High-spin configuration of Co(III) in nonstoichiometric Co3O4 films. XPS investigations

Nonstoichiometric Co3O4 films have been investigated by the XPS technique. Analysis of binding energies and intensities of the Co 3s, Co 2p and O 1s core-level peaks and valence band spectra has led to a conclusion that, in contrast to bulk samples, the high-spin configuration of Co(III) ions in nonstoichiometric Co3O4 films is stabilized in the spinel octahedral sublattice. The relation between the electronic structure and the catalytic activity of nonstoichiometric cobalt oxide is discussed.