Electronic excitation spectra and energy losses of slow ions in solids

Abstract
We have calculated the energy distribution P(ɛ) of electrons excited by a slowly moving atomic particle in a metal. The particle is represented by an empirical pseudopotential which is known from electronic band structure calculations. The first moment of P(ɛ) yields the value of the total energy of excited electrons or, equivalently, the value of the energy losses of the moving particle. The electronic stopping power of Al atoms moving in aluminum calculated by this method is in quantitative agreement with the stopping power obtained by other approaches. The corrections to P(ɛ) due to the deviation of real metals from the free-electron model are also estimated. P(ɛ) can be used in theories of ion-induced kinetic electron and ion emissions as a source function for calculating the energy spectra of electrons excited in collision cascades.