Modeling of Phase Equilibria in the La2O3–SrO–ZrO2 System Using the NUCLEA Database

Abstract

The goal of this work was to study phase equilibria in the La₂O₃–SrO–ZrO₂ system, which is a promising base for high-temperature ceramics and materials with unique optical, electrochemical, and catalytic properties. Thermodynamic modeling of phase equilibria in this system was carried out using the NUCLEA database and GEMINI2 (Gibbs Energy Minimizer) software. One polythermal and thirteen isothermal sections of the La₂O₃–SrO–ZrO₂ phase diagram were calculated in the temperature range 600–3023 K. The obtained data on La₂O₃–SrO–ZrO₂ phase equilibria were discussed with reference to information available on the corresponding binary systems. The modeled phase relations in the ternary system under study correlate completely with the phases existing in the corresponding binary systems. The temperature evolution of the phase relations and boundaries of single-phase, two-phase, and three-phase areas in the system were considered. Four ternary eutectic points were identified at 2039, 2105, 2120, and 2351 K.