ULTRATHIN NICKEL-OXIDE ON THE V2O3/CU(100) SURFACE STUDIED BY XPS

The interaction of nickel ions with thin vanadium oxide on Cu(100) was studied by X-ray photoelectron spectroscopy. After O-2 oxidation of submonolayer nickel atoms on the vanadium oxide, a single Ni2p(3/2) peak was observed at 855.9 eV;the oxide was quite different in binding energy and spectral features from the surface oxide grown on single-crystal nickel substrates. This indicates that the electronic states of the nickel ions are considerably changed by interaction with the oxygen anions of the vanadium oxide. The interaction is associated with a shift of the V2p(3/2) peak to higher binding energy. During growth of the nickel oxide by repeated deposition (0.5 monolayer of Ni) and oxidation, the initial nickel ions are changed into the NiO structure, followed by a weakening of the interaction with the vanadium oxide. The interaction diminishes with adsorption of acetate on the surface.