ELECTRON SPECTROSCOPIC DIFFRACTION

Electron spectroscopic diffraction (ESD) in an energy-filtering electron microscope (EFEM) offers the possibility to record electron diffraction patterns with different energy-selecting windows. Zero-loss filtering of elastically scattered electrons removes the contribution of inelastically scattered electrons and increases the contrast of amorphous, small-angle and Debye-Scherrer diffraction patterns. The diffraction patterns recorded by energy losses can be described by a convolution with the angular distribution of inelastically scattered electrons. Diffraction patterns of single-crystal foils at selected energy losses contain information about the inelastic scattering processes. Zero-loss filtering separates the Bragg spots, the Kikuchi lines and bands and the thermal diffuse streaks generated by electron-phonon scattering. The system of Kikuchi lines and bands changes with increasing energy loss and broadening of the angular distribution. At energy losses of a few hundred eV the diffraction pattern of a single-crystal foil consists of excess of defect Kikuchi bands, also depending on foil thickness and ionisation edges. We report in this paper some applications and results of electron diffraction experiments with 80 keV electrons in a commercial EFEM (Zeiss EM 902). © 1990.