Thermodynamic properties of the Na–Bi–Pb system

Thermodynamic properties of Na in an equimolar Bi–Pb alloy were determined at 723 K for compositions of 0.0075 ≤ XNa ≤ 0.1000 from electromotive force measurements on Na metal concentration cells with a solid Na–β-Al2O3 electrolyte. A coulometric titration technique was used to electrochemically generate the Na metal in the Bi–Pb alloy. The results indicate that, as Na is added to Bi–Pb, the liquid becomes more associated and suggests complex species formation with an ionic character intermediate between those observed for the constituent binaries.