The charge distribution of the defect states at the reduced TiO2(110) surface was studied via a new method, the resonant photoelectron diffraction. The diffraction pattern from the defect state, excited at the Ti-2p-3d resonance, was analyzed in the forward scattering approach and on the basis of multiple scattering calculations. The defect charge was found to be shared by several surface and sub-surface Ti sites with the dominant contribution on a specific subsurface site in agreement with density functional theory calculations.

Defect States at the TiO2(110) Surface Probed by Resonant Photoelectron Diffraction. Krüger, P., Bourgeois, S., Domenichini, B., Magnan, H., Chandesris, D., Le Fèvre, P., Flank, A.M., Jupille, J., Floreano, L., Cossaro, A., Verdini, A., Morgante, A.: Physical Review Letters, 2008, 100[5], 055501