Theoretical Study on the High-Energy Electron Energy Loss Spectroscopy Compared with X-Ray Absorption Spectroscopy. II. Effects of Single Elastic Scattering

Abstract

In this paper we propose a new theoretical approach to high-energy electron energy loss spectroscopy (EELS) based on the short-range order theory which includes elastic scattering before and after deep core excitation. Within the single elastic scattering approximation for the fast electron, numerical calculations have been performed on the K-edge EELS from diamond (111) and Al (111), (001) surfaces for three different modes: the grazing incidence and low takeoff angle detection mode, the backward scattering reflection mode and the transmission mode. The calculated results show that the dipole excitation mainly contributes at small-angle scattering as expected, and the elastic scatterings recover the dipole excitation contribution substantially at large-angle scattering; however, the nondipole processes are dominant even under the large-angle scattering condition.