Effects of Deviations from the Bethe Model on LEED Intensities for an Exactly Soluble One‐Dimensional Model

Abstract

The effects of deviations from elastic scattering from perfectly periodic potentials on LEED intensities is investigated for an exactly soluble one‐dimensional model. The model consists of a perfectly periodic semi‐infinite substrate with delta function scatterers and a selvage consisting of a finite number of arbitrarily spaced delta functions of arbitrary scattering strength. Inelastic processes are included by means of a complex potential. Calculations are performed for the perfect crystal, the crystal with surface scatterers of different strength than in the bulk, variable lattice spacing near the surface, both localized inelastic scattering at the lattice sites and bulk inelastic processes, and combinations of these conditions. The results, which include shifting of the center and decrease in intensity of the Bragg peaks, symmetric and asymmetric broadening of the peaks and peaks not associated with Bragg reflection from the bulk, are discussed in terms of the wavefield of the incident electron in the crystal.