The electronic structure of Cs adsorbed on Mo(111)

The main loss observed in an ELS study of Cs adsorbed on Mo(100) is described as an interband transition with initial and final states in the adsorbate. This interpretation is preferred to that involving the plasmon excitation mechanism observed for Cs on Cu(111) in the coverage range where the Cs has a metallic nature. The occurence of this transition is assumed to be related to the substrate effect.