Abstract
High-temperature heat contensts of III-V compounds (III: Al, Ga, In V: N, P, As, Sb) were measured over the temperature range 650 to 1550 K using a drop-calorimeter. The heats of fusion of InP, GaAs, InAs, AlSb, GaSb and InSb were determined as 88.17±0.18, 106.72±0.20, 75.83±0.28, 82.48±0.31, 64.91±0.16, and 45.05±0.35 kJ/mol, respectively, at the corresponding melting points of 1340±1, 1514±1, 1221±1, 1327±2, 991±1, and 800±1 K. The heat content and the heat capacity equations were derived by the use of the Shomate function for the solid compounds and least-squares method for the liquid phases. Based on the third law method, Gibbs energy equations of formation were determined from the obtained heat capacity data and are tabulated per compound and per stable phase. The heats of fusion and the melting points of the compounds increase with increasing cohesive energy per bond while the entropies of fusion of the compounds increase with decreasing hybrid polarity.
