Surface Molecular Structure from Ion-Neutralization Spectroscopy of Electrons in Surface Orbitals

Abstract

It is shown that the ion-neutralization spectroscopy determines the orbital energy spectra of surface molecules formed of adsorbed foreign atoms and surface atoms of the substrate. For free molecules such a spectrum yields information concerning molecular symmetry and structure as well as ionicity within the molecule. Using also measured work-function change in adsorption, specific conclusions are drawn concerning O, S, and Se adsorbed in $p(2\mathrm{}\times 2)$ and $c(2\mathrm{}\times 2)$ arrangements on Ni (100).