Analysis of Low-Energy Electron Diffraction from the (100), (110), and (111) Faces of Aluminum

Abstract

Experimental low-energy-electron-diffraction (LEED) intensity profiles from the (100), (110), and (111) faces of clean aluminum are analyzed using a version of the inelastic-collision model which incorporates the effects both of lattice vibrations and of a "realistic" model of the electron-ion-core potential as described by its $l\ensuremath{\le}2$ partial-wave phase shifts. The data consists of specular and nonspecular beams in the energy range 0-180 eV for angles of incidence between 0\ifmmode^\circ\else\textdegree\fi{} and 25\ifmmode^\circ\else\textdegree\fi{}. Treating the surfaces as if they were simply truncations of the bulk solid provides an adequate qualitative description of the data from Al (100) and Al (111). Analysis of the data from Al (110) suggests a contraction of the upper-layer spacing by about 10%. The failure of the calculations to describe the fine structure in the observed intensities for large angles of incidence is attributed to uncertainties in our model of the electron-solid force law.