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Transition from the diamagnetic insulator to ferromagnetic metal in La.sub.1-x./sub.Sr.sub.x./sub.CoO.sub.3./sub..
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SYSNO ASEP 0353298 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title Transition from the diamagnetic insulator to ferromagnetic metal in La1-xSrxCoO3. Author(s) Knížek, Karel (FZU-D) RID, ORCID
Jirák, Zdeněk (FZU-D) RID, ORCID, SAI
Hejtmánek, Jiří (FZU-D) RID, ORCID
Novák, Pavel (FZU-D) RID, ORCIDSource Title Journal of Magnetism and Magnetic Materials. - : Elsevier - ISSN 0304-8853
Roč. 322, 9-12 (2010), s. 1221-1223Number of pages 3 s. Language eng - English Country NL - Netherlands Keywords LnCoO3 ; GGA+U calculation ; spin states transition Subject RIV BM - Solid Matter Physics ; Magnetism R&D Projects IAA100100611 GA AV ČR - Academy of Sciences of the Czech Republic (AV ČR) CEZ AV0Z10100521 - FZU-D (2005-2011) UT WOS 000275746100049 DOI 10.1016/j.jmmm.2009.04.031 Annotation We have analyzed, using the theoretical GGA+U calculations, different configurations of spin states (LS, IS and HS Co3+) and proposed a model that accounts for magnetic and electric transport properties of perovskite cobaltites upon doping by charge carriers. In particular, it appears that the compositional transition from the diamagnetic LS phase of LaCoO3 to the ferromagnetic metallic IS phase in La1-xSrxCoO3 (x > 0.2) involves the same mechanisms as the high-temperature transition in pure LaCoO3. The process occurs gradually via a phase-separated state, where metallic IS domains stabilized through a charge transfer between Co4+ and Co3+ neighbors coexist with the Co4+ poor regions in the LS ground state (or, at higher temperatures, in mixed LS/HS state). This phase separation vanishes when doping in La1-xSrxCoO3 reaches x ~ 0.2, and a uniform IS phase, analogous to that in pure LaCoO3 in the high-temperature limit, is established. Workplace Institute of Physics Contact Kristina Potocká, potocka@fzu.cz, Tel.: 220 318 579 Year of Publishing 2011
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