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DAVIDE CASOTTI

Personale TA a tempo determinato-Tesoro
Dipartimento di Ingegneria "Enzo Ferrari"

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Pubblicazioni

2023 - Friction and wear of DLC films deposited on additive manufactured AlSi10Mg: the role of surface finishing [Articolo su rivista]
Salerno, E.; Casotti, D.; Paolicelli, G.; Gualtieri, E.; Ballestrazzi, A.; Gazzadi, G. C.; Bolelli, G.; Lusvarghi, L.; Valeri, S.; Rota, A.
abstract

2022 - Investigation on Sensing Performance of Highly Doped Sb/SnO2 [Articolo su rivista]
Feng, Z.; Gaiardo, A.; Valt, M.; Fabbri, B.; Casotti, D.; Krik, S.; Vanzetti, L.; Della Ciana, M.; Fioravanti, S.; Caramori, S.; Rota, A.; Guidi, V.
abstract

Tin dioxide (SnO2) is the most-used semiconductor for gas sensing applications. However, lack of selectivity and humidity influence limit its potential usage. Antimony (Sb) doped SnO2 showed unique electrical and chemical properties, since the introduction of Sb ions leads to the creation of a new shallow band level and of oxygen vacancies acting as donors in SnO2. Although low-doped SnO2:Sb demonstrated an improvement of the sensing performance compared to pure SnO2, there is a lack of investigation on this material. To fill this gap, we focused this work on the study of gas sensing properties of highly doped SnO2:Sb. Morphology, crystal structure and elemental composition were characterized, highlighting that Sb doping hinders SnO2 grain growth and decreases crystallinity slightly, while lattice parameters expand after the introduction of Sb ions into the SnO2 crystal. XRF and EDS confirmed the high purity of the SnO2:Sb powders, and XPS highlighted a higher Sb concentration compared to XRF and EDS results, due to a partial Sb segregation on superficial layers of Sb/SnO2. Then, the samples were exposed to different gases, highlighting a high selectivity to NO2 with a good sensitivity and a limited influence of humidity. Lastly, an interpretation of the sensing mechanism vs. NO2 was proposed.

2021 - Silicon crystals for steering high-intensity particle beams at ultrahigh-energy accelerators [Articolo su rivista]
Mazzolari, A.; Romagnoni, M.; Bagli, E.; Bandiera, L.; Baricordi, S.; Camattari, R.; Casotti, D.; Tamisari, M.; Sytov, A.; Guidi, V.; Cavoto, G.; Carturan, S. M.; De Salvador, D.; Balbo, A.; Cruciani, G.; Nhi Tran Caliste, Thu; Verbeni, R.; Pastrone, N.; Lanzoni, L.; Rossall, A.; van den Berg, J. A.; Jenkins, R.; Dumas, and P.
abstract

Experimental results and simulation models show that crystals might play a relevant role for the development of new generations of high-energy and high-intensity particle accelerators and might disclose innovative possibilities at existing ones. In this paper we describe the most advanced manufacturing techniques of crystals suitable for operations at ultrahigh energy and ultrahigh intensity particle accelerators, reporting as an example of potential application the collimation of the particle beams circulating in the Large Hadron Collider at CERN, which will be upgraded through the addition of bent crystals in the frame of the High Luminosity Large Hadron Collider project.

2018 - Ageing effects on electrical resistivity of Nb-doped TiO 2 thin films deposited at a high rate by reactive DC magnetron sputtering [Articolo su rivista]
Casotti, D.; Orsini, V.; di Bona, A.; Gardonio, S.; Fanetti, M.; Valant, M.; Valeri, S.
abstract

We report on the long-term stability of electrical resistivity in Nb-doped TiO 2 thin films grown at a high rate by a reactive DC magnetron sputtering from metallic targets. The high deposition rate is obtained by an active control of the oxygen flow during the growth process. Film microstructure and preferential orientation of the crystallites are controlled by the total working pressure in the film growth process. After a heat treatment in vacuum, the film resistivity is in a 10 −3 Ω cm range and the optical transmission higher than 80% in the visible region. While the film is stable when kept under dry nitrogen, significant ageing has been observed when the material is exposed to air. In this case, the DC resistivity steadily increases and fractures form throughout the film. The ageing process is discussed in terms of the evolution of the film microstructure and/or the oxygen exchange through on the film surface. Oxygen uptake from ambient air is confined to a shallow surface region. It is possible that this mechanism triggers the formation/propagation of the fractures that predominantly contribute to the increase in film resistivity.