Subsolidus Phase Relationship in the CaO–CuO–TiO2 Ternary System at 950°C in Air

The subsolidus phase relationship in the CaO–CuO–TiO2 ternary system at 950°C in air was investigated. Total 26 samples having various nominal compositions were prepared by the solid-state reaction at 950°C in air, and their equilibrium phases were analyzed by powder X-ray diffraction (XRD). The CaCu3Ti4O12 phase exhibits variable stoichiometry and forms as the Ca1−xCu3+xTi4O12-type (−0.019 ≤x ≤0.048) solid solution at 950°C in air. On the basis of our results and previous reports on the binary phase diagrams, the subsolidus phase diagram of the CaO–CuO–TiO2 ternary system could be constructed at 950°C in air.