Evaluation of Gibbs free energies of formation of Ce–Cd intermetallic compounds using electrochemical techniques

• Gibbs free energies of formation of six Ce–Cd intermetallic compounds were evaluated.
• Electrochemical measurements were performed from 673 to 923 K.
• Extrapolating to higher temperature gives a useful data set for Cd-distillation step.

Gibbs free energies of formation of six Ce–Cd intermetallic compounds, CeCd, CeCd2, CeCd3, CeCd58/13, CeCd6 and CeCd11, were evaluated systematically using electrochemical techniques in the temperature range of 673–923 K in the LiCl–KCl–CeCl3–CdCl2 molten salt bath. The linear dependence of the Gibbs free energies of formation on temperature yields to the enthalpies and entropies of formation of these intermetallic compounds. By extrapolating the Gibbs free energy of Ce–Cd intermetallic compounds to the Cd distillation temperature, it was clear that the Gibbs free energy of Ce–Cd intermetallic compounds decreases gradually from CeCd6 to CeCd2 and attains minimum value at CeCd2. This suggests on the Cd distillation from the U–Pu–Ce–Cd alloy that the dissolution of U or Pu into CeCd2 should be mostly taken into consideration.