High-pressure Bi(Mg1 − xZnx)1/2Ti1/2O3 perovskite solid solutions

We report the preparation of Bi(Mg1 − xZnx)1/2Ti1/2O3 ceramics at a pressure of 6 GPa and temperatures from 1370 to 1570 K. In the composition ranges 0 < x < 0.5 and 0.8 < x < 1, the ceramics consist of perovskite solid solutions. The solid solutions with x < 0.5 have an orthorhombic structure (sp. gr. Pnnm), and those with x > 0.7 have a tetragonal structure (sp. gr. P4mn). On heating at atmospheric pressure, the solid solutions with 0.1 < x < 0.5 undergo an irreversible orthorhombic-to-rhombohedral (sp. gr. R3c) phase transition, accompanied by heat absorption and an increase in specific volume. The transition temperature decreases with increasing x. The reduced perovskite cell parameter of the solid solutions increases linearly with x. The Curie temperature of the rhombohedral solid solutions exceeds the decomposition temperature of the perovskite phase.