Electrochemical Study on Formation of Dy-Ni Alloy in Molten Chlorides

The cyclic voltammetry, electrode potential-time curve after potentiostatic electrolysis, potential-step method and x-ray diffraction were used to study the electrochemical reaction of Dy (III) in NaCl-KCl equimolar mixture on Ni electrode. The DyNi sub 5 forms at first and then the intermetallic compounds of Dy-Ni containing more Dy form in sequence. The metallic Dy deposits at last. The standard free energy of formation for DyNi sub 5 determined is -125.6 kJmultmol exp -1 at 973K. The diffusion coefficient of Dy into DyNi sub 5 phase determined is 8x10 exp -10 cm exp 2 mults exp -1 at 1032K. The diffusion energy of Dy atoms in the intermetallic compound is 101.3 kJmultmol exp -1 at 973K.