Thermodynamic description of the Gallium-Lanthanum binary system

Until now, no thermodynamic calculation has been done for the Ga-La system In the present work, it has been evaluated by means of the Calphad approach The solution phases (Liquid, (αLa), (βLa) and (γLa)) were modelled with the sublattice formalism and the excess term of the Gibbs energy with the Redlich-Kister equation. The intermetallic compound Ga2La which has a homogeneity range, was treated as the formula (Ga)0.667 (Ga,La)0.333 by a two-sublattice model with Ga on the first sublattice and Ga and La on the second one. Ga6La, Ga4La, GaLa, Ga3La5, GaLa3 have been treated as stoichiometric compounds. The calculated phase diagram and the thermodynamic properties of the system are in satisfactory agreement with the experimental data

Thermodynamic description of the Ga-Yb binary system

Pure gallium metal and many gallium based alloys and intermetallic compounds have extensive technological applications and fundamental interest. Gallium is used as a doping component in electronic devices (as in transistors or photovoltaic cells) [1]. The development of multi-alloy material depends nowfor most of them on preliminary numerical simulations. Such simulations are only useful when accurate thermodynamic databases are available. Such databases are developed by the CALPHAD (CALculation of PHAse Diagram) method on a basis of experimental thermodynamic and phase diagram measurements. The excess term of the Gibbs energy of the liquid phase was assessed with the recent exponential temperature dependence of the interaction energies by Kaptay [2–4] and compared with the Redlich-Kister [5] polynomial equation results. The calculations based on the thermodynamic modelling and optimisation are in good agreement with the phase diagram data availablein the literature

Thermodynamic modelling of the La-Pb Binary system

The thermodynamic modelling of the La-Pb binary system was carried out with the help of CALPHAD (CALculation of PHAse Diagram) method. La5Pb3, La4Pb3, La5Pb4, αLa3Pb4, βLa3Pb4, LaPb2, LaPb3 have been treated as stoichiometric compounds while a solution model has been used for the description of the liquid, BCC and FCC phases. The calculations based on the thermodynamic modeling are in good agreement with the phase diagram data and experimental thermodynamic values