Preparation of a Nickel–Holmium Alloy Coating in an Equimolar HoCl3-Containing NaCl–KCl Melt

Abstract

Cyclic voltammetry is used to study the electrolytic reduction of holmium ions on a nickel electrode in a holmium chloride-containing equimolar molten mixture of sodium and potassium chlorides in a temperature range of 1073–1173 K. The potentials of formation of nickel–holmium intermetallic compounds (IMCs) are determined. Nickel–holmium intermetallic compounds are synthesized by controlled potential electrolysis. Under the selected electrolysis conditions, the prepared coating is shown to be single-phase and its composition corresponds to the HoNi₂ stoichiometry. The coefficients of reaction diffusion of holmium in nickel are calculated and the activation energy of alloy-formation process is determined.