Determination of the component activities in the system In--Ga using a solid oxide electrolyte technique

An electrolytic technique utilizing the cell, , calcia stabilized , , has been used to measure activities of Ga in liquid In‐Ga alloys in the temperature range 800°–950°C. The Ga activities and the In activities, calculated from the Gibbs‐Duhem equation, show modest positive deviation from Raoult's law. The activities are compared with previously measured and computed values. The parameter (defined by ) is seen to have a very small composition dependence in the temperature range studied. The partial molar excess entropies of solution of Ga, calculated using the measured free energies and previously measured values for the heats of mixing, are demonstrated to be negative and small.