Phase equilibria in the system HfO2-ZrO2-CeO2 at 1500°C

Phase equilibria in the ternary system HfO2-ZrO2-CeO2 at 1500 °C are studied for the first time over the whole concentration range and an isothermal section of the phase equilibrium diagram at this temperature is constructed. Specimens of different compositions, synthesized from nitrate solutions by evaporation, drying, and heat treatment at 1500 °C, are studied by x-ray phase and petrographic analyses, and by electron microscopy. Three regions are established for solid solutions with a different extent based on different crystal modifications of the original components (M-HfO2, T-ZrO2, and F-CeO2), and three two-phase (T + F, T + M, F + M) and one three-phase (T + F + M) regions.