center is developed in the multi-vacancy defect containing oxygen and hydrogen atoms. From reversible thermal eect of the linewidth narrowing the motional properties of the dangling bond in the S2 center is described by the activation energy of 0.03 eV. Ó 2000 Elsevier Science B.V. All rights reserved.

2000 - Evolution of vacancy-like defects in He-implanted (100) Si studied by thermal desorption spectrometry [Articolo su rivista]
Corni, Federico; G., Calzolari; Gambetta, Francesca; Nobili, Carlo Emanuele; Tonini, Rita; Zapparoli, Mauro
abstract

hermal desorption spectrometry (TDS) has been applied to investigate the thermal evolution of vacancy-like defects in helium-implanted (100) silicon samples with a dose of 2x1016 cm-2 at 20 keV. The measured spectra present features which can be interpreted as fingerprints of the modifications occurring in the sample. The defects that are recognized which affect the desorption are: thermally unstable helium-vacancy complexes, pressurized gas bubbles organized in planar structures (cracks) and thermally stable cavities. The attribution is supported by the results obtained by complementary techniques, such elastic recoil detection, channeling Rutherford backscattering spectrometry, cross sectional transmission electron microscopy and positron annihilation spectroscopy which have been employed on isothermally pre-annealed samples in the range 100-800oC

2000 - Formation of vacancy clusters and cavities in He-implanted silicon studied by slow-positron annihilation spectroscopy [Articolo su rivista]
R. S., Brusa; G. P., Karwasz; N., Tiengo; A., Zecca; Corni, Federico; Tonini, Rita; Ottaviani, Giampiero
abstract

The depth profile of open volume defects has been measured in Si implanted with He at an energy of 20 keV, by means of a slow-positron beam and the Doppler broadening technique. The evolution of defect distributions has been studied as a function of isochronal annealing in two series of samples implanted at the fluence of 5×1015 and 2×1016He cm-2. A fitting procedure has been applied to the experimental data to extract a positron parameter characterizing each open volume defect. The defects have been identified by comparing this parameter with recent theoretical calculations. In as-implanted samples the major part of vacancies and divacancies produced by implantation is passivated by the presence of He. The mean depth of defects as seen by the positron annihilation technique is about five times less than the helium projected range. During the successive isochronal annealing the number of positron traps decreases, then increases and finally, at the highest annealing temperatures, disappears only in the samples implanted at the lowest fluence. A minimum of open volume defects is reached at the annealing temperature of 250°C in both series. The increase of open volume defects at temperatures higher than 250°C is due to the appearance of vacancy clusters of increasing size, with a mean depth distribution that moves towards the He projected range. The appearance of vacancy clusters is strictly related to the out diffusion of He. In the samples implanted at 5×1015cm-2 the vacancy clusters are mainly four vacancy agglomerates stabilized by He related defects. They disappear starting from an annealing temperature of 700°C. In the samples implanted at 2×1016cm-2 and annealed at 850–900°C the vacancy clusters disappear and only a distribution of cavities centered around the He projected range remains. The role of vacancies in the formation of He clusters, which evolve in bubble and then in cavities, is discussed.

2000 - GISAXS study of defects in He implanted silicon [Articolo su rivista]
P., Dubcek; O., Milat; B., Pivac; S., Bernstorff; H., Amenitsch; Tonini, Rita; Corni, Federico; Ottaviani, Giampiero
abstract

The modifications induced in single-crystal silicon by implanted helium have been investigated by grazing incidence small angle X-ray scattering technique. The samples prepared by implanting 2×1016 cm−2 helium ions at 20 keV in silicon wafers held at 77 K were thermally treated for 2 h in the 100–800°C temperature range. It is shown that implantation produced a film with slightly lower density than that of undamaged single crystal silicon. Further thermal treatment caused shrinking of the film leaving well ordered subsurface layer and damaged film below. Upon annealing at 600°C this structure apparently disappear, to be formed again upon annealing at 800°C.

2000 - Hydrogen and helium bubbles in silicon [Articolo su rivista]
G. F., Cerofolini; Corni, Federico; Frabboni, Stefano; Nobili, Carlo Emanuele; Ottaviani, Giampiero; Tonini, Rita
abstract

Hydrogen is a quite common impurity in semiconductor-silicon technology: it is unintentionally but unavoidably added to the silicon after crystal growth during wafer processing, and continues to be present during wet oxidation, film depositions, etching and annealing steps. The effects of hydrogen in single crystal silicon at low concentration have been the subject of many papers, books and conference proceedings. Much less considered is the case of hydrogen at massive concentration. One Anal effect of heavy hydrogen loading is the formation of cavities and bubbles, with size up to 100 nm. Cavities and bubbles are also observed after helium loading by high-fluence ion implantation. This article reviews the basic mechanisms responsible for the formation and growth of such structures in single-crystalline silicon. In particular, starting from the loading (ion implantation) and having in mind the formation of the cavities, this paper will cover: the effects of substrate temperature, the interaction of vacancies and self-interstitials with the impurity, the mechanisms of gas segregation inside the cavities, the pressure which arises because of the segregation and the subsequent displacement field in the crystal, the stability against heat treatments of the gas in the cavities and of the cavities themselves. The understanding of the physical processes should lead to gain more insight in the processes of cleavage of the Si-Si bond and vacancy agglomeration which can induce not only the formation of cavities and bubbles, but also planar cutting or explosion. (C) 2000 Published by Elsevier Science S.A. All rights reserved.

2000 - Large angle convergent beam electron diffraction strain measurements in high dose helium implanted silicon [Articolo su rivista]
Gambetta, Francesca; Frabboni, Stefano; Tonini, Rita; Corni, Federico
abstract

Large angle convergent beam electron diffraction (LACBED) technique has been applied to <110> TEM cross section of silicon samples implanted with 2x1016 cm-2 He ions at an energy of 20 KeV in order to evaluate the stress/strain field in the implanted layer. The stress/strain field depends on the mismatch between the lattice of the silicon substrate and the one of the defective layer which contains clusters of point defects and small He bubbles. Lattice mismatch causes changes in the spacing and inclination of diffraction planes producing a shift and a rotation of diffraction intensity lines (Bragg contours (BC)) visible in LACBED patterns. In particular, when the electron beam is parallel to the rotation axis, the BC simply rotate. This is the case of mismatches observed with (333) BC when the electron beam is incident on the sample along a direction close to <110> zone axis. Measurements show a peak of the stress/strain field (intensity 1.5 GPa) at a depth close to the helium projected range, where small bubbles occasionally form aggregate oriented along <011> direction.

2000 - Thermal desorption spectra from cavities in helium-implanted silicon [Articolo su rivista]
Cerofolini, Gf; Calzolari, G; Corni, Federico; Frabboni, Stefano; Nobili, Carlo Emanuele; Ottaviani, Giampiero; Tonini, Rita
abstract

Thermal desorption spectra at constant ramp rate have been determined after helium implantation into bare silicon prepared for a large set of experimental conditions. The spectra can phenomenologically be classified as composed by two peaks: the alpha peak, centered on a temperature of 750-800 degrees C with a shoulder extending to lower temperature (down to 550 degrees C), and the beta peak, centered on a lower temperature depending on the implantation-annealing conditions. The alpha peak is attributed to the emission from cavities, while the beta peak is attributed to the emission from vacancylike defects. A detailed theory describing helium effusion from stable cavities as controlled by the interatomic helium-helium potential is proposed and found to reproduce accurately most of the alpha peaks. The postimplantation of hydrogen into samples displaying a pure beta emission results in an alpha peak which can be described by the same model as above provided that the cavities are unstable and shrink during desorption in such a way as to maintain constant the concentration of contained helium.

2000 - Ultradense gas bubbles in Hydrogen- or Helium-implanted (or co-implanted) Silicon [Articolo su rivista]
Cerofolini, G. F.; Calzolari, G.; Corni, Federico; Nobili, Carlo Emanuele; Ottaviani, Giampiero; Tonini, Rita
abstract

Ultradense gas bubbles in Hydrogen- or Helium-implanted (or co-implanted) Silicon

1999 - He-implantation induced defects in Si studied by slow positron annihilation spectroscopy [Articolo su rivista]
Brusa, Rs; Karwasz, Gp; Tiengo, N; Zecca, A; Corni, Federico; Calzolari, G; Nobili, Carlo Emanuele
abstract

Open volume defect profiles have been obtained by performing Doppler broadening measurements with a slow positron beam on p-type Si samples implanted near liquid nitrogen temperature with He ions at 20 keV and at 5 x 10(15) and 2 x 10(16) cm(-2) fluence. The evolution of the defect profiles was studied as a function of isothermal annealing at 250 degrees C. The fraction of released He was measured by thermal programmed desorption. The defects could be identified as a coexistence of monovacancies stabilized by He-related defects and divacancies. The number of defects decreases for annealing time of a few minutes, then increases at longer annealing times. The mean depth of the defect profiles in the as-implanted samples was found to be very near the surface. After annealing, the mean depth increases to less than one half of the projected He range. This complex dynamics has been interpreted as due to passivation of vacancies by He during the implantation process and the first annealing step when no appreciable He is lost, and to subsequent depassivation during He desorption. (C) 1999 American Institute of Physics. [S0021-8979(99)02103-9].

1999 - Helium-implanted silicon: A study of bubble precursors [Articolo su rivista]
Corni, Federico; Calzolari, G; Frabboni, Stefano; Nobili, Carlo Emanuele; Ottaviani, Giampiero; Tonini, Rita; Cerofolini, Gf; Leone, D; Servidori, M; Brusa, Rs; Karwasz, Gp; Tiengo, N; Zecca, A.
abstract

The interaction of helium atoms with the radiation damage imparted to (100) silicon single crystal by He+ implantation at 5 x 10(15) cm(-2), 20 keV, and liquid-nitrogen temperature is investigated by means of various complementary techniques during and after thermal treatments. Thermal programmed desorption was used to study the dissociation kinetics of helium from the defects and to plan suitable heat treatments for the other techniques. The helium profiles were determined by 8 MeV N-15(2+) elastic recoil detection, quantitative data on damage were obtained by channeling Rutherford backscattering spectrometry, double crystal x-ray diffraction, and positron annihilation spectroscopy. Isothermal treatments at 250 degrees C produce first helium redistribution and trapping in vacancy-like defects, rather than helium desorption from traps. The process is thermally activated with an effective activation energy, dispersed in a band from 1.1 to about 1.7 eV. For higher temperature treatments (2 h at 500 degrees C) the traps are almost emptied and at 700 degrees C all vacancy-like defects are annealed out. No bubbles or voids are observed by transmission electron microscopy, either in the as-implanted or in annealed samples. (C) 1999 American Institute of Physics. [S0021-8979(99)00903-2].

1999 - Pre-cavities defect distribution in He implanted silicon studied by slow positron beam [Articolo su rivista]
Brusa, Rs; Karwasz, Gp; Zecca, A; Corni, Federico; Tonini, Rita; Ottaviani, Giampiero
abstract

Several techniques were applied to study distributions of point defects created after He implantation in Si at an energy of 20 keV. The evolution of the defect distributions as a function of isocronal thermal anneling was studied in the 150-900 degrees C temperature range. In particular Doppler-broadening measurements with a slow positron beam were performed to gain information on open volume defects precursors of the cavities that are formed in He implanted silicon after thermal treatment. Profiles of displaced Si atoms, He, and vacancies are presented for the meaningful thermal treatments, and discussed.

1999 - Una sperimentazione di ricerca sull’impiego delle nuove tecnologie nella didattica della fisica per il tema delle oscillazioni meccaniche [Articolo su rivista]
AIELLO NICOSIA M., L; Balzano, E; Bergomi, N; Borghi, L; Giordano, E; Capocchiani, V; Corni, Federico; DE AMBROSIS, A; Marioni, C; Mascheretti, P; Mazzega, Ezio; Michelini, Marisa; Robutti, O; Santi, L; Sassi, E; SPERANDEO MINEO R., M; Viglietta, L; Violino, P.
abstract

Una sperimentazione di ricerca sull’impiego delle nuove tecnologie nella didattica della fisica per il tema delle oscillazioni meccaniche

1999 - Vacancy-gettering in silicon: Cavities and helium-implantation [Articolo su rivista]
Corni, Federico; Tonini, Rita; Frabboni, Stefano; Nobili, Carlo Emanuele; Calzolari, G; Masetti, S; Tamarozzi, P; Pavia, G; Cerofolini, Gf
abstract

Cavities in single crystalline silicon are shown to act as gettering centers for the vacancies produced during an ion implantation process: the effect of the gettering is observed as an increase of their total volume. Helium implantation at 20 keV with a dose of 2 x 10(16) cm(-2) plus a heat treatment at 850 degrees C for 3 hours produces the cavities; vacancies are supplied by a subsequent 0.8 x 10(16) cm(-2) helium implant. In this case the vacancy-gettering efficiency, i.e. average increase of vacancies involved in stable voids per helium ion, is found to be 0.53 vacancies ion(-1); about 4 times more compared to the case when the same 0.8 x 10(16) cm(-2) implant is performed on a virgin crystal. A further effect is the peculiar helium behavior which acts as a stabilizer of the vacancies produced during the implantation. The differential vacancy-gettering efficiency is found to increase with the helium dose: about 0.13 vacancies ion(-1) at 0.8 x 10(16) cm(-2), 0.4 vacancies ion(-1) at 2 x 10(16) cm(-2), and 3.8 vacancies ion(-1) at 2.8 x 10(16) cm(-2) .

1998 - Electron paramagnetic resonance evidence for reversible transformation of thermal donor into shallow donor-type center in hydrogen-implanted silicon [Articolo su rivista]
Rakvin, B; Pivac, B; Tonini, Rita; Corni, Federico; Ottaviani, Giampiero
abstract

Electron paramagnetic resonance spectrum of the proton-related thermal donor (TD) assigned as NL8 paramagnetic center has been detected at 110 K after heat treatment of the hydrogen-implanted Czochralski-Si at 773 K. The effect of temperature on reversible transformations of the anisotropic spectrum of NL8 center into the isotropic singlet line was studied in the temperature region from 110 to 240 K. The analysis of the singlet provides an evidence that this signal originates from the proton- related shallow donor type at g = 1.9987. The changes in the linewidth have been used to evaluate the parameters [1/tau = 0.66 x 10(12) exp(-Delta E/kT); Delta E = 169 meV] for thermally activated electron emission to the conduction band from the second donor state of the NL8 center. These results represent direct experimental evidence of reversible transformation of the TD+ charged center into the shallow donor-type center. (C) 1998 American Institute of Physics. [S0003-6951(98)01548-4].

1998 - Growth kinetics of a displacement field in hydrogen implanted single crystalline silicon [Articolo su rivista]
D., Bisero; Corni, Federico; Frabboni, Stefano; Tonini, Rita; Ottaviani, Giampiero; R., Balboni
abstract

The growth of a displacement field in single crystal silicon resulting from high dose hydrogen implantation and subsequent heat treatments has been investigated by MeV He-4(+) Rutherford backscattering in channeling conditions, double crystal x-ray diffraction, and transmission electron microscopy. The results obtained in samples annealed for various times in the temperature range 220-350 degrees C have been explained in terms of a kinetic model which assumes the formation of clusters of hydrogen molecules. The growth of the displacement field is thermally activated with an activation energy of 0.50+/-0.05 eV, suggesting that the limiting process could be the release of hydrogen atoms bounded to defects created by ion implantation.

1998 - High-dose helium-implanted single-crystal silicon: Annealing behavior [Articolo su rivista]
Tonini, Rita; Corni, Federico; Frabboni, Stefano; Ottaviani, Giampiero; Cerofolini, G. F.
abstract

The modifications induced in single-crystal silicon by implanted helium have been investigated by ion beam techniques. The damage has been detected by 2 MeV 4He+ backscattering in channeling conditions and the helium in-depth distribution by 7 and 8 MeV 15N++ elastic recoil scattering. The samples prepared by implanting 2×1016 cm−2 helium ions at 20 keV in silicon wafers held either at 77 K (LNT sample) or at 300 K (RT sample) have been heat treated for 2 h in the 100–800 °C temperature range. In the as-implanted LNT sample the damage maximum is at 130±20 nm and shifts in-depth to 180±10 nm after annealing at 200 °C, in the as-implanted RT sample, the damage maximum is already located at 180±10 nm. In the 250–500 °C temperature range, the LNT and RT samples follow the same annealing path with only slight differences in the temperature values; in both cases, the dechanneling signal increases and reaches a maximum value of nonregistered silicon atoms of 2.2–2.5×1022 at/cm3. In the same temperature range, the helium signal becomes narrower, builds up in a region centered on 220±20 nm and no appreciable loss of helium can be detected. The growth of the damage is consistent with the creation of cracks and a etherogenous distribution of bubbles filled with high pressure helium which stress the lattice; for the channeling Rutherford backscattering technique, their action is similar to silicon interstitials. At temperatures above 500 °C, helium is released from the samples; this process is associated with a decrease of the damage and the formation and increase in size of voids. At 900 °C empty voids with a diameter around 20 nm are found.

1998 - Problem solving activities with hands on experiments for orienting in science [Relazione in Atti di Convegno]
Bosio, S; Capocchiani, V; Michelini, M; Vogrig, F; Corni, Federico
abstract

Experiments are presented in the form of problem solving

1998 - The effect of biaxial stress on the solid phase epitaxial crystallization of GexSi((1-x)) films [Articolo su rivista]
Corni, Federico; Frabboni, Stefano; Tonini, Rita; Leone, D; de Boer, W; Gasparotto, A.
abstract

Two fully-strained, Si rich, GexSi((1-x)) alloys deposited on (100) Si by CVD were amorphized including part of the substrate. and recrystallized at different temperatures in the range 500-620 degrees C. The amorphous-crystal interfaces remain flat during crystallization, and the films grow coherently with the substrate producing crystalline, defect-free, strained heteroepitaxial layers. The kinetics of the process, compared with literature data of the corresponding relaxed alloys, are affected by the presence of the in-plane stress at the interface, resulting in a decrease of the velocity, in quantitative agreement with the predictions of the activation strain model in the case of biaxial stress.

1997 - Evolution of defect profiles in He-implanted silicon studied by slow positrons [Relazione in Atti di Convegno]
Brusa, Rs; Karwasz, Gp; Tiengo, N; Zecca, A; Corni, Federico; Nobili, Carlo Emanuele; Ottaviani, Giampiero; Tonini, Rita
abstract

He implanted in silicon forms clusters and then out-diffuses from the surface of the crystal when the implanted silicon samples are annealed from 200 to 700 degrees C, Evaporated He leaves empty voids in the Si crystal. The dimension of the voids and the dynamics of the void formation are strictly related to the He dose. A variable-energy positron beam has been used for monitoring the formation and the evolution of the void distribution in p-type (100) Si (1.7-2.4 Omega cm), created by implantation at 77 K of He ions ( 5x10(15) ions/cm(2)) at 20 keV. The samples were treated at 250 degrees C for different annealing times. Thermal desorption (TD) measurements of He are also presented.

1997 - Helium in silicon: Thermal-desorption investigation of bubble precursors [Articolo su rivista]
Corni, Federico; Nobili, Carlo Emanuele; Ottaviani, Giampiero; Tonini, Rita; Calzolari, G; Cerofolini, Gf; Queirolo, G.
abstract

Thermal desorption measurements are performed on (100)-oriented p-type Si wafers implanted with He ions at 20 keV. The doses have been selected in order to produce crystal damage avoiding the formation of detectable bubbles. The He effusion kinetics, studied both in isothermal and in constant heating rate conditions, exhibit effective activation energy heterogeneity indicating the presence of various kinds of traps, precursor of the bubbles. The energy distribution results peaked at about 1.1 eV with an exponential decay towards higher energies and a width of about 0.2 eV. A semiquantitative model, based on the present knowledge about the Si:He system, is proposed, that accounts for He filled nanoblisters formation through interstitial He clustering and precipitation. The observed energy heterogeneity is ascribed to variations of the He solution energy from these cavities due to He-He and He-wall interactions.

1997 - Infrared light emission due to radiation damage in crystalline silicon [Articolo su rivista]
Bisero, D; Corni, Federico; Ottaviani, Giampiero; Tonini, Rita; Pavesi, L.
abstract

We have observed a set of broad luminescence bands between 1.07 and 0.85 eV, in He-implanted Si annealed in vacuum. These emissions are very similar to those of H-implanted and annealed Si, demonstrated by different groups in last years, in which H was believed to play a fundamental role. A comparison between the photoluminescence of He-implanted Si and of H-implanted Si, has allowed to conclude that the infrared photoluminescence of the Si:H system does not depend on H presence, but must be completely ascribed to the damage produced by the bombardment of Si with light ions. (C) 1997 Published by Elsevier Science Ltd. All rights reserved.

1997 - Infrared study of Si-rich silicon oxide films deposited by plasma-enhanced chemical vapor deposition [Articolo su rivista]
Sassella, A; Borghesi, A; Corni, Federico; Monelli, A; Ottaviani, Giampiero; Tonini, Rita; Pivac, B; Bacchetta, M; Zanotti, L.
abstract

A single chamber system for plasma-enhanced chemical vapor deposition was employed to deposit different films of SiOx:N,H with 0.85 less than or equal to x less than or equal to 1.91, which are studied here by Fourier transform infrared transmission spectroscopy. The sample composition was determined by Rutherford backscattering spectrometry, nuclear reaction, and elastic recoil detection analysis. Moreover, physical properties such as thickness uniformity, deposition rate, density, wet and dry etch rates, and stress are determined. A quantitative study of Si-OH, N-H, and Si-H bonds was performed and interpreted on the basis of the random bonding model; in addition, the presence of NH2, Si-O-Si, H2SiO2, and Si-N groups was detected. The effect of sample annealing at 600 and 900 degrees C was studied and two species of Si-H bonds were identified, one more stable and the other one easily releasable. A reordering effect of annealing was also detected as-a reduction of the amorphous network stress and as the increase of the bond angle in the Si-O-Si groups up to the value typical of thermal SiO2.

1997 - Photoluminescence characterization of SiGe QW grown by MBE [Articolo su rivista]
De Padova, P; Perfetti, P; Felici, R; Priori, S; Quaresima, C; Pizzoferrato, R; Casalboni, M; Prosposito, P; Corni, Federico; Tonini, Rita; Grilli, A; Raco, A.
abstract

Photoluminescence (PL) emission spectra have been carried out on a partially relaxed Si/Si1-xGex/Si quantum well (QW) grown by solid-source MBE at a nominal composition of x = 17%, The results are discussed in terms of the film morphology, as derived from structural techniques (SEM, RHEED, RES and XRD): especially as regards the presence of a high density of dots-like 3D structures. PL spectra show an intense brood band, attributed to excitonic recombinations at interstitial plateletes in the dots, with smaller X-NP and X-TO excitonic lines due to phonon-resolved interband transitions originated from the strained epitaxyal layer grown before the dot formation.

1997 - Positron annihilation studies of silicon-rich SiO2 produced by high dose ion implantation [Articolo su rivista]
G., Ghislotti; B., Nielsen; P., Asoka Kumar; K. G., Lynn; L. F., Di Mauro; Corni, Federico; Tonini, Rita
abstract

PAS is used to study Si-rich SiO2 samples prepared by implantation of Si (160 keV) ions at doses in the range 3e16-3e17 and consequent thermal annealing at high temperature (up to 1100 oC)....

1997 - Radiation enhanced transport of hydrogen in SiO2 [Articolo su rivista]
Corni, Federico; Monelli, A; Ottaviani, Giampiero; Tonini, Rita; Queirolo, G; Zanotti, L.
abstract

2.2 MeV He-4(+) and 7 MeV N-15(2+) ion beams have been used to investigate, by in situ measurements, the hydrogen desorption processes in SiO2 thin films deposited by plasma enhanced chemical vapor deposition (PECVD). An effective cross-section of 3 x 10(-16) cm(2) for He and 17 x 10(-16) cm(2) for N has been measured for the ion-thin-film interaction phenomena, The structure crystalline silicon/thermally grown SiO2/PECVD film has also been investigated for the hydrogen radiation-enhanced diffusion in thermally grown SiO2. The data are consistent with a diffusion process with a diffusion coefficient of (5.0 +/- 0.5) x 10(-26) cm(2)/ion from a constant source at a concentration C-0 = (2.5 +/- 0.2) x 10(21) at/cm(3).

1997 - Teaching mechanical oscillations using an integrated curriculum [Articolo su rivista]
AIELLO NICOSIA, M. L.; Balzano, E.; Bergomi, N.; Borghi, L.; Giordano, E.; Capocchiani, V.; Corni, Federico; DE AMBROSIS, A.; Marioni, C.; Mascheretti, P.; Mazzega, Ezio; Michelini, Marisa; Robutti, O.; Santi, L.; Sassi, E.; SPERANDEO MINEO, R. M.; Viglietta, L.; Vegni, G.; Violino, P.
abstract

A set of teaching materials dealing with harmonic oscillations was developed as part of a research project investigating the influence of different pedagogical tools on physics learning. The materials incorporate simulation software and laboratory activities associated with Teacher and Student Units. The project involved research groups at seven Italian universities and the materials have been trialled in high schools nation‐wide. This paper describes the experimental protocol for the use of these materials in pilot classes and the evaluation of student learning and teacher training results. The intervention was found to improve physics education at school praxis level and to promote understanding of the content area as well as appreciation of the role of experiments and simulations in the construction of scientific knowledge

1997 - Visible light emission from silicon implanted and annealed SiO2 layers [Articolo su rivista]
Ghislotti, G; Nielsen, B; Asokakumar, P; Lynn, Kg; Dimauro, Lf; Bottani, Ce; Corni, Federico; Tonini, Rita; Ottaviani, Giampiero
abstract

Silicon implanted and annealed SiO2 layers are studied usin g photoluminescence (PL) and positron annihilation spectroscopy (PAS). Two PL emission bands are observed. a band centered at 560 nm is present in as-implanted samples and it is still observed after 1000 degrees C annealing. The emission time is fast. A second band centered at 780 nm is detected after 1000 degrees C annealing. The intensity of the 780 nm band further increased when hydrogen annealing was performed. The emission time is long (1 mu s to 0.2 ms). PAS results show that defects produced by implantation anneal at 600 degrees C. Based on the annealing behavior and on the emission times, the origin of the two bands is discussed.

1996 - A Problem for educational research: The updating of the curriculum [Relazione in Atti di Convegno]
Corni, Federico; Mazzega, Ezio; Ottaviani, Giampiero; Michelini, M; MICHELUTTI G., L; Santi, L.
abstract

Some discussion topics are pointed out for the curriculum updating

1996 - Bandgap widening in quantum sieves [Articolo su rivista]
Cerofolini, Gf; Meda, L; Bisero, D; Corni, Federico; Ottaviani, Giampiero; Tonini, Rita
abstract

Dense distributions of separate insulating regions in silicon may produce Anderson localization and hence a kind of confinement. This weak confinement is expected to be responsible for visible photoluminescence with different features from that observed in porous or nanocrystalline silicon. Dense distributions of separate insulating regions may be produced by ion implantation of a suitable species followed by an appropriate heat treatment. The visible photoluminescence observed in ion-implanted Si:H, Si:O and Si:He is explained in terms of exciton weak confinement.

1996 - Hydrogen determination in Si-rich oxide thin films [Articolo su rivista]
Monelli, A; Corni, Federico; Tonini, Rita; Ferrari, C; Ottaviani, Giampiero; Zanotti, L; Queirolo, G.
abstract

Quantitative in-depth distribution of the elements contained in silicon-rich oxide thin films deposited on single-crystal silicon by low temperature plasma-assisted deposition has been performed by a combination of various MeV ion beam techniques. The quantity of oxygen and nitrogen has been measured by nuclear reactions, the silicon content has been determined by Rutherford backscattering, and elastic recoil detection was used for hydrogen. All the samples contain not only Si and O, but also N and H, which are residuals from the reactions involved in the deposition process. We did find that the MeV beam used in the nuclear techniques can induce a process of hydrogen desorption, which causes the measured H content to be a function of the He dose received by the sample. This phenomenon, not previously reported, must be taken into account to give the comet H content. The study of the kinetics of the He-induced hydrogen desorption has been used to correct the experimental data and to determine the original hydrogen content. The correction factor is in most of the cases close to 2 and outside any experimental error. Moreover the studies of the kinetics give information on the kinds of hydrogen complexes contained in the films. The results suggest that, on the basis of the strength of the binding energies, hydrogen is present in at least two different configurations, weakly and strongly bonded. In the first configuration hydrogen is easily desorbed either under the action of the ion beam or of the heat treatment at 600 degrees C, in the second, hydrogen is lost only after treatment at 900 degrees C.

1996 - Rutherford Backscattering Spectrometry: a technique worth introducing into pedagogy [Relazione in Atti di Convegno]
Corni, Federico; Ottaviani, Giampiero; Michelini, M; MICHELUTTI G., L; Santi, L; Stefanel, A.
abstract

The RBS technique is introduced as source of didactical activities for Secondary School.

1996 - Silicon interstitials generation during the exposure of silicon to hydrogen plasma [Articolo su rivista]
Tonini, Rita; Monelli, A; Corni, Federico; Frabboni, Stefano; Ottaviani, Giampiero; Queirolo, G.
abstract

Interstitials in silicon can be produced by hydrogen ions through chemical action and physical impact. To establish the relative importance of the two processes, wafers of single crystal silicon kept at a temperature of 250 degrees C were exposed to a hydrogen plasma, with and without an accelerating voltage (500 V). As gettering centers interstitial-type dislocation loops were made, before H exposure, by implanting 1.9 x 10(15) at. cm(-2) 110 keV P atoms and annealing at 1000 degrees C for 30 s. The analysis was performed using MeV ion channeling, elastic recoil detection analysis and cross-section transmission electron microscopy. The results suggest that H is captured by the defects: in the case of unbiased plasma, H goes in the region of the extrinsic defects, while in the case of biased plasma, H is trapped near the surface where the defects are produced by the energetic H ions themselves. In both cases the data are consistent with the formation of hydrogen nanoblisters with the subsequent breaking of silicon bonds and injection of silicon interstitials. The migration of interstitials occurs at a temperature as low as 250 degrees C.

1996 - Stress and interface morphology contributions in the crystallization kinetics of a GexSi1-x thin layer on (100)Si [Articolo su rivista]
Corni, Federico; Frabboni, Stefano; Tonini, Rita; Ottaviani, Giampiero; Queirolo, G.
abstract

A study of the solid phase epitaxial growth from amorphous phase of a strained GexSi1-x thin layer made by Ge-74(+) ion implantation of (100) Si is presented. Ge peak concentration is 6.4 at. %. Principally employed techniques are time-resolved reflectivity for crystallization rate measurements and cross sectional transmission electron microscopy (TEM) for interface morphology imaging. The kinetics is heavily affected by the mismatch stress induced by the Ge; the experimental data cannot however be explained considering only the average stress along the amorphous-crystal interface and another mechanism is required. Cross sectional TEM observations of partially crystallized samples reveal the tendency of the interface to roughen with an evolution reflected in the crystallization activation energy Such roughness is assumed to affect the kinetics by locally enhancing the interface stress.

1996 - The concept of the cross section [Relazione in Atti di Convegno]
Corni, Federico; Michelini, M; Santi, L; Soramel, F; Stefanel, A.
abstract

The concept of cross section in introduced as a key concept in various research techniques involving collisions.

1996 - Un’introduzione alla Rutherford Backscattering Spectrometry [Relazione in Atti di Convegno]
Corni, Federico
abstract

Scopo di questo lavoro è quello di fornire materiale di aggiornamento culturale agli insegnanti sulla RBS, più che formulare una proposta didattica sull'argomento. E' infatti competenza degli insegnanti stabilire come e quanto di questi contenuti può entrare a far parte della didattica della fisica o più in generale delle scienze nella scuola secondaria superiore.

1995 - Capire la Time-Resolved Reflectivity: una tecnica di analisi basata sull’interferenza da lamina sottile [Articolo su rivista]
Corni, Federico; Mazzega, Ezio; Michelini, Marisa; Ottaviani, Giampiero
abstract

Misure di riflettività per valutare piccoli spessori

1995 - Hydrogen precipitation in highly oversaturated single-crystalline silicon [Articolo su rivista]
Cerofolini, Gf; Balboni, R; Bisero, D; Corni, Federico; Frabboni, Stefano; Ottaviani, Giampiero; Tonini, Rita; Brusa, Rs; Zecca, A; Ceschini, M; Giebel, G; Pavesi, L.
abstract

A review of high concentration Hydrogen in Silicon is presented.

1995 - Silicon oxynitride study by the tetrahedron model and by spectroscopic ellipsometry [Articolo su rivista]
Sassella, A; Lucarno, P; Borghesi, A; Corni, Federico; Rojas, S; Zanotti, L.
abstract

Silicon oxynitride samples deposited by plasma-enhanced chemical vapour deposition are characterized by different techniques to obtain their stoichiometry and density. From these data and applying the tetrahedron model, the optical functions in the range from 0.23 to 0.90 mu m are calculated and compared with the results of spectroscopic ellipsometry.

1995 - Visible photoluminescence from He‐implanted silicon [Articolo su rivista]
D., Bisero; Corni, Federico; Nobili, Carlo Emanuele; Tonini, Rita; Ottaviani, Giampiero; C., Mazzoleni; L., Pavesi
abstract

Visible photoluminescence has been observed at cryogenic temperatures from crystalline Si bombarded with He and exposed to H either as plasma or gas in the 250-450 degrees C temperature range. The experimental results are consistent with the formation of Si nanoparticles produced by He segregation, which is responsible for exciton localization, and H passivation of the nonradiative recombination centers.

1994 - Recrystallization of strainedlayers with various Gegradients and in the presence of impurities [Articolo su rivista]
Corni, Federico; Tonini, Rita; Balboni, R; Vescan, L.
abstract

The recrystallization of amorphous GexSi1-x thin films on Si with uniform and with increasing Ge content is studied. The amorphous-crystal interface roughness is modified by the presence of C and O impurities before entering the GexSi1-x layer. The crystallization kinetics are heavily affected by the resulting interface morphology. A minimum velocity is found in the region of the impurities where the interface starts to roughen; the strain effect induced by the Ge within the GexSi1-x is overcome and the crystallization proceeds according to kinetics very similar to those for pure Si.

1994 - Visible luminescence from silicon by hydrogen implantation and annealing treatments [Articolo su rivista]
Pavesi, L; Giebel, G; Tonini, Rita; Corni, Federico; Nobili, Carlo Emanuele; Ottaviani, Giampiero
abstract

Luminescence at an energy higher than the Si band-gap energy has been observed following H implantation and annealing treatments of Si samples. This phenomenon is discussed considering the damage caused by the H implantation and its evolution with thermal treatments. No definitive answer on the origin of the luminescence is given but various possible models are proposed.

1993 - A simple on-line system employed in diffraction experiments [Relazione in Atti di Convegno]
Corni, Federico; Mascellani, V; Mazzega, Ezio; Michelini, M; Ottaviani, Giampiero
abstract

The system to allow the measurement of intensity of diffracted light as a function of space is described as well as the experiments that can be done in a secondary school laboratory

1993 - Dilute NiPt alloy interactions with Si [Articolo su rivista]
Corni, Federico; Gregorio, Bg; Ottaviani, Giampiero; Queirolo, G; Follegot, Jp
abstract

The reaction between a dilute Ni95Pt5 alloy and [111]Si has been investigated as a function of the annealing temperature and time, and the film thickness. Contrary to the concentrate alloys the first phase formed is Ni2Si and the growth kinetics in the initial steps are similar to the case of pure Ni. Pt segregates in the alloy and its presence slows down the silicide growth rate suggesting that a new mechanism, namely the release of Ni from the alloy, is competing with the diffusion process in the silicide. In all the cases here considered NiSi starts to form only when an the Ni is reacted, indicating that the Pt never reaches high enough concentrations to inhibit the Ni2Si growth. The further evolution of the system is similar to the ones reported for bilayers and non-dilute alloys. The I-V characteristics measured after annealing give a barrier height of 0.70+/-0.01 eV.

1993 - Giant radiation damage produced by the impact of heavy molecular ions onto silicon single crystal [Articolo su rivista]
Cerofolini, Gf; Bertoni, S; Meda, L; Balboni, R; Corni, Federico; Frabboni, Stefano; Ottaviani, Giampiero; Tonini, Rita; Para, Af
abstract

The giant radiation damage imparted to single-crystalline silicon by the impact of Re2(CO)2+ at 140 keV is studied by conventional and high-resolution transmission electron microscopy. Evidence for damage produced by the correlated motion of the atoms initially forming the molecular ion is presented.

1993 - Il convertitore analogico-digitale come dispositivo di misura nella didattica della fisica [Articolo su rivista]
Corni, Federico
abstract

Convertitore analogico digitale e laboratorio didattico

1993 - Understand Time Resolved Reflectivity by simple experiments [Relazione in Atti di Convegno]
Corni, Federico; Mazzega, Ezio; Michelini, M; Ottaviani, Giampiero
abstract

The Time Resolved Reflectivity technique is introduced through simple laboratory experiments for secondary school

1992 - A fast technique for the quantitative analysis of channeling RBS spectra [Articolo su rivista]
Cerofolini, Gf; Corni, Federico; Ottaviani, Giampiero; Tonini, Rita
abstract

A straightforward method for the analysis of channeling RBS spectra is developed and validated. This method needs a minimum of computational complexity and does not require the a priori knowledge of the location of the scattering centres and of their dechanneling cross section. The method is applied to channeling RBS spectra obtained along the [100] direction in a hydrogen-implanted (100) silicon crystal to verify that the evaluated displaced-atom depth distribution is independent of the probe energy.

1992 - Crystallization kinetics of boron- and germanium-implanted 〈100〉 Si: a balance between doping and strain effects [Articolo su rivista]
Corni, Federico; Tonini, Rita; Ottaviani, Giampiero; Servidori, M; Priolo, F.
abstract

Electrical and strain arguments were used to explain the differences in growth rate observed for silicon solid phase epitaxy in the presence of electrically active dopants and neutral impurities. In the case of dopants, strain effects seem to be absent or at least to play a negligible role, while for neutral impurities strain seems to be very important. The purpose of this work was to study the role of dopants in the presence of intentionally strained silicon films. The studies were performed by comparing the growth rates measured in samples implanted with boron and germanium, and the growth rates obtained in samples implanted with only germanium or only boron. With respect to intrinsic silicon, boron produces a rate enhancement, germanium a decrease and boron-germanium a slight increase. The results are interpreted by taking into account the strain and by assuming that strain and electrical effects are independent.

1992 - HYDROGEN-RELATED COMPLEXES AS THE STRESSING SPECIES IN HIGH-FLUENCE, HYDROGEN-IMPLANTED, SINGLE-CRYSTAL SILICON [Articolo su rivista]
Cerofolini, Gf; Meda, L; Balboni, R; Corni, Federico; Frabboni, Stefano; Ottaviani, Giampiero; Tonini, Rita; Anderle, M; Canteri, R.
abstract

This work is devoted to the characterization of the Si:H system obtained by high-fluence, low-energy, hydrogen implantation into single-crystal silicon. The implanted hydrogen profile and the ones resulting after thermal annealing in the range 100-800-degrees-C are detected by secondary-ion mass spectrometry and elastic-recoil detection analysis. The displacement field in the crystal, measured by channeling Rutherford-backscattering spectrometry, is found to depend on the direct radiation damage, the extended defects formed after ion implantation (revealed by transmission electron microscopy), and the implanted species. The contribution to the displacement field due to hydrogen-related defects has a characteristic reverse annealing in the range 100-400-degrees-C, essentially due to their formation kinetics.

1992 - ION MIXING IN SI/GE LAYERED STRUCTURES [Articolo su rivista]
Zhu, B; Chow, Jt; Xia, W; Lau, Ss; Butz, R; Mantl, S; Corni, Federico; Ottaviani, Giampiero
abstract

Ion mixing of semiconductor layered structures has been found to exhibit a thermally activated regime and an athermal regime, similar to that observed for metal-semiconductor and metal-metal systems. The kinetics of ion mixing in the Si/Ge system were investigated in this work; the emphasis was placed on the effects of impurities and the mismatch strain on the athermal mixing rate. It was found that the presence of H, Au, W, and O does not affect the ion mixing kinetics between Si and Ge. The athermal mixing rate, however, appears to be significantly affected by the mismatch strain in the layered structure. These results indicate that strain energy plays an important role in biasing the random walk process of mixing.

1992 - SEARCH FOR NUCLEAR-REACTIONS PRODUCED BY THE IMPACT OF HEAVY MOLECULAR-IONS ONTO LID [Articolo su rivista]
Cerofolini, Gf; Corni, Federico; Ottaviani, Giampiero; Tonini, Rita
abstract

Preliminary evidence for light element fusions induced by the impact of heavy molecular ions, with mass around 430 a.m.u. (obtained by fragmentation of Re2(CO)10) and energy 140 keV, onto LiD target is presented. The experimental arrangement excludes the impact of fast light particles due to fragmentation inside the acceleration column and supports the idea of a <<new>> underlying physics.

1992 - SOLID-PHASE EPITAXIAL-GROWTH OF GE-SI ALLOYS MADE BY ION-IMPLANTATION [Articolo su rivista]
Corni, Federico; Frabboni, Stefano; Ottaviani, Giampiero; Queirolo, G; Bisero, D; Bresolin, C; Fabbri, R; Servidori, M.
abstract

Solid-phase epitaxial growth was studied in germanium-implanted <100> silicon wafers as a function of germanium fluence, annealing temperature, and time. MeV He Rutherford backscattering in channeling conditions, cross-sectional transmission electron microscopy, double-crystal x-ray diffraction, and secondary-ion mass spectroscopy techniques were used to characterize the samples. At low fluences, up to 1 x 10(15) cm-2 at 130 keV, the crystallization kinetics is similar to that measured on self-amorphized silicon. In the high-dose samples, prepared by multiple implants with a total dose of 3.12 x 10(16) cm-2, the growth rate at fixed temperatures decreases. A comparison with literature data, obtained by similar experiments performed on amorphized uniform GexSi100-x films prepared by molecular-beam epitaxy or chemical-vapor deposition, reveals that the concentration gradient, unavoidable in implanted samples mainly at the end of the ion range region, is strictly connected with the observed decrease.

1991 - EVIDENCE FOR MOLECULAR-HYDROGEN IN SINGLE-CRYSTAL SILICON [Articolo su rivista]
Meda, L; Cerofolini, Gf; Ottaviani, Giampiero; Tonini, Rita; Corni, Federico; Balboni, R; Anderle, M; Canteri, R; Dierckx, R.
abstract

Rutherford backscattering in channeling in combination with elastic recoil detection analysis has been used to study the formation and destruction of hydrogen supermolecular complexes (H2)n formed in single crystal silicon after hydrogen implantation and annealing in the range 150-800-degrees-C. Secondary ion mass spectroscopy has been used to confirm this interpretation by giving direct evidence for H-2. The supermolecular configuration can be interpreted as the nucleus for the formation of bubbles.

1988 - X-ray Absorption Spectroscopy in YBa2Cu3O7-x superconductors with variable oxygen con¬tent [Articolo su rivista]
M., Sacchi; Corni, Federico; G. M., Antonini; CALANDRA BUONAURA, Carlo; F. C., Matacotta; R., Frahm
abstract

We report the results of XANES and EXAFS measurements performed on YBa2Cu3O7–x compounds withx ranging from 0 to 1. Data for Cu and YK-edges are presented and definite trends in the behaviour of the main near edge structures are singled out, which allow to address the question of the Cu and Y oxidation states and to elucidate the role of the chemical environment in determining the shape of the absorption lines. The inter-atomic distances as obtained by EXAFS generally agree with the results of X-ray diffraction data with the exception of the Y–O distances. Possible sources of this discrepancy are indicated.

1987 - Atomic Local Coordinations and Multivalent States in YBa2Cu3O9-δ Superconductors [Articolo su rivista]
G. M., Antonini; CALANDRA BUONAURA, Carlo; Corni, Federico; F. C., Matacotta; M., Sacchi
abstract

EXAFS and XANES spectra at the edges of Cu and Y have been measured in the YBa2Cu3O9-δ(δ 2) superconductor. The oxygen coordination around the two metals is found to generally agree with the model suggested by diffraction experiments, especially as the occurrence of two distinct distances between Cu and O along the perovskite structure c-axis is concerned. Conversely, some evidence is found for a partial occupation of the oxygen sites in the yttrium plane, a result excluded by diffraction experiments. This is better supported by EXAFS spectra at the Y-edge. The XANES spectra of the superconductor are remarkably different from those of Cu oxides suggesting the presence of both divalent and trivalent Cu, in agreement with EXAFS and diffraction results.

1986 - EXAFS investigation of interdiffusive kinetics in CuAu thin films [Articolo su rivista]
Corni, Federico; G. M., Antonini
abstract

Thermal diffusion in a multilayer of Au and Cu thin films is studied by means of EXAFS and the short range order atomic correlation is investigated as a function of the annealing treatment.

Università degli studi di Modena e Reggio Emilia

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