Low-energy electron thermal diffuse scattering from Al(111) individually resolved in energy and momentum

Abstract

A low-energy-electron-diffraction (LEED) system which provides high resolution in energy and momentum simultaneously has been used to measure the intensity and the angular distribution of the thermal diffuse scattering (TDS) of Al(111) within the first surface Brillouin zone. The kinematic scattering theory is shown to provide a good description of the experimental results. Especially the one-phonon scattering is seen to decrease radially with distance |${\mathbf{K}}_{\mathrm{\ensuremath{\Vert}}}$| from the (00)-Bragg rod at about 1/|${\mathbf{K}}_{\mathrm{\ensuremath{\Vert}}}$|. Here the pioneering experiments of about 30 years ago are expanded and one-phonon, multiple-phonon, and elastic scattering throughout the Brillouin zone are separated in the experimental data with the help of energy resolution. The discussion shows to what extent TDS is affecting the defect analysis using a spot profile analysis of LEED without an energy resolution.