Low-Energy-Electron Diffraction from Al(100), Al(110), Al(111), and Cu(100)

Abstract

The results of model calculations of the intensities of low-energy electrons, $20\ensuremath{\lesssim}E\ensuremath{\lesssim}200$ eV, scattered from Al(100), Al(110), Al(111), and Cu(111) and performed using a three-partial-wave inelastic-collision-model analysis, are presented. Comparison of a comparable matrix-inversion analysis with the second-order perturbation calculation of Tong and Rhodin indicates the accuracy of perturbation theory for strong potentials which cause predominantly forward scattering. Each member of a set of models which includes that of Tong and Rhodin describes well the scattered intensities from Al(100) near normal incidence. However, the models fail to describe adequately a more extensive set of data taken at larger angles of incidence and on the (110) and (111) faces. Comparisons between model calculations and absolute-intensity measurements for Cu(100) indicate that the model describes satisfactorily the nonspecular absolute intensities but not those of the specular beam for small values of the angle of incidence.