Observation of electronic structure in conduction band of CaTiO₃

Electronic structure in the conduction band of CaTiO₃ was examined by the bremsstrahlung isochromat spectroscopy (BIS), X-ray absorption spectroscopy (XAS) and electron energy loss spectroscopy (EELS). Two broad bands were observed at 2 and 7 eV above the Fermi energy in the BIS spectrum. The features of the XAS spectra for Ca L_2,3, Ti L_2,3, and O K edges were almost the same as those of the EELS spectra, and the XAS spectrum for each element was in reasonable agreement with its partial density of states estimated by an energy band calculation. A trial spectrum was synthesized by the sum of the XAS spectra, and it was found that the feature of the synthesized spectrum is similar to that of the BIS spectrum. From the comparison between XAS and BIS spectra, the two broad bands at 2 and 7 eV in the BIS spectrum were assigned to Ti 3d bands and Ca 4s bands, respectively.