CHEMICAL INTERACTIONS BETWEEN LA-SR-MN-FE-O-BASED PEROVSKITES AND YTTRIA-STABILIZED ZIRCONIA

Orthoferrite-based perovskites are of interest as materials for the ca thode in solid oxide fuel cells (SOFCs). Therefore, the chemical compa tibility between perovskites of the composition (La1-xSrx)(z)Fe1-yMny O3-delta (O less than or equal to x less than or equal to 0.3; 0.2 les s than or equal to y less than or equal to 1; z = 0.90, 0.95, 1.00) an d the solid electrolyte zirconia (ZrO2) doped with 8 mol% yttria (Y2O3 ) (8YSZ) has been investigated, Powder mixtures of the two materials h ave beers annealed at different temperatures, The formation of monocli nic ZrO2 at 1000 degrees C, as well as of La2Zr2O7 and SrZrO3 at 1400 degrees C, has been determined in some samples. The reactions that are observed are discussed, with respect to the thermodynamic activities, tolerance factor, and oxygen-ion migration energies. Some perovskite compositions seem to be compatible with Y2O3-stabilized ZrO2 (YSZ), th ereby offering the possibility to use orthoferrite-based perovskites i n SOFCs with a solid electrolyte made of YSZ.