Dynamical simulations of energy-filtered inelastic electron diffraction patterns

Abstract

The previously proposed inelastic scattering theory [Wang (1991). Acta Cryst. A47, 686–698] has been applied to simulate the diffraction patterns of phonon, plasmon-loss and atomic core-shell scattered electrons. The details of the calculation method and the program flow chart are described here. The calculated thermal diffuse scattering (TDS) patterns using full lattice dynamics agree well with the experimental observations for parallel- and convergent-beam-illumination cases. The results have shown that the Kikuchi pattern is mainly produced by phonon-scattered electrons and that the Einstein model is not a good thermal-vibration model, at least for molybdenum and silicon. Under strongly diffracting conditions, calculations for energy-filtered diffraction patterns of core ionization edges have shown that the elastic and inelastic scattering can no longer be considered as independent and that the angular distribution of the inelastically scattered electrons cannot be simply described by the Lorentzian function. All these dynamical effects can affect the compositional microanalysis in electron energy-loss spectroscopy (EELS).