Crystal structure and high-temperature properties of (Pr,Sr)2(Co,Mn)O4±δ with K2NiF4-type structure

• Published in: Solid state communications 2016-11, Vol.245, p.31-35
• Main Authors: Zharikova, E.V., Rozova, M.G., Kazakov, S.M., Istomin, S.Ya, Lyskov, N.V., Antipov, E.V.
• Format: Article
• Language: English
• Subjects: Crystal structure; Electrical conductivity; Oxides; Thermal expansion
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2016.07.020

Novel oxides PrSrCo1−yMnyO4±δ, 0.0≤y≤0.5 and Pr0.5Sr1.5Co1−yMnyO4±δ 0.3≤y≤0.5 with K2NiF4-type structure were synthesized. The crystal structure, oxygen content, thermal expansion and electrical conductivity of the obtained compounds were examined. A chemical titration showed that PrSrCo0.5Mn0.5O4±δ is slightly overstoichiometric (δ=0.03(2)), while Pr0.5Sr1.5Co0.5Mn0.5O4±δ is oxygen deficient (δ=−0.05(2)). Thermal expansion behavior was studied by both dilatometry and high-temperature X-ray powder diffraction in the temperature range of 298–1173K in air. Pr0.5Sr1.5Co0.5Mn0.5O3.95(2) exhibited linear thermal expansion along the a- and c-axes over the studied temperature range with thermal expansion coefficients (TECs) were 17.5ppmK−1 and 17.8ppmK−1, respectively. For PrSrCo0.5Mn0.5O4.03(2) two regions (298–600K and 600–1173K) observed, where the TEC along the a-axis decreased from 12.7ppmK−1 to 10.4ppmK−1 whereas the TEC along the c-axis increased from 14.5ppmK−1 to 26.7ppmK−1. Both compounds demonstrated lower in comparison with undoped PrSrCoO4 values of electrical conductivity of 7S/cm for PrSrCo0.5Mn0.5O4.03(2) and 23S/cm for Pr0.5Sr1.5Co0.5Mn0.5O3.95(2) at 1173K in air. •Novel oxides with K2NiF4 structure.•High-temperature thermal expansion behavior.•High-temperature electrical conductivity in air.