Electronic structure of BaTiO using resonant X-ray emission spectroscopy at the Ba-L and Ti K absorption edges

Yoshii, Kenji  ; Yoneda, Yasuhiro   ; Jarrige, I.*; Fukuda, Tatsuo  ; Nishihata, Yasuo; Suzuki, Chikashi ; Ito, Yoshiaki*; Terashima, Takahito*; Yoshikado, Shinzo*; Fukushima, Sei*

We have studied the electronic properties of ferroelectric BaTiO using two complementary bulk-sensitive spectroscopic probes, resonant X-ray emission spectroscopy (RXES) and X-ray absorption spectroscopy in the partial fluorescence mode (PFY-XAS). Contrary to a previous study, we found no temperature change of a PFY-XAS spectrum at the Ba L edge between room temperature and 150C. This result is not supportive of the possible presence of the displacement around Ba at the Curie temperature. RXES spectra were measured at the Ti K edge for BaTiO, along with SrTiO and La-doped metallic SrTiO. The photon energy of the emission peak is found to be nearly constant throughout the absorption edge for all three compounds. We deduce the Ti 3d states to have a delocalized character, in contrast with the Ba 5d states, a property which is consistent with the proposed scenario of the formation of electric dipoles in BaTiO.