The influence of electron exchange and relativistic corrections on elastic low energy electron diffraction from compound semiconductors

Abstract

The model of the electron-solid interaction used for dynamical low energy electron diffraction (LEED) calculations is extended to include both an energy dependent local exchange interaction and relativistically computed ion-core charge densities. These extensions of earlier work based on non-relativistic, local exchange models are tested for the (110) surfaces of InP, ZnTe and InSb. Calculations reveal discernible differences between LEED intensities computed using the energy dependent exchange force and those obtained using energy independent local exchange forces. The replacement of the non-relativistic ion-core potential with a relativistic one produces smaller changes which are most apparent when the energy dependent exchange force is used for compound semiconductors containing one or more components from the fifth row or lower in the periodic table (e.g., Cd, In, Sb or Te).