Energy loss of ions moving near a solid surface.

Abstract

The energy loss of an ion moving parallel to a solid surface is studied within the dielectric function formalism. Based on the specular-reflection model, the surface response function can be expressed in terms of the bulk dielectric function, and the effect of the exchange-correlation interaction of electrons in the solid is taken into account by the local-field correction dielectric theory. For low-velocity ions, semianalytical expressions of the energy loss are obtained. In the high-velocity limit, the contributions of the surface plasmon to the energy loss are studied using the hydrodynamic approximation (HA) and the plasmon pole approximation (PLA) to the bulk dielectric function. It is found that at low velocity, the exchange-correlation interaction of electrons enhances the magnitude of the energy loss, but at high velocity, its effect is less important, and both the HA and the PLA provide an adequate description for surface-plasmon description. \textcopyright{} 1996 The American Physical Society.