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-y MnyO3-delta (x = 0.3, 0.5, 0 less than or equal to y less than or equal to 1) were studied in air, by X-ray powder diffraction and dilatometry, respectively. All compositions have an orthorhombic GdFeO3-type structure (Pbnm space group). The lattice parameters were determined at room temperature. The pseudo-cubic lattice constant decreases on increasing Co content. The thermal expansion coefficient increases as the Co content of the oxides increases for both series with 30 and 50 mol% Sr. Among the Go-containing compositions, those with 20 mol% Co exhibit thermal expansion compatibility with Ce0.9Gd0.1O1.95 electrolyte in the whole examined temperature range (room temperature to 800 degrees C). They can be considered, therefore, as candidate cathode materials for intermediate temperature solid oxide fuel cells. (C) 1998 Elsevier Science Limited. All rights reserved.