THERMODYNAMICS OF THE GA-SB SYSTEM DETERMINED BY VAPOR-PRESSURE MEASUREMENTS

on the basis of vapour pressure measurements by the Knudsen method, th e thermodynamic activity was determined for antimony in liquid Ga-Sb a lloys for concentrations ranging from 9.25 to 87.49 mole% of antimony and for the temperatures of 909 to 1161 K. Antimony activity shows mod erate negative deviation from the ideal solution behaviour. Model of t he ideal associated solution, with GaSb and Ga3Sb as associates, was u sed to describe antimony activity and subsequently to determine values of such thermodynamic functions as the molar heat content of the solu tion, and the standard molar Gibbs energy of formation of the GaSb(s), and to determine the phase diagram of the Ga-Sb system. The results o btained have been discussed and compared with available literature dat a.