ANGULAR-DEPENDENCE OF THE TI-K EDGE IN RUTILE TIO2

The angular dependence is investigated of the X-ray absorption spectrum of Ti K edge in TiO2 recorded in the total electron yield mode. Despite the weak distortion of the octahedral coordination, the absorption spectra exhibit wide contrast which enables designation of the excited state orbitals involved in the strong transitions. The energy splittings between the degenerate transitions in perfect octahedral symmetry are much more pronounced than could be expected from a one-electron ground state analysis. It is deduced that the first allowed transitions (i.e. Is --> 4p) seem to show sensitive dependence on the local symmetry. However, for the weak transitions before the edge, the analysis is not straightforward and is still in progress.