Experimental investigation and thermodynamic evaluation of the ZrO2–TiO2–SrO system

In the present work, a series of ZrO2–TiO2–SrO ceramic samples were prepared through solid-state reactions, and the phase relationships at 1473 K were systematically characterized. For the TiO2–SrO binary system, the presence of Sr4Ti3O10 was confirmed and the binary system was reassessed through CALPHAD method by using both the latest experimental data and first-principles calculations. The thermodynamic parameters of the TiO2–SrO system were combined with those of the ZrO2–TiO2 and ZrO2–SrO systems, and a set of self-consistent thermodynamic parameters of the ZrO2–TiO2–SrO system was optimized according to our measurements. Finally, the isothermal sections at 1473 K and 1733 K, the vertical section of SrTiO3–SrZrO3 and the liquidus surface projection were calculated. The calculated results agree well with the available experimental data, which proves the self-consistency and reliability of the present thermodynamic database.