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Alessandro GUALTIERI

Department of Chemical and Geological Sciences

Content class: Applied crystallography

Class: GEOLOGICAL SCIENCES AND TECHNOLOGIES (D.M.270/04) (Offer 2017)
  • CFU: 6
  • SSD: GEO/06

Objectives

Modulo 1 – responsabile G. Vezzalini To be able to choose and apply the diffraction methodology more appropriate for the structural determination or refinement of a natural or synthetic material. To be able to apply this methodology to the characterization and definition of material properties. Modulo 2 – responsabile A.F. Gualtieri The main goal of this course is to take the student to a good level of knowledge, both theoretical and practical, to the techniques of mineralogical analysis and use of the Rietveld method for the structure and quantitative phase analysis with a special attention to mineral assemblages and raw materials. Following the theoretical lessons and attending the lab training, the student should be capable of: (i) applying the Rietveld method to powder systems of interest in material science; (ii) using the GSAS package and the graphical interface EXPGUI; (iii) performing a structure refinement of low-average complexity; (iiii) performing a refinement for the quantitative phase analysis of simple and highly complex systems containing an amorphous phase.

Prerequisites

Basic knowledge of structural crystallography, X-ray diffraction is required.

Course Syllabus

Modulo 1 – responsabile G. Vezzalini Review/reminder of structural crystallography and X-ray diffraction theory. Interpretation and use of International Crystallographic Tables. Structure factor. Reciprocal lattice, Ewald diffraction sphere, limit sphere. Systematic extinctions. Anomalous diffusion. Atom thermal vibration. Electronic density. Fourier transform. Structural resolution methods: Patterson, direct methods, charge flipping, heavy atom. Structure refinement. Description of instruments for single crystal X-ray diffraction. Modulo 2 – responsabile A.F. Gualtieri The use of X-ray powder diffraction techniques for the mineralogical qualitative analysis, quantitative analysis, structure refinement, and microstructure analysis. Conventional and non-conventional sources, geometries and detectors for X-Ray powder diffraction with a special attention to the parafocusing Bragg-Brentano geometry. a powder pattern. Theory and applications of quantitative phase analysis. The use of crystallographic databases. The Rietveld method applied to the quantitative phase analysis and structure refinement. The combined RIR-Rietveld method for the determination of the amorphous fraction. The GSAS package and the graphical interface EXPGUI. Other dedicated software. Exercises on the structure and quantitative analysis: the structure of corundum, quartz, olivine, goethite, zeolites, ternary and complex mixtures.

Reference texts

-Dispense preparate dai docenti disponibili in formato elettronico (files PPT). -Fundamentals of Crystallography. C.Giacovazzo Ed. IUCr Text on Crystallography. 7.Oxford Science Publications. -R.E. Newnham – Properties of Materials – Oxford University Press -A. Putnis – Introduction to Mineral Sciences - Cambridge University Press -H.R Wenk, A. Bulakh – Minerals, their constitution and origin – Cambridge University Press -R.A. Young – The Rietveld method. Oxford Science Publication.

Teaching methods

Lectures in "ex cathedra" mode integrated with practical class activities. Attendance to the course is mandatory.

Verification of learning

Modulo 1 Final, oral examination with mark in thirtieths on specific subjects treated during the course. Modulo 2 Final individual examination with mark in thirtieths to be averaged with the score from the exam of Modulo 1, delivered as practical test (ex. Rietveld refinement).

Expected results

The student has to be able: to choose the most appropriate X-ray diffraction methodology to characterize a mineral or a crystalline industrial material;to use X-ray diffraction data on single crystal for the structural resolution and refinement;to understand the theoretical and practical bases of the X-ray powder diffraction methods for the mineralogical analysis, and the Rietveld method. The student has to use the X-ray diffraction to solve or refine the crystal structure of minerals and to apply the results to the comprehension of rock crystal-chemistry, genesis and structural deformations induced by geological processes. In the case of synthetic materials the student has to be able to correlate structure and properties for industrial applications. The student will be able to deepen and develop topics relative to the relationships structure-properties and discriminate the mass media news; identify objectives, roles and public responsibilities in the raw materials and synthetic phases management. The student has to be able to popularize the importance of the study of the structural characteristics of natural and synthetic phases for their applications in geology and in economic fields; present in a rational, brief and through way objectives, concepts and results of crystallography and its applications; disseminate technical data in English; use information technologies to elaborate the experimental data. The student will be able to deepen independently the known topics and to apply the scientific method to formulate and verify theories.