 |
Journal articles
Phase equilibria, crystal structure and properties of complex oxides in the Nd2O3-SrO-CoO system
Abstract : The phase equilibria in the 1/2Nd(2)O(3)-SrO-CoO system were systematically studied at 1373 K in air. The intermediate phases formed in the 1/2Nd(2)O(3)-SrO-CoO system at 1373 K in air are Nd1-xSrxCoO3-delta (0.0 <= x <= 0.5 with orthorhombic structure, sp. gr. Pbnm and 0.6 <= x <= 0.95 whose structure was detected as cubic according to XRD sp. gr. Pm3m, but shown to be tetragonal by TEM due to the oxygen vacancy ordering), Nd2-ySryCoO4-delta (0.6 <= y <= 1.1 with tetragonal K2NiF4-type structure, sp. gr. I4/mmm) and Nd2-zSrzO3 (0.0 <= z <= 0.15 with hexagonal structure, sp. gr. P-3m1). The unit cell parameters for the single phase samples were refined by the Rietveld analysis. The changes of oxygen content in Nd1-xSrxCoO3-delta (0.6 <= x <= 0.95) and Ruddlesden-Popper oxide Nd2-ySryCoO4-delta were examined by TGA. All were found to be oxygen deficient phases. High-temperature dilatometry allows calculating the thermal expansion coefficient and evaluating the chemical expansion coefficient at high temperature. The projection of isothermal-isobaric phase diagram for the Nd-Sr-Co-O system at 1373 K in air to the compositional triangle of metallic components has been constructed. The phase equilibria in the studied Nd-Sr-Co-O system were compared to La-Sr-Co-O and Nd-M-Co-O (M=Ca and Ba).
https://hal-normandie-univ.archives-ouvertes.fr/hal-02175433
Contributor : Elisabeth van T Hof Connect in order to contact the contributor
Submitted on : Friday, July 5, 2019 - 5:01:49 PM
Last modification on : Friday, January 7, 2022 - 3:53:40 AM
Contributor : Elisabeth van T Hof Connect in order to contact the contributor
Submitted on : Friday, July 5, 2019 - 5:01:49 PM
Last modification on : Friday, January 7, 2022 - 3:53:40 AM
