Thermochemical properties of the intermetallic compounds in the lanthanum–cadmium system

Thermochemical properties on the intermetallic compounds in the lanthanum–cadmium (La–Cd) system were investigated electrochemically. The redox reactions of the La3+/La couple at the Cd-coated W electrodes, which were prepared by the electrodeposition of Cd at the W electrode, were studied by cyclic voltammetry and chronopotentiometry at 673, 723, 773, 823 and 873 K in the LiCl–KCl eutectic melts containing 1.2 wt% LaCl3. There were several cathodic and anodic peaks corresponding to the formation and the decomposition of the intermetallic compounds, LaCdx, respectively, in the cyclic voltammograms. Since the amount of Cd adsorbed on the W electrode could be evaluated during the electrochemical measurement, the compositions of all LaCdx could be analyzed exactly from the accumulated coulomb numbers of every anodic peak, which was attributed to the decomposition of each LaCdx. The formation energy of each LaCdx could be also estimated by chronopotentiometry.