Electron Diffraction in the Transmission Electron Microscope

Abstract

Ch 1. DIFFRACTION AND THE ELECTRON MICROSCOPE. How a lens forms a diffraction pattern. Introduction to diffraction in the TEM. Selected-area diffraction pattern in the TEM. Low- (or small-) angle diffraction. Limitations to the accuracy of selected-area diffraction. Diffraction using small probes. Spatial resolution. Problems with specimens. Obtaining and recording a selected-area diffraction pattern in the TEM. Obtaining a CBED pattern. Alignments that are important for diffraction. Ch 2. THE RECIPROCAL LATTICE AND BRAGG'S LAW. Electrons as waves. Interference of waves. Bragg's law. The reciprocal lattice. Diffraction patterns from polycrystalline materials. Diffraction patterns from amorphous materials. Systematic absences. Standard patterns. Computer indexing of electron diffraction patterns.' Calibration of the camera constant. Calibration of the rotation between the image and the diffraction pattern. Using electron diffraction to identify unknown phases. Exercises. Ch 3. THE REFLECTING SPHERE. The reflecting sphere. Obtaining orientation relationships. Determining habit and composition planes. Exercises. Ch 4. FINDING YOUR WAY AROUND RECIPROCAL SPACE: KIKUCHI DIFFRACTION. How Kikuchi lines form. The determination of the deviation parameters. Kikuchi maps and their uses. Finding the exact orientation of the crystal. Exercises. Ch 5. THE INTENSITIES OF REFLECTIONS. The atomic scattering amplitude, f. The structure factor, Fhkl. The kinematic and dynamical theories of electron diffraction. Exercises. Ch 6. DETERMINATION OF THE BRAVAIS LATTICE, POINT GROUP AND SPACE GROUP. Determination of the crystal system from conventional electron diffraction patterns. Convergent-beam methods. Exercises. Ch 7. THE FINE STRUCTURE IN ELECTRON DIFFRACTION PATTERNS. Double diffraction. Diffraction from small particles. Diffraction from ordered structures. Periodic and modulated structures. Planar and linear defects. Thermal diffuse scattering. Exercises.