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Valence shift of Pr ion from 3+ to 4+ in (Pr.sub.1-y./sub.Y.sub.y./sub.).sub.0.7./sub.Ca.sub.0.3./sub.CoO.sub.3./sub. estimated by X-ray absorption spectroscopy
- 1.0379116 - FZÚ 2013 RIV JP eng J - Journal Article
Fujishiro, H. - Naito, T. - Ogawa, S. - Yoshida, N. - Nitta, K. - Hejtmánek, Jiří - Knížek, Karel - Jirák, Zdeněk
Valence shift of Pr ion from 3+ to 4+ in (Pr1-yYy)0.7Ca0.3CoO3 estimated by X-ray absorption spectroscopy.
Journal of the Physical Society of Japan. Roč. 81, č. 6 (2012), "064709-1"-"064709-5". ISSN 0031-9015
R&D Projects: GA ČR(CZ) GAP204/11/0713
Institutional research plan: CEZ:AV0Z10100521
Keywords : Pr–Ca–Co–O * Pr valence shift * metal–insulator transition * XANES
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 2.087, year: 2012
The temperature dependence of the X-ray absorption near-edge structure (XANES) spectra at the Pr L3 edge was measured for the (Pr1-yYy)0.7Ca0.3CoO3 samples (y=0.075 and 0.15), in which a peculiar metal–insulator (MI)transition and a spin-state (SS) transition took place simultaneously at a critical temperature TMI. The valence states of praseodymium ion were determined using the analyses of XANES spectra. The results suggest that the average valence of the praseodymium ion increases below room temperature from the common value 3.0+, undergoes a steepest change at TMI, and reaches finally 3.15+ and 3.27+ at 8K for the y=0.075 and 0.15 samples, respectively.
Permanent Link: http://hdl.handle.net/11104/0210382
Number of the records: 1