Thermodynamic assessment of BaO–Ln₂O₃ (Ln = La, Pr, Eu, Gd, Er) systems

Abstract

Heat capacities and enthalpies of formation of BaGd2O4 were determined by high‐temperature differential scanning calorimetry and high‐temperature oxide melt solution calorimetry, respectively. Thermodynamic stability of BaLn2O4 compounds increases with decreasing Ln3+ ionic radius. Previously reported data on BaNd2O4 and BaSm2O4 corroborate this trend. Missing data for compounds in BaO–Ln2O3 (Ln = La, Pr, Eu, Er) systems were estimated from established relations, thermodynamic assessment was performed, and binary phase diagrams were calculated.

Thermal Analysis of High Entropy Rare Earth Oxides

“…It is based on his 2007 assessments of thermodynamic properties of pure rare earth sesquioxides from room temperature to the melting point. This database is often used as a starting point for the creation of new thermodynamic assessments for systems with rare earth oxides [ 77 , 78 ]. Without any modifications, the database allows modeling of phase equilibria using the ideal solution model (which assumes zero enthalpies of mixing and the largest configurational entropy gains).…”