Homogeneity Region of Strontium‐ and Magnesium‐Containing LaGaO ₃ at Temperatures between 1100° and 1500°C in Air

Abstract

Phase stability studies were performed within the quasi‐ternary system LaGaO 3 ‐SrGaO 2.5 ‐“LaMgO 2.5 ”. Emphasis was cast on the temperature dependence of the homogeneity region of La 1− x Sr x Ga 1− y Mg y O 3−δ perovskite solid solutions. Isothermal sections were determined at 1100°, 1250°, 1400°, and 1500°C in a static air atmosphere. The single‐phase homogeneity region was found to considerably diminish with decreasing temperature, indicating a reduction of the solid solubility of Sr and Mg, and below 1100°C the doped perovskite becomes unstable. Consequently, the cubic perovskite phase was found to exist only at elevated temperatures and for high Sr and Mg amounts. Sample preparation was performed by the mixed‐oxide process as well as by a modified combustion synthesis.