**Are you an EPFL student looking for a semester project?**

Work with us on data science and visualisation projects, and deploy your project as an app on top of GraphSearch.

Lecture# Electron Diffraction: Basics & Applications

Description

This lecture covers the fundamentals of electron diffraction, including topics such as diffraction theory, crystallography, symmetry, and the reciprocal lattice. It explores the use of electron diffraction in studying crystal structures, symmetry relationships, and twinning phenomena. The presentation also delves into advanced techniques like convergent beam electron diffraction and the interpretation of diffraction patterns. Practical applications of electron diffraction in materials science and nanotechnology are discussed, highlighting its importance in characterizing crystal structures and interfaces.

Official source

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

In course

Instructors (2)

MSE-352: Introduction to microscopy + Laboratory work

Ce cours d'introduction à la microscopie a pour but de donner un apperçu des différentes techniques d'analyse de la microstructure et de la composition des matériaux, en particulier celles liées aux m

Related concepts (193)

Related lectures (134)

Diffraction

Diffraction is the interference or bending of waves around the corners of an obstacle or through an aperture into the region of geometrical shadow of the obstacle/aperture. The diffracting object or aperture effectively becomes a secondary source of the propagating wave. Italian scientist Francesco Maria Grimaldi coined the word diffraction and was the first to record accurate observations of the phenomenon in 1660.

Electron diffraction

Electron diffraction refers to changes in the direction of electron beams due to interactions with atoms. Close to the atoms the changes are described as Fresnel diffraction; far away they are called Fraunhofer diffraction. The resulting map of the directions of the electrons far from the sample (Fraunhofer diffraction) is called a diffraction pattern, see for instance Figure 1. These patterns are similar to x-ray and neutron diffraction patterns, and are used to study the atomic structure of gases, liquids, surfaces and bulk solids.

Fraunhofer diffraction

In optics, the Fraunhofer diffraction equation is used to model the diffraction of waves when plane waves are incident on a diffracting object, and the diffraction pattern is viewed at a sufficiently long distance (a distance satisfying Fraunhofer condition) from the object (in the far-field region), and also when it is viewed at the focal plane of an imaging lens. In contrast, the diffraction pattern created near the diffracting object and (in the near field region) is given by the Fresnel diffraction equation.

X-ray crystallography

X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angles and intensities of these diffracted beams, a crystallographer can produce a three-dimensional picture of the density of electrons within the crystal. From this electron density, the mean positions of the atoms in the crystal can be determined, as well as their chemical bonds, their crystallographic disorder, and various other information.

Crystal structure

In crystallography, crystal structure is a description of the ordered arrangement of atoms, ions, or molecules in a crystalline material. Ordered structures occur from the intrinsic nature of the constituent particles to form symmetric patterns that repeat along the principal directions of three-dimensional space in matter. The smallest group of particles in the material that constitutes this repeating pattern is the unit cell of the structure.

Deviation from Bragg scattering

Covers electron diffraction theory, Bragg's law, reciprocal lattice, Ewald sphere, and weak-beam dark-field imaging.

Electron Diffraction: Basics & ApplicationsMSE-352: Introduction to microscopy + Laboratory work

Explores electron diffraction basics, including Bragg's law, reciprocal lattice, and applications like crystal phase discrimination.

Electron Diffraction: Basics & ApplicationsMSE-352: Introduction to microscopy + Laboratory work

Covers the basics of electron diffraction, explaining contrast in TEM images and its applications in material analysis.

Reciprocal Lattice and Diffraction

Explores reciprocal lattice in 2D systems, diffraction from lattice and atomic structures, emphasizing scattering and constructive interference.

Electron Diffraction: Basics and Applications

Covers the fundamentals of electron diffraction and its applications in understanding crystal structures and symmetry, including lattice vectors, lattice planes, and dark-field imaging techniques.