A low coverage study of NO on Ni(111) by angle resolved Auger electron spectroscopy at resonance excitation

Abstract

The local electronic structure of NO adsorbed on Ni(111) at 120 K has been studied down to low coverages by angle resolved Auger electron spectroscopy after resonant excitation to the bound π-resonance. The local electronic structure is independent of coverage in the range 0.05 ⩽ θNO ⩽ 0.5 ML; the orientation of the NO molecules is always perpendicular to the surface. The small value for Ueff = 0-2 eV for the various Auger final states indicates weak Coulomb interaction due to screening by the metal. Comparison of the Auger spectra after resonant excitation and excitation in the sudden limit shows that the initial state for the Auger decay is always the same well-screened state, independent of the primary excitation.