Phase Equilibrium Investigations and Thermodynamic Study of the Y2O3-Ta2O5 System

Two methods were used to investigate the Y2O3-Ta2O5 system: the equilibration method, which covered temperatures from 1573 to 1973 K, and the DTA method, which reached up to 2473 K. Phase identification was carried out using x-ray diffraction and scanning electron microscopy with energy-dispersive x-ray spectroscopy (SEM/EDX). The temperature of the eutectic reaction, L → YTa3O9 (P) + Ta2O5, was determined to be 2019 K, with the corresponding eutectic composition being 78 mol.