Experimental determination of the Phase Equilibrium of CaO-Ce2O3-SiO2-(5∼25 wt%) Al2O3 System at 1873K

The thermodynamic data of rare earth-containing systems are crucial for the development and application of permanent magnets, optoelectronic materials, high-temperature superconducting materials, and catalysts. In this study, the equilibrium phase compositions of the CaO-Ce 2 O 3 -SiO 2 -(5∼25 wt%) Al 2 O 3 system at 1873 K were investigated through high-temperature equilibrium experiments. The equilibrium phase compositions at 1873 K were determined using SEM, XRD, and EPMA, leading to the construction of isothermal sections. For the CaO-Ce 2 O 3 -SiO 2 -5 wt% Al 2 O 3 system, the isothermal cross-section diagram revealed a liquid phase region, four distinct two-phase equilibria, and two different three-phase equilibria. As the Al 2 O 3 content increased to 25 wt%, the isothermal cross-section diagram showed a liquid phase region, five different two-phase equilibria, and three distinct three-phase equilibria. The experimental results provide valuable insights for further research on the practical applications of cerium-containing rare earths in various fields.