Thermochemical properties of some liquid III-V alloys

Heat contents of the Ga-P, In-P, Ga-As and In-As systems were measured by a drop-calorimeter in the respective concentration ranges of X_p = 0.02 to 0.1, X_p = 0.05 to 0.5, X_As = 0.05 to 0.5 and X_As = 0.05 to 0.5, and 1n the temperature ranges of 800 to 1550K. The enthalpies of fusion for InP, GaAs and InAs were determined as 44.09 ± 0.09, 53.36 ± 0.10 and 37.92 ± 0.14kJ g-atom^-, respectively, at the corresponding melting points of 1340 ± 1, 1514 ± 1 and 1221 ± 1K. A thermodynamic analysis method was applied to calculate thermodynamic quantities such as the Gibbs free energies of mixing in the liquid Ga-P, In-P, Ga-As and In-As systems. An optimization of experimental data for these systems were carried out, and the coefficients for the excess Gibbs free energies of mixing for the liquid phase were derived in this study.