Structure and properties of novel cobaltates Ln.sub.0.3./sub.CoO.sub.2./sub. (Ln = La, Pr, and Nd)

0383726 - FZÚ 2013 RIV US eng J - Journal Article
Knížek, Karel - Jirák, Zdeněk - Hejtmánek, Jiří - Maryško, Miroslav - Buršík, Josef
Structure and properties of novel cobaltates Ln_0.3CoO₂ (Ln = La, Pr, and Nd).
Journal of Applied Physics. Roč. 111, č. 7 (2012), "07D707-1"-"07D707-3". ISSN 0021-8979. E-ISSN 1089-7550
R&D Projects: GA ČR GA203/09/1036; GA ČR GA202/09/0421
Institutional research plan: CEZ:AV0Z10100521; CEZ:AV0Z40320502
Keywords : thermoelectric and thermomagnetic effects * heat capacity * saturation moments and magnetic susceptibilities * nonmetals * Insulators * low-field transport
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 2.210, year: 2012

Layered cobaltates LnxCoO2 (Ln=La, Pr, Nd; x ~ 0.30), isostructural with well known thermoelectrics NaxCoO2, have been characterized by diffraction methods and probed by the electric transport, magnetic and heat capacity measurements. The thermopower increases with temperature and saturates above room temperature at a large value ~ 175 lV=K. The conductivity is affected by occupational disorder and follows Mott’s T-1/n law. The main attention is given to Pr0.3CoO2 and Nd0.3CoO2, in which the spins of hole carriers in the CoO2 layers coexist with localized magnetic moments of Pr3+ or Nd3+. The systems are found paramagnetic down to the lowest temperatures and behave accordingly to the non-Kramers or Kramers character of the rare earth ions.
Permanent Link: http://hdl.handle.net/11104/0213576