Study on electronic structure of CaTiO3 by spectroscopic measurements and energy band calculations

The electronic structure of CaTiO3 was experimentally examined by x-ray and ultraviolet photoemission spectroscopy, bremsstrahlung isochromat spectroscopy (BIS) and x-ray absorption spectroscopy. The photoemission spectra and BIS spectra were compared with the partial density of states (PDOS) estimated by an energy band calculation for a fundamental interpretation of the experimental spectra. The calculated PDOS were in reasonable agreement with the experimental energy spectra and the features in the spectra were interpreted by a comparison of the spectra with the PDOS. It was concluded that the top of the valence band mainly consists of O 2p orbitals in non-bending states and the bottom of the conduction band is composed of Ti 3d orbitals in d-p pi* anti-bonding states.