Electron binding energies of core levels in caesium adsorbed on a nickel (100) surface

Abstract

Electron binding energies obtained from X-ray photoemission and workfunctions obtained from UV photoemission have been recorded for caesium adsorbed on nickel (100) at coverages from 0.1 to >1.0 monolayer. Analysis of coverage as a function of Cs+ dose suggests a sticking coefficient of 0.5 for Cs+ on nickel (100) in submonolayer range and 0.05 above a monolayer of deposited caesium. The binding energy of the caesium 3d5/2 level, referred to the Fermi energy of the adsorption system, is 726.0+or-0.2 eV, independent of coverage. Comparison of binding energies of atomic caesium and caesium adsorbed at saturation coverage shows that the total change in electron binding energy, Delta EB, depends on the core levels studied (5s to 3s); subtracting a modified relaxation energy yields a solid state shift in binding energy of 2-4 eV.