Thermal Diffuse Scattering of Low-Energy Electrons

Abstract

The thermal diffuse scattering of low-energy electrons is calculated in the high-temperature limit using the kinematical approximation. It is assumed that the electrons are scattered by the surface layer and that the thermal motions of the target can be approximated by the vibrations of an isotropic elastic continuum. It is found that the intensity of the scattered beam is inversely proportional to the perpendicular distance from the tip of the scattering vector to the nearest reciprocal lattice rod. It is shown that the effect of the free-surface boundary conditions is to double (approximately) the intensity without significantly changing the diffraction pattern. In the vicinity of the (00) rod, nearly half the intensity comes from the Rayleigh surface mode. Brief comparisons are made with experiment and with other theoretical treatments.