Thermodynamics and phase equilibria in the Al-In-Sb system

As part of a program for determination of the thermodynamic properties of the group III and V alloys and assessment of the phase equilibria, the activities of aluminum in the liquid Al-In-Sb system have been measured using a concentration cell of the type Al (1)/NaCl+KCl+3 mole pct $AlCl_3Al-In-Sb$ (1) The measurements are carried out along the constant compositional paths of $x_{Sb}=0.1$ and 0.2 over a temperature range of 1073 to 1273 K. The measured activity data in the system exhibit positive deviations from ideality. The deviations increase progressively with the In content of the alloys for a constant compositional path of Sb. The magnitude of the aAl as a function of In is found to decrease significantly with the increase in the Sb content of the alloys. The behavior is consistent with the existence of the liquid-liquid immiscibility in the syste