Revised Phase Diagram of the System ZrO₂‐CeO₂ Below 1400°C

The phase diagram of the system ZrO₂‐CeO₂ was rein‐vestigated using hydrothermal techniques. Cubic, tetragonal, and monoclinic solid solutions are present in this system. The tetragonal solid solution decomposes to monoclinic and cubic solid solutions by a eutectoid reaction at 1050°50°C. The solubility limits of the tetragonal and cubic solid solutions are about 18 and 70 mol% CeO₂, respectively, at 1400°C, and about 16 and 80 mol% CeO₂, respectively, at 1200°C. Solubility limits of the monoclinic and cubic solid solutions are about 1.5 and 88 mol% CeO₂ at 1000°C, and 1.5 and 98 mol% CeO₂ at 800°C, respectively. The compound Ce₂Zr₃O₁₀ is not found in this system.