Electrochemical behavior of dysprosium(Ⅲ) in eutectic LiF-DyF3 at tungsten and copper electrodes

作者：Chunfa Liao^*; Boqing Cai; Xu Wang; Shumei Chen; Gong Chen; Jueyuan Lin

来源：Journal of Rare Earths, 2020, 38(04): 427-435.

Electrochemical behavior of dysprosium(Dy) ions in LiF-DyF3(24 mol%) was investigated by cyclic voltammetry,chronoamperometry and chronopotentiometry.Dy-Cu alloy samples were prepared by constant-potential electrolysis in LiF-DyF3(24 mol%) at the Cu electrode.The Cu5 Dy and Cu phases were characterized by an X-ray diffractometer and a scanning electron microscope equipped with an energy dispersive spectrometer.The results show that the reduction of Dy(Ⅲ) ions in a LiF-DyF3(24 mol%)molten salt system is found to be a quasi-reversible diffusion-controlled process which occurs via a onestep reaction involving the transfer of three electrons.The electro-crystallization processes of the Dy metal at the W electrode and the mode of nucleation confirm that progressive nucleation is dominant at high concentrations of Dy ions in the LiF-DyF3 salt.At lower concentrations,the instantaneous nucleation of Dy with three-dimensional growth of the nuclei is dominant.