Thermodynamic calculation of Ms in ZrO2–CeO2–Y2O3 system

The difference of Gibbs free energy between tetragonal and monoclinic phases in ZrO2–CeO2–Y2O3 as a function of composition and temperature is thermodynamically calculated from the three related binary systems. In 8 mol% CeO2–0.5 mol% Y2O3–ZrO2, the equilibrium temperature between tetragonal and monoclinic phases, T0, is obtained as 832.5 K and the Ms temperature of this alloy with a mean grain size of 0.90 μm is calculated as 249.9 K using the approach derived by Hsu et al. [J. Mater. Sci., 18(1983)3206; 20(1985)23; Acta Metall., 37(1989)3091; Acta Metall. Mater., 39(1991)1045; Mater. Trans. JIM, 37(1996)1284], which is in good agreement with the experimental one of 253 K.