Phase relations in the systems TiO2-IrO2 and SnO2-IrO2 in air

Abstract

The pseudobinary systems TiO2-IrO2 and SnO2-IrO2 were studied by x-ray diffraction after treatment at various temperatures in air. Their equilibrium phase diagrams were similar, with no intermediate phases detected in either system. Maximum solid solution of TiO2 occurs with the addition of about 5 mole percent IrO2 at 1040 °C. Solid solution of TiO2 in IrO2 extends to a maximum of about 12 mole percent TiO2 at 1040 °C, the dissociation temperature. Limited solid solubility of SnO2 in IrO2 exists up to 3 mole percent SnO2 at the dissociation temperature, 1025 °C. Solid solution in SnO2 was not detected at temperatures up to 1400 °C.