Effects of Electronic Excitations on Translational Energy Distribution of Ions Scattered by Metal Surfaces

Abstract

Effects of electronic excitations are investigated on thetranslational energy distribution of ions scattered by metalsurfaces. Coupling between the translational motion of ion and degreesof freedom of metal electron system is taken into account explicitly, in the framework of model consisting of the non-interactingNewns-Anderson Hamiltonian for the electron system and translationalenergy of the ion. It is shown by perturbational calculation thatwithin the Born-Oppenheimer approximation (BOA), a logarithmicsingularity comes out in the energy distribution of ions scattered bymetal surfaces as a Fermi surface effect. Further, it is shown thatbeyond BOA this singularity is weakened by interplay betweenelectronic state transitions and state changes of ion motion duringscattering process.