DFT Calculations and Thermodynamic Re-Assessment of the Fe-Y Binary System

Based on the CALPHAD method combined with density functional theory (DFT) calculations, we performed a thermodynamic reassessment of the binary Fe-Y system leading to good agreement with the available experimental measurements. The electronic, vibrational, and magnetic contributions to the specific heat and thus the Gibbs free energy were evaluated based on accurate DFT calculations for the Fe-Y intermetallic compounds. Moreover, a new model was applied to describe the Gibbs free energies of such intermetallic phases which leads to significant improvements over the conventional thermodynamic expressions. The resulting phase diagram and thermodynamic properties are in good consistency with the previous experimental data, paving the way to designing multicomponent magnetic functional materials.