3p -> 3d resonant photoemission spectroscopy of a TiO2 sub-monolayer grown on Al2O3

The valence band resonant photoemission spectra of a TiO2 sub-monolayer grown on an Al2O3 substrate have been measured throughout the Ti 3p absorption edge, i.e. at photon energies between 40 and 60 eV. The resonance process has been analysed in terms of constant initial state (CIS) curves, showing a peak at 49.5 eV photon energy, corresponding to a Fano-like resonant process. The Ti 3d contribution to the valence band shows a significant energy shift with respect to bulk TiO2. These results are compared to cluster model calculations for a TiO6 cluster. (C) 2004 Elsevier B.V. All rights reserved.