Počet záznamů: 1  

Magnetism and transport properties of layered rare-earth cobaltates Ln.sub.0.3./sub.CoO.sub.2./sub

  1. 1. 0447812 - FZU-D 2016 RIV US eng J - Článek v odborném periodiku
    Knížek, Karel - Novák, Pavel - Jirák, Zdeněk - Hejtmánek, Jiří - Maryško, Miroslav - Buršík, Josef
    Magnetism and transport properties of layered rare-earth cobaltates Ln0.3CoO2
    Journal of Applied Physics. Roč. 117, č. 17 (2015), "17B706-1"-"17B706-4" ISSN 0021-8979
    Grant CEP: GA ČR GA13-03708S
    Institucionální podpora: RVO:68378271 ; RVO:61388980
    Klíčová slova: crystal field * rare earth cobaltates * magnetism and transport properties
    Kód oboru RIV: BM - Fyzika pevných látek a magnetismus
    Impakt faktor: 2.101, rok: 2015

    The ab-initio (GGA+U) electronic structure calculations of layered cobaltates Ln0.3CoO2 (Ln = La, Pr, Nd) prepared by ionic exchange from Na 0.90CoO2 precursors have been performed. The data are used for numerical modeling of Seebeck coefficient within Boltzmann transport theory using BoltzTraP program [G. K. H. Madsen and D. J. Singh, Comput. Phys. Commun. 175, 67 (2006)], as well as for determination of the crystal field split levels of rare-earth ions using a method based on a transformation of Bloch states into the basis of Wannier functions [P. Novák et al., Phys. Rev. B 87, 205139 (2013)]. An overall agreement with observed magnetism and transport properties is obtained. In particular, the high p-type thermopower is well reproduced in a broad temperature range, but instead of theoretical linear decrease down to the lowest temperatures, the real systems exhibit an anomalous change of Seebeck sign.
    Trvalý link: http://hdl.handle.net/11104/0249593