Phase equilibria of the image system

A thermodynamic description for the TiO2–Y 2O3 system is performed by considering reliable literature data and newly measured phase equilibria. Using X-ray diffraction, the phase composition range and the decomposition temperature of fluorite are detected. The present description of the TiO2–Y 2O3 system yields a set of critical thermodynamic parameters as well as the complete TiO2–Y 2O3 phase diagram. Comparison between the calculated and measured phase equilibria in the TiO2–Y 2O3 system shows that the experimental information is satisfactorily accounted for and some new equilibria at higher temperature are predicted by the present calculation.