Study on the structural and electrical properties of Sr1−xCexMnO3−α (x = 0.1, 0.3) perovskite oxide

We found that the partial substitution of Ce for Sr in SrMnO3 could stabilize the perovskite-type structure and made the conductivity increase. In the present study, the structural and electrical properties of Sr0.9Ce0.1MnO3−α were investigated by referring to those of Sr0.7Ce0.3MnO3−α·Sr0.9Ce0.1MnO3−α showed the first-order transition from tetragonal to cubic at about 55°C, at which a drastic change in the conductivity occurred. Above this temperature, the conductivity became very high, about 450 S·cm−1 at 150°C and 270 S·cm−1 at 800°C. In contrast, Sr0.7Ce0.3MnO3−α did not exhibit a drastic phase transition like that in the case of Sr0.9Ce0.1MnO3−α. The thermal expansion rate of Sr0.9Ce0.1MnO3−α was influenced by the phase transition, but the displacement observed by thermo-mechanical analysis (TMA) was slight at the phase transition temperature. The chemical compatibility of Sr0.9Ce0.1MnO3−α with CeO2-based solid electrolyte was quite good at the fabrication temperature.