OVERVIEW

The course is devoted to the diffraction techniques for the study of crystalline materials.

AIMS AND CONTENT

LEARNING OUTCOMES

At the end of the course students are expected to have acquired the knowledge on the theoretical principles of diffraction; to know the main experimental techniques and their possible use; to be able to understand and interpret the diffraction data, to solve simple crystallographic problems.

TEACHING METHODS

The course is done in a traditional way, with lectures and exercises. The lectures are interspersed with exercises and examples that are carried out with the contribution of all students.
Usually, the practical experiences are activities carried out by means of a computer; they take place in the classroom for groups of students

SYLLABUS/CONTENT

- Elements of elementary crystallography: symmetry elements, crystal lattices, point groups, space groups. Planes and crystallographic directions. Description and use of the International Tables of Crystallography.

- Diffraction theory : Nature and production of the RX. Safety and practical considerations. X-ray diffraction and neutron/electron diffraction (notes). Scattering factor and structure factor. Bragg's law, reciprocal lattice, Ewald sphere.

- Experimental techniques: Diffraction from polycrystalline samples and single crystals. Sample preparation. data acquisition strategies. Use of crystallographic databases.

Resolution and structural refinement: The intensity of the diffraction peaks. The electron density. The phase problem. Solution methods: synthesis of Patterson, direct methods.

Practical exercises: Identification of the phases present in a polycrystalline sample; structural refinement with the Rietveld method; structural resolution "ab initio" using of intensity 'data from single crystal and / or powders.

RECOMMENDED READING/BIBLIOGRAPHY

Besides the material available on Aulaweb, the following textbooks are recommanded:

A. Immirzi, C. Tedesco, “La diffrazione dei cristalli” 2a Edizione. Cooperativa Universitaria Athena

C. Giacovazzo, H.L. Monaco, G. Artioli, D. Viterbo, G. Ferraris, G. Gilli, G. Zanotti, M. Catti “Fundamentals of Crystallography” Ed. C. Giacovazzo

M.F.C. Ladd, “Symmetry in molecules and crystals”

G.H.Stout, L.H.Jensen, “X-ray structure determination”, Macmillan Publishing Co, N.Y (1968)

V. K. Pecharsky, P. Y. Zavalij, “Fundamentals of powder diffraction and structural characterization of materials”

Kluwer Academic Press

Tabelle Internazionali di Cristallografia Vol.1-4

TEACHERS AND EXAM BOARD

Exam Board

MARCELLA PANI (President)

CRISTINA ARTINI

MARIA CARNASCIALI

PIETRO MANFRINETTI

LESSONS

LESSONS START

The class starts with the beginning of the second semester

Class schedule

The timetable for this course is available here: Portale EasyAcademy

EXAMS

EXAM DESCRIPTION

Students can choose two different methods of examination: 1) traditional oral exam on various topics covered during the course. Usually three questions, one of which is on the theoretical part, one on experimental techniques, one on aspects concerning the interpretation and analysis of structural data. 2) An in-depth essay on a topic of crystallography, previously agreed. For the latter method both a written report and an oral presentation are required. The oral examination is always conducted by two faculty members and on average has a duration of at least 40 minutes; the commission will thus be able to verify wether the educational objectives are reached or not . When these are not met, the student is invited to deepen the study and to use further explanations by the teacher

ASSESSMENT METHODS

Both the reasoning capacity of the student and his skill in solving simple theoretical problems are evaluated. The examination should ascertain whether the student has acquired the theoretical concepts of diffraction, and if it is able to apply them to simple real examples

Exam schedule