VALENCE BAND DENSITIES-OF-STATES OF TIO2(110) FROM RESONANT PHOTOEMISSION AND PHOTOELECTRON DIFFRACTION

We have performed a resonant photoemission (ResPE) and a photoelectron diffraction (XPD) study on a stoichiometric TiO2(110) crystal and have deduced Ti3d and O2p valence-band partial densities-of-states (VBPDOS) projected along the surface normal from these data. It is for the first time that both of these physically very different methods are applied to a crystal in order to extract the same set of information. Both experimental VBPDOS's show that the hybridization between O2p and Ti3d orbitals extend over the whole mainly O2p derived valence band. A comparitive discussion of the densities obtained from the two different methods and from electronic-structure calculations for bulk TiO2 and (110) surfaces is given.