Simultaneous valence shift of Pr and Tb ions at the spin-state transition in (Pr.sub.1-y./sub.Tb.sub.y./sub.).sub.0.7./sub.Ca.sub.0.3./sub.CoO.sub.3./sub..

0422574 - FZÚ 2014 RIV US eng J - Journal Article
Fujishiro, H. - Naito, T. - Takeda, D. - Yoshida, N. - Watanabe, T. - Nitta, K. - Hejtmánek, Jiří - Knížek, Karel - Jirák, Zdeněk
Simultaneous valence shift of Pr and Tb ions at the spin-state transition in (Pr_1-yTb_y)_0.7Ca_0.3CoO₃.
Physical Review. B. Roč. 87, č. 15 (2013), "155153-1"-"155153-7". ISSN 1098-0121
R&D Projects: GA ČR(CZ) GAP204/11/0713
Institutional support: RVO:68378271
Keywords : metal-insulator transitions and other electronic transitions * X-ray absorption spectra * spin crossover
Subject RIV: BE - Theoretical Physics
Impact factor: 3.664, year: 2013

Temperature dependence of the x-ray absorption near-edge structure (XANES) spectra at the Pr L3 and Tb L3 edges was measured for the (Pr1-yTby )0.7Ca0.3CoO3 system, in which a sharp spin-state (SS) transition took place at a critical temperature TSS. A small increase in the valence of the terbium ion was found below TSS, besides the enhancement of the praseodymium valence; the trivalent states, which are stable at room temperature, change to a 3+/4+ ionic mixture at low temperatures. In particular for the y = 0.2 sample, the average valence determined at 8 K amounts to 3.25+ and 3.03+ for the Pr and Tb ion, respectively.
Permanent Link: http://hdl.handle.net/11104/0228714