Cobalt Gallium system is a border of some ternary systems interesting for opto-electronics. Gallium arsenide, gallium antimonide gallium nitride and their alloys are well-known materials for such applications. Ohmic contacts with high thermal stability, doping and band engineering by alloying semi-conductors are very important in microelectronic technology. They are sometimes difficult to prepare. The phase relationship and thermodynamics properties of metal-semi-conductor materials are very useful in preventing material modifications. The present study, related to Cobalt-III-V systems, is made in that objective.
The thermochemistry of the face centered cubic (fcc), liquid and two compounds, namely the b and CoGa3 in this system, have been systematically studied in the past, and the equilibrium phase diagram of this binary system has been determined experimentally.
A thermodynamic assessment was conducted using experimental data on the phase boundaries of the Co–Ga system and other related thermochemical properties. In addition, the experimental data of vacancy concentration of the b phase were incorporated. In this analysis, the intermetallic b phases was described using the sublattice model (Co,Ga)0.5(Co,Va)0.5. The CoGa3 phase is a stoichiometric compound. There is a good agreement between the calculated and the experimental phase boundaries, and the thermodynamic properties and vacancy concentrations of the b phase were reproduced satisfactorily.