Calcium-induced cation ordering and large resistivity decrease in Pr.sub.0.3./sub.CoO.sub.2./sub.

0466138 - FZÚ 2017 RIV GB eng J - Journal Article
Brázda, Petr - Palatinus, Lukáš - Drahokoupil, Jan - Knížek, Karel - Buršík, Josef
Calcium-induced cation ordering and large resistivity decrease in Pr_0.3CoO₂.
Journal of Physics and Chemistry of Solids. Roč. 96-97, Sep (2016), s. 10-16. ISSN 0022-3697. E-ISSN 1879-2553
R&D Projects: GA ČR GA13-03708S
Institutional support: RVO:68378271 ; RVO:61388980
Keywords : thermoelectric cobaltate * Pr_xCoO₂ * electron diffraction tomography * powder X-ray diffraction * cobalt oxide
Subject RIV: BM - Solid Matter Physics ; Magnetism; CA - Inorganic Chemistry (UACH-T)
Impact factor: 2.059, year: 2016

Structure of layered cobaltates Pr0.3CoO2 and (PrCa)0.3CoO2 were investigated by electron diffraction tomography and powder X-ray diffraction. The effect of the calcium substitution on thermoelectric properties was evaluated. The structure consists of hexagonal sheets of edge-sharing CoO6 octahedra interleaved by cationic monolayers. The cations form a 2-dimensional a√3×a√3 superstructure in the a–b plane. While Pr0.3CoO2 showed no layer order in the [001] direction, introduction of calcium resulted in the formation of a superstructure spanning over six cationic layers along the [001]. This superstructure model appears to be valid also for the description of the superstructures of CaxCoO2 and SrxCoO2 with x about 1/3.
Permanent Link: http://hdl.handle.net/11104/0264539