The interaction of gold with CeO2(111) layers was investigated with XPS, UPS and RPES (Resonant PhotoElectron Spectroscopy). Gold was deposited in steps onto a 1.5 nm thick CeO2(111) layer, epitaxially grown on a Cu(111) substrate.
The RPES showed a partial Ce4 Ce3 reduction, observed as a resonant enhancement of the 4f level of the Ce3 species. This can be explained by possible creation of a new Au ionic state.
The observed effects are stronger for Au deposition at room temperature than 250 °C. The results can be interpreted as a formation of a CeAuxO2 compound produced by gold - cerium oxide interaction.
The formed compound is probably located at the gold - cerium oxide interface.