Photoemission and Bremsstrahlung Isochromat Spectroscopy Studies of TiO₂(Rutile) and SrTiO₃

Photoemission and bremsstrahlung isochromat spectra have been measured on TiO 2 (rutile) and SrTiO 3 . The magnitudes of the fundamental band gaps estimated from the combined spectra agree well with the results of the photoabsorption and the energy-band calculations. The profiles of the observed spectra do not reveal the fine structure expected to occur in the density-of-states curves obtained by the energy band calculations, suggesting the existence of a mechanism to smear out the fine structure considerably. The combined spectra are used to interpret the charge-transfer-type satellite manifest in the core-level spectra. For 3 s photoemission, satellite features ascribed to the configuration interaction between the 3 s 3 p 6 and 3 s 2 3 p 4 3 d states in the atomic notation are also observed.