Interaction potential for one-phonon inelastic He–Cu(111) and He–Ag(111) scattering

Abstract

The interaction potential for the elastic and inelastic scattering of low-energy He atoms from the Cu(111) and the Ag (111) crystal surface is derived from the sum of semi ab initio pair potentials modified by a damping function which takes into account the smoothing effect of the conduction electrons at large parallel momentum transfer. By adjusting only two free parameters of the potential model a very good fit to published experimental diffraction intensities and bound state levels is obtained. Without any further adjustment of the potential new experimental data of one-phonon inelastic reflection coefficients can be reproduced within the experimental error by calculations based on the distorted wave Born approximation. This new potential model has made it possible to study the dependence of the inelastic intensities on potential parameters and different experimental conditions.