Electron Microscopy, Crystallography

The structural characterization of materials is a mandatory prerequisite for developing functional materials and an absolute must for materials science researchers and engineers. For the interpretation of diffraction patterns, structures, microstructures, etc., detailed knowledge of crystallography, structure analysis, and the instruments used is necessary. The necessary knowledge is developed from scratch, progressively yielding an understanding of how to characterize materials by standard and sophisticated diffraction methods. The lecture also includes lab work on powder and single crystal diffractometers, allowing students to acquire the skills to correctly use and interpret diffraction data. The lecture during the^first semester essentially covers X-ray diffraction and electron microscopy, while the crystallography part continues during the^second semester with symmetry, structure solution, and structure refinements, as well as neutron scattering and magnetic structure analysis.

This lecture consists of two parts:

(1): Crystallography:

This part is essentially dedicated to familiarizing students with structure analysis and its application. After a brief introduction to the reciprocal lattice concept and the use of space groups in crystallography, the lecture focuses on structure analysis by diffraction methods using powder and single crystal X-ray and neutron scattering methods. This involves understanding related techniques, i.e. the use of powder and single crystal diffractometers, as well as the techniques and programs used today for structure refinements. The concept of the lecture is to introduce a basic understanding of what is behind the programs, rather than to use them blindly. Students will also collect single crystal diffraction data on a high-performance 4-cycle diffractometer with a 2D area detector, as well as magnetic structure analysis using neutron diffraction methods.

Simple inorganic structures: Space groups, X-ray/neutron and synchrotron sources, interaction of X-rays, electrons and neutrons with matter, reciprocal lattice, concept of Ewald sphere, powder diffractometers, single crystal diffractometers, orienting matrix, Patterson method, structure refinement from powder or single crystal data, magnetic structure analysis, magnetic space groups,

(2): Electron microscopy:

In this part, we will be interested in electron microscopy through flipped classes. We will discuss the following topics: Electron sources, lenses and aberrations, sample preparation, electron diffraction, structural and chemical analysis, imaging techniques.

Hourly volumes:

CM: 33 hours

Tutorial: 6 p.m.

Introduction to the structural characterization of condensed matter by diffraction methods at different correlation lengths.

The objectives of the transmission electron microscopy part are to provide solid knowledge in electron microscopy in order to be able to use appropriate methods for the characterization of materials. The expected skills for this part are detailed knowledge of the principles of an electron microscope (scanning and transmitted beam) and the ability to describe and schematize the device and its specificities.

Students will become familiar with diffraction methods and structure refinement methods from powder and single crystal diffraction data, which are analyzed by hand as well as using state-of-the-art programs.

The use of the flipped classroom promotes student engagement and investment. This way of working is interesting for acquiring knowledge and passing it on to the class.

Full CC

Crystallography:

- Brief review of symmetry and space groups

- Introduction to structure refinement (single crystal and powder methods)

- Magnetic structures with neutron diffraction

- Structure determination from single crystals (experiment and theory)

- Structure determination from powder diffraction data (experiment and theory)

- The applications of Fourier series for structure solution and refinements: from the Patterson Method to difference Fourier analysis

- Phase transitions, crystal twinning, and related changes in the direct and reciprocal lattices

- Contrast variation and anomalous scattering together with absolute structure determination

- Electron microscopy:

- In this part, we will be interested in electron microscopy through flipped classes. We will discuss the following topics: Electron diffraction, diffraction pattern, Electron sources, lens and aberrations, sample preparation, electron diffraction, Structural and chemical analysis, Imaging techniques.

Administrative contact(s):

Master's Program in Chemistry Secretariat Master's degree in Chemistry @ umontpellier.fr

• Transmission Electron Microscopy, A Textbook for Materials Science, Davis B. Williams, C. Barry Carter
• Physical Principles of Electron Microscopy, Ray F. Egerton, Springer
• and C. McKie: Essentials of Crystallography, Blackwell Scientific Publications
• Borchardt-Ott: Crystallography: an introduction, Springer
• Als-Nielsen, D. McMorrow: Elements of Modern X-ray Physics
• Massa: Crystal Structure Determination, Springer
• Stout-Jensen: X-ray Structure Determination, Academic Press
• L. Squires: Introduction to the theory of thermal neutron scattering, Oxford, Cambridge University Press
• Neutron and Synchrotron Radiation for Condensed Matter Studies Part I and II, Springer, Editors: Baruchel, J., Hodeau, J.-L., Lehmann, M.S., Regnard, J.-R., Schlenker, C. (Eds.)