Influence of localized inelastic scattering on Kikuchi bands in photoelectron diffraction patterns

In the treatment of inelastic processes in photoelectron diffraction calculations, the decay of the elastically scattered waves in the crystal structure is considered in an average way by the introduction of the inelastic mean free path (IMFP). The IMFP is only a single parameter that does not depend on the position or direction within a crystal and thus neglects the specific influence of the crystalline structure on inelastic scattering processes. In order to go beyond the IMFP picture, the Kikuchi band approach to photoelectron diffraction treats the scattering potential and its absorptive part in Fourier space and allows to incorporate localized inelastic scattering into photoelectron diffraction simulations. It is demonstrated that inelastic scattering processes that are localized on atomic planes (i.e. phonon scattering) can lead to contrast reversal of Kikuchi bands if the measured group of electrons dominantly originates from a crystal region which is located sufficiently far away from the surface and anomalous absorption of Bloch waves thus becomes relevant.