Thermodynamics of the Ga-Sb System Determined by Vapour Pressure Measurements

Abstract

On the basis of vapour pressure measurements by the Knudsen method the thermodynamic activity was determined by antimony in liquid Al-Sb alloys for concentrations ranging from 2.64 to 98.58 mole% of antimony and for temperatures of 950 to 1461 K. Antimony activity shows a moderate negative deviation from the ideal solution behaviour. A regular associated solution model incorporating the volume effect, with AlSb as the associate, was used to describe antimony activity and subsequently to determine values of such thermodynamic functions as molar enthalpy of mixing of liquid alloys, the standard molar Gibbs energy of formation and the enthalpy of melting of AlSb(s), and to determine the phase diagram of the Al-Sb system. The results obtained have been discussed and compared with available literature data.