Phase transition in Pr.sub.0.5./sub.Ca.sub.0.5./sub.CoO.sub.3./sub. and related cobaltites

0423009 - FZÚ 2014 RIV DE eng J - Článek v odborném periodiku
Hejtmánek, Jiří - Jirák, Zdeněk - Kaman, Ondřej - Knížek, Karel - Šantavá, Eva - Nitta, K. - Naito, T. - Fujishiro, H.
Phase transition in Pr_0.5Ca_0.5CoO₃ and related cobaltites.
European Physical Journal B. Roč. 86, č. 7 (2013), "305-1"-"305-8". ISSN 1434-6028. E-ISSN 1434-6036
Grant CEP: GA ČR(CZ) GAP204/11/0713
Institucionální podpora: RVO:68378271
Klíčová slova: perovskites * cobaltites * electrotransport * thermal transport
Kód oboru RIV: BM - Fyzika pevných látek a magnetismus
Impakt faktor: 1.463, rok: 2013

Presented magnetic, electric and thermal meas.incl. X-ray absorption spectra of the Pr0.5.Ca0.5.CoO3 and (Pr1-yYy)0.7Ca0.3CoO3(y = 0.0625-0.15) perovskites, with a M-I transition, where structural and magnetic anomalies at 76 K and 40-132 K appeared. The inspection of the M-I transition using the XANES data of Pr-L3-edge and Co-K-edge proofs the presence of Pr4+ ions at low temperatures and indicates simultaneously the intermediate spin to low spin crossover of Co species on lowering the temperature. The study thus definitively confirms the synchronicity of the electron transfer between Pr3+ ions and Co3+/4+O3 subsystem and the transition to the low-spin, less electrically conducting phase.
Trvalý link: http://hdl.handle.net/11104/0229109