Stopping of slow ions in the electron selvedge of a metal surface

Abstract

From studies on the energy loss of fast atomic projectiles (v = 0.5 v0) rangingfrom protons to potassium ions in the scattering from a clean and flatAl(111)-surface under a grazing angle of incidence, we derive stopping powers asa function of distance from the surface plane. We observe that oscillations for thestopping powers with atomic number Z1 show a pronounced dependence on theelectron density as predicted by nonlinear density-functional calculations. Forsufficiently low electron densities, those oscillations follow the intuitive picturein showing minima of stopping for projectiles with noble-gas configurations.