Ultraviolet inverse photoemission study of the oxidation of YFe2

The evolution of the empty valence-electron states of a polycrystalline YFe2 sample upon oxidation at room temperature is studied with inverse photoemission spectroscopy in the photon energy range 10–20 eV. The analysis of the oxidized spectra shows a progressive localization of the d-states upon oxidation and allows the roles of Y and Fe in the oxidation process to be addressed. These results are in agreement with the behaviour observed for the empty electron states of Zr2Fe upon oxidation, suggesting a common picture for describing the surface oxidation of alloys involving low d-occupancy and high d-occupancy metals.