Activities of Gallium and Bismuth in Liquid Gold Base Binary Alloy Systems

Abstract

The values of E.M.F. of liquid Au-Ga and Au-Bi systems were measured in the temperature ranges from 670 to 820°C and 670 to 850°C by using galvanic cells composed of(This article is not displayable. Please see full text pdf.) \ oindentrespectively.The values of E.M.F. obtained for the Au-Bi system showed a good stability and a linear relationship with temperature.While the values obtained for the Au-Ga system were somewhat unstable and showed less reliability than those for the Au-Bi system.The activities of both components for the Au-Ga system demonstrate a considerable negative deviation from Raoult’s law over the whole concentration range. As for the Au-Bi system the activities of both components show a slight negative deviation from Raoult’s law over the entire range of concentration.The maximum values of the heat of mixing are −2.20 kcal/mol for the Au-Ga system at NGa=0.48 and −0.18 kcal/mol for the Au-Bi system at NBi=0.55.The activity coefficients of gallium in the liquid Au-Ga alloys are represented by the relation(This article is not displayable. Please see full text pdf.) \ oindentIntegration of the Gibbs-Duhem equation yields the relation(This article is not displayable. Please see full text pdf.) \ oindentConsequently, the excess molal free energy of mixing is given by the relation(This article is not displayable. Please see full text pdf.)