Spin-polarized electron excitation during the neutralization of He + ions in metals

Abstract

Spin-resolved electron spectra collected during the neutralization of spin-polarized He + ions at metal surfaces and bulk contain wide information about the target electronic properties, as well as on the neutralization process itself. The interpretation of such electron spectra, however, requires a deep understanding of the interaction mechanisms between the polarized He + projectile and the metal electrons. Density functional theory (DFT) and the local spin density (LSD) approximation are used to study the piling-up of charge induced by a static He + ion in a metal, the latter described within the jellium model. Furthermore, the rate for the neutralization of very slow He + undergoing Auger processes inside the metal is calculated. The spin polarization of the electrons excited in the Auger neutralization process, as well as the role of spin in the screening and neutralization of the incident He + ions are also discussed.