Charge transfer, valence, and the metal-insulator transition in Pr.sub.0.5./sub.Ca.sub.0.5./sub.CoO.sub.3./sub..

0353284 - FZÚ 2011 RIV US eng J - Journal Article
Knížek, Karel - Hejtmánek, Jiří - Novák, Pavel - Jirák, Zdeněk
Charge transfer, valence, and the metal-insulator transition in Pr_0.5Ca_0.5CoO₃.
Physical Review. B. Roč. 81, č. 15 (2010), 155113/1-155113/5. ISSN 1098-0121
R&D Projects: GA ČR GA202/09/0421
Institutional research plan: CEZ:AV0Z10100521
Keywords : Pr_0.5Ca_0.5CoO₃ * GGA+U calculations * metal-insulator transition * spin transitions
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 3.772, year: 2010

Generalized gradient approximation (GGA) +U electronic-structure calculations evidence that the recently observed simultaneous metal-insulator and spin-state transition in perovskite cobaltite Pr0.5Ca0.5CoO3 is accompanied by a charge transfer between Pr and Co cations from 0.5 Pr3+ + Co3.5+ toward 0.5 Pr4+ + Co3+. The metal-insulator transition is a result of the interplay between covalency of the Pr-O bond and increasing stability of the insulating low-spin configuration with decreasing valency of Co cation. Our calculations explain why this type of transition is encountered in the Pr-based system only.
Permanent Link: http://hdl.handle.net/11104/0192573