Interaction and He sup + and Ne sup + ions with Ni(100)K and Cu(100)K surfaces having variable potassium coverage.

This paper presents an electron spectroscopic study employing slow He sup + and Ne sup + ions incident on Ni(100) and Cu (100) surfaces with varying amounts of adsorbed potassium. Investigation of the changes in electron energy spectra as work function of the surface is varied probes the pattern of resonance tunneling, excitation conversion, and Auger ejection processes. When the surface is clean the work function empty set is high and the mode of electron ejection is the two-electron process of Auger neutralization of the incident ions yielding a folded two-electron spectrum.