Activity measurement of liquid Zn-In and Cd-In alloys by an EMF method using zirconia electrolyte

The emf values obtained for both systems showed a good stability with time and linear relationships with temperature. The activities of the components in the Zn-In alloys at 900 and 1000 K and in the In-Cd alloys at 850 and 900 K exhibit moderately positive deviations from Raoult's law over the entire concentration ranges, respectively. The activities of zinc and indium in the liquid Zn-In alloys were evaluated in a higher temperature range than those in the published data. Considering the temperature dependence, the positive deviations of activities from Raoult's law in the Zn-In alloys are a little smaller than the previous values. The published data on the activities of indium of the liquid In-Cd alloys have been derived from the activities of cadmium based on a Gibbs-Duhem integration. In this study, the activities of indium of the In-Cd alloys are measured by a direct method. The behavior of activities of the In-Cd alloys in this study is similar to the previous data. The activity values of indium are in good agreement with the result by Heumann et al. The activities of the components in the Zn-In alloys show reasonably greater positive deviations than those in the In-Cd alloys, owing to the larger differences of atomic radius factor in the Zn-In alloys.