Measurement of activity of gallium in liquid Ga-In-Bi alloys using stabilized zirconia as the solid electrolyte

EMF of galvanic cells with stabilized zirconia solid electrolyte was measured to determine the activity of gallium in liquid Ga-In-Bi alloys in the temperature range from 1050 to 1200 K along three pseudobinary lines of (InyBi1-y)-Ga where y = 0.25, 0.50 and 0.75. A mixture of Ga and Ga2O3 was used as the reference electrode. The activity curves of Ga show positive deviations from ideality in the whole composition range. Iso-activity curves at 1073 K in the ternary Ga-In-Bi alloys were derived by combining the results of this study with activity data for Ga-In and Ga-Bi alloys. The iso-activity curves display small waves, and have concave curvatures in the Ga-rich region at lower temperatures. Using Darken's equation, data for two binary systems Ga-In and Ga-Bi, and ternary data determined in this study, Delta G(XS) at 1073 K was derived. The results are compared with those from the general model calculation proposed by Chou.