| Abstract Scope |
To evaluate the feasibility of physics-based third generation unary data and thermodynamic models in higher-order systems, Ga-Ni and Mn-Ni systems are successfully optimized using the descriptions for Ga, Ni, and Mn by considering contributions from lattice vibration, electronic excitation and magnetic ordering. The heat capacity of liquid-amorphous phases is modelled by the two-state model. More importantly, the high-temperature heat capacity of solid phases is directly extrapolated from the low-temperature one. To prevent solid phases from restabilizing under very high temperatures, the Equal Entropy Criteria is adopted. The improved magnetic model is adopted to calculate the magnetic properties and magnetic ordering energy. Meanwhile, to avoid nonzero entropy at 0 K, the temperature dependence of the interaction parameters for solution phases and formation energies for stoichiometric compounds is expressed by THETA parameter. The calculated phase diagram and thermochemical properties of Ga-Ni and Mn-Ni systems are in good agreement with experimental results. |