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

Institut für Physik der Humboldt-Universität zu Berlin Invalidenstr. 110, D-10115 Berlin, Germany

Received: 26 November 1997
Accepted: 17 December 1997

Abstract

From studies on the energy loss of fast atomic projectiles () ranging from protons to potassium ions in the scattering from a clean and flat Al(111)-surface under a grazing angle of incidence, we derive stopping powers as a function of distance from the surface plane. We observe that oscillations for the stopping powers with atomic number Z₁ show a pronounced dependence on the electron density as predicted by nonlinear density-functional calculations. For sufficiently low electron densities, those oscillations follow the intuitive picture in showing minima of stopping for projectiles with noble-gas configurations.