Electrochemical Formation of Nd-Ni Alloys in Molten LiF-CaF2-NdF3

Abstract

The electrochemical formation of Nd-Ni alloys was investigated in a molten LiF-CaF2-NdF3 (0.30 mol %) system at 1123 K. Cyclic voltammetry and open-circuit potentiometry indicated the formation of several phases of Nd-Ni alloys. Potentiostatic electrolysis was conducted to prepare an alloy sample using a Ni plate electrode at 0.15 V vs. Li+/Li for 75 min. Cross-sectional scanning electron microscopy revealed that the entire Ni plate was transformed into Nd-Ni alloy. X-ray diffraction analysis confirmed that the alloy consisted predominantly of the NdNi2 phase with NdNi3 as the minor phase. When the electrolytic potential was changed to 0.35 V and 0.60 V after electrolysis at 0.15 V for 75 min, the resultant phases were NdNi3 and NdNi5, respectively. The formation potential for each Nd-Ni alloy phase was determined from the experimental results.