Thermodynamic properties of liquid magnesium-bismuth alloys

Thermodynamic properties of liquid Mg-Bi alloys have been determined, employing galvanic formation and concentration cells. There was a fairly good agreement between data obtained by the two different types of cells. The partial thermodynamic functions exhibit a marked deviation from ideality, which has been interpreted as a consequence of the stable compound Mg₃Bi₂ being formed in the system. The experimental data have been treated according to Krupkowski to give equations for the activity coefficients of magnesium and bismuth. From these equations, together with phase diagram data, the Gibbs free energy of formation of solid Mg₃Bi₂ has been evaluated. A similar treatment also has been applied to literature data for the corresponding Mg-Sb system.