標題: Pressure-induced structural distortion of TbMnO3: A combined x-ray diffraction and x-ray absorption spectroscopy study
作者: Chen, J. M.
Chou, T. L.
Lee, J. M.
Chen, S. A.
Chan, T. S.
Chen, T. H.
Lu, K. T.
Chuang, W. T.
Sheu, H. -S.
Chen, S. W.
Lin, C. M.
Hiraoka, N.
Ishii, H.
Tsuei, K. D.
Yang, T. J.
電子物理學系
Department of Electrophysics
關鍵字: electronic structure;high-pressure effects;Jahn-Teller effect;multiferroics;solid-state phase transformations;terbium compounds;X-ray absorption spectra;X-ray diffraction
公開日期: 1-Apr-2009
摘要: The variation of electronic states and structural distortion in highly compressed multiferroic TbMnO3 was probed by x-ray diffraction (XRD) and x-ray absorption spectroscopy (XAS) using synchrotron radiation. Refined XRD data enabled observation of a reduced local Jahn-Teller (JT) distortion of Mn sites within MnO6 octahedra in TbMnO3 with increasing hydrostatic pressure. A progressively increasing intensity of the white line in Mn K-edge x-ray absorption spectra of TbMnO3 was detected with increasing pressure. The absorption threshold of Mn K-edge spectra of TbMnO3 is shifted toward higher energy, whereas the pre-edge peak is slightly shifted to lower energy with increasing hydrostatic pressure. We provide spectral evidence for pressure-induced bandwidth broadening for mangnites. The enhanced intensity of the white line and the shifted absorption threshold of Mn K-edge spectra are explained in terms of a reduced JT distortion of MnO6 octahedra in compressed TbMnO3. Comparison of XAS data with full-multiple-scattering calculations using code FDMNES shows satisfactory agreement between experimental and calculated Mn K-edge spectra.
URI: http://dx.doi.org/10.1103/PhysRevB.79.165110
http://hdl.handle.net/11536/149781
ISSN: 1098-0121
DOI: 10.1103/PhysRevB.79.165110
期刊: PHYSICAL REVIEW B
Volume: 79
Issue: 16
起始頁: 0
結束頁: 0
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