Heat capacity for the Eu2Zr2O7 and phase relations in the ZrO2–Eu2O3 system: Experimental studies and calculations

Temperature dependence of heat capacity of the Eu2Zr2O7 and Y2O3 is measured in the temperature range of 298.15–1373 K by differential scanning calorimetry (DSC). Phase transformation in the Eu2Zr2O7 was experimentally studied using differential thermal analysis (DTA) up to 2173 K and temperature of pyrochlore to fluorite transition was established to be 2128 K. Eutectic reaction was determined by DTA to be 2326 K. Peritectoid reaction F + B = C was established to occur at ∼1823 K based phase equilibrium studies. Phase compositions were determined by SEM/EDX. The obtained results for heat capacity of the Eu2Zr2O7, temperatures of transformations and phase compositions were used to optimise thermodynamic parameters of the Eu2O3–ZrO2 system.

► Heat capacities of Eu2Zr2O7 and Y2O3 are measured by DSC. ► Phase transformations are investigated by DTA and phase equilibration. ► Phases are identified using XRD and SEM/EDX. ► Thermodynamic parameters of the ZrO2–Eu2O3 system are assessed and phase diagram is calculated.