Počet záznamů: 1

Metal-insulator transition and the Pr.sup.3+./sup./Pr.sup.4.+./sup. valence shift in (Pr.sub.1-y./sub.Y.sub.y./sub.).sub.0.7./sub.Ca.sub.0.3./sub.CoO.sub.3./sub..

  1. 1.
    0352107 - FZU-D 2011 RIV US eng J - Článek v odborném periodiku
    Hejtmánek, Jiří - Šantavá, Eva - Knížek, Karel - Maryško, Miroslav - Jirák, Zdeněk - Naito, T. - Sasaki, H. - Fujishiro, H.
    Metal-insulator transition and the Pr3+/Pr4.+ valence shift in (Pr1-yYy)0.7Ca0.3CoO3.
    Physical Review. B. Roč. 82, č. 16 (2010), 165107/1-165107/7 ISSN 1098-0121
    Grant CEP: GA ČR GA202/09/0421
    Výzkumný záměr: CEZ:AV0Z10100521
    Klíčová slova: spin-state transition * magnetic-properties * crystal-field * transport * La1-xSrxCoO3
    Kód oboru RIV: BM - Fyzika pevných látek a magnetismus
    Impakt faktor: 3.772, rok: 2010

    The magnetic, electric, and thermal properties of the (Ln1-yYy0.7Ca0.3CoO3 perovskites (Ln=Pr,Nd) were investigated down to very low temperatures. The main attention was given to a peculiar metal-insulator (M-I) transition, which is observed in the praseodymium based samples with y=0.075 and 0.15 at TM-I=64 K and 132 K, respectively. The study suggests that the transition, reported originally in Pr0.5Ca0.5CoO3, is not due to a mere change in cobalt ions from the intermediate to the low-spin states but is associated also with a significant electron transfer between Pr3+ and Co3+ /Co4+ sites, so that the praseodymium ions occur below TM-I in a mixed Pr3+ /Pr4+ valence.
    Trvalý link: http://hdl.handle.net/11104/0191693