Modeling of the Phase Equilibria in the La<sub>2</sub>O<sub>3</sub>–SrO–ZrO<sub>2</sub> System Using the NUCLEA Database

The goal of this study was to examine the phase equilibria in the La2O3–SrO–ZrO2 system, which is promising as a base for the development of high-temperature ceramics and materials with unique optical, electrochemical, and catalytic properties. Thermodynamic modeling of the phase equilibria in the system under consideration was carried out using the NUCLEA database and the GEMINI2 Gibbs energy minimizer. As a result, thirteen isothermal and one polythermal sections of the phase diagram of the La2O3–SrO–ZrO2 system were calculated in the temperature range 600-3023 K. The obtained data on the phase equilibria in the La2O3–SrO–ZrO2 system were discussed in comparison with the known information for the corresponding binary systems. The phase relations in the system under study were shown to correlate completely with the presence of the phases present in the corresponding binary systems. Temperature changes in the phase relations and boundaries of single-phase, two-phase, and three-phase regions in the system under study were considered. Four ternary eutectic points were identified at the temperatures equal to 2039 K, 2105 K, 2120 K, and 2351 K.