Thermodynamic description of the La-Co-Fe and Ce-Co-Fe ternary systems

Based on the available experimental data reported in the literature, the La-Co and Ce-Co binary systems were reassessed thermodynamically using the CALPHAD method in this work. The calculated phase diagrams and thermodynamic properties of the La-Co and Ce-Co binary systems are well consistent with the experimental results. Furthermore, the La-Co-Fe and Ce-Co-Fe ternary systems were calculated by combining the re-assessed La-Co and Ce-Co binary systems in this work with the previous assessments of the La-Fe, Ce-Fe and Co-Fe binary systems. The calculated liquidus projections, isothermal sections and vertical sections in the La-Co-Fe and Ce-Co-Fe ternary systems are in good agreement with the experimental results. The reasonable thermodynamic parameters of the La-Co-Fe and Ce-Co-Fe ternary systems were obtained in this work, which would be fundamental to developing a thermodynamic database of the multi-component RE-TM-Fe alloy systems, and then to designing novel RE2Fe17-xTMx magnets with light rare-earth metals La and Ce.