Resonant soft X-ray emission study of rutile (TiO2)

The Ti2p and O1s soft X-ray emission spectra were measured on rutile (TiO2) in the energy region of Ti2p and O1s-excitation threshold. The ordinary fluorescence spectra resolve the valence band into the Ti3d and O2p components. On the other hand, a Raman and an elastic scattering peaks were observed in the soft X-ray emission spectra, The Raman scattering peak is resonantly enhanced at excitation energies corresponding to Ti2p absorption peaks. The Raman scattering is assumed to be caused by the elementary excitation of charge transfer excitation from O2p valence band to Ti3d conduction band. The O1s- and Ti2p-absorption spectra shift to lower energy by about 0.5 and 2.2 eV due to core hole potentials, respectively.