The perovskite oxide system Pr1-xSrxCo1-yMnyO3-δ crystal structure and thermal expansion

The crystal structure and thermal expansion of the perovskite oxides in the system Pr1-xSrxCo1-yMnyO3-delta (x = 0.3, 0.5, y = 0-1) were studied in air. All compositions have an orthorhombic GdFeO3-type structure (Pbnm space group). The lattice parameters were determined at room temperature. The pseudo-cubic lattice constant decreased on increasing the Co content, while the thermal expansion coefficient increased as the Co content of the oxides increased for both series with 30 and 50 mol% Sr. Among the Co-containing compositions, those with 20 mol% Co exhibited thermal expansion compatibility with Ce0.9Gd0.1O1.95 electrolyte in the whole examined temperature range (room temperature to 800 C). They can be considered, therefore, as candidate cathode materials for intermediate temperature solid oxide fuel cells. 21 refs.