Photoemission from Ne, Ar, Kr and Xe layers on Ni(110) and Ga films

Abstract

UP spectra were measured for rare gas monolayers of Ne, Ar, Kr and Xe using HeI (21.2 eV) light. For Ar and Kr the binding energy of the valence p electrons does not depend on the metal if it is referred to the vacuum level of the bare metal surface. For Xe the remaining binding energy differences demonstrate an influence of the metal on the initial state. A Ne layer was prepared for the first time on a clean nickel single crystal surface. It behaved in similar fashion to Ar and Kr. For second layers of the other three gases the binding energy was shifted by 0.8 eV to higher values upon both metals. It is argued that this change can be due to a change of the vacuum level to which the different layers are attached instead of a difference in shielding of the final state.