RESONANT PHOTOELECTRON-SPECTROSCOPY STUDIES OF BATIO3 AND RELATED MIXED OXIDES

Synchrotron radiation-based ultraviolet photoelectron spectroscopy (UP S was used to investigate the electronic structure of BaTiO3 and relat ed mixed oxides. In particular, resonant photoelectron effects at the Ti 3p threshold provide a picture of the contribution of the Ti 3d sta tes to the predominantly O 2p valence band, and thus produce informati on on Ti 3d-O 2p hybridization. This is used to determine the Ti-O hyb ridization in BaTiO3 and comparisons are made to the Ti partial densit y of states obtained from first principles calculations of the band st ructure of BaTiO3. We have also investigated the effects of substituti on of Nd for Sr in SrTiO3 to form the mixed oxide Nd1-xSrxTiO3. These studies illuminate the effects of changing crystal structure and bandf illing on Ti 3d-O 2p hybridization.