Tetragonal-cubic phase transition in BaTiO sub(3) probed by resonant X-ray emission spectroscopy

• Published in: Journal of electron spectroscopy and related phenomena Vol. 184; no. 3-6; pp. 207 - 209
• Main Authors: Isohama, Yoichi, Nakajima, Nobuo, Maruyama, Hiroshi, Tezuka, Yasuhisa, Iwazumi, Toshiaki
• Format: Journal Article
• Language: English; French; German
• Published: 01.04.2011
• Subjects: Absorption; Barium titanates; Curie temperature; Emission spectra; Phase shift; Phase transformations; X-rays
• ISSN: 0368-2048
• DOI: 10.1016/j.elspec.2010.12.023

Ti K beta resonant X-ray emission spectra (RXES) of barium titanate powder were measured at several temperatures to investigate the microscopic origin of the tetragonal-cubic phase transition. The fluorescence peaks that evolved from de-excitation processes between discrete energy levels are insensitive to temperature change. However, one of two Raman peaks caused by charge transfer (CT) excitation shows an energy shift across the Curie temperature (T sub(C)), accompanied by structural phase transition, which was confirmed by X-ray diffraction measurements. The shifted CT peak retained its intensity at T sub(C) because of a fluctuating local polarization. We propose that RXES measurement is a useful method to probe the local covalency in close proximity to an absorbing atom. Tetragonal-cubic phase transition of BaTiO sub(3) is studied by resonant X-ray emission. [inline image] One charge-transfer peak shows an energy shift across the Curie temperature. [inline image] The shifted peak remains its intensity even in a high temperature cubic phase. [inline image] Resonant X-ray emission spectra can probe the local covalency of an absorbing atom.