Formation of Dy–Fe alloy films by molten salt electrochemical process

Abstract

The electrochemical formation of Dy–Fe alloy films was investigated in a molten LiCl–KCl–DyCl 3 (0.50 mol%) system at 773 K. The deposition potential of Dy metal was 0.47 V (vs. Li +/Li) at a Mo electrode. Repetition of the potential sweep treatment at a fresh Fe electrode was effective in increasing the rate of formation of Dy–Fe alloys. Using an Fe electrode activated by repetition of the potential sweep treatment, a DyFe 2 film was formed by potentiostatic electrolysis at 0.55 V. However, the alloy film was thin and not adhesive. An adhesive DyFe 2 film was formed at the activated Fe electrode by potentiostatic anodic electrolysis at 0.55 V after cathodically electrodepositing Dy meal at 0.40 V. By using a similar procedure, Dy 6Fe 23 was formed at 0.68 V. The equilibrium potential for (2/11)Dy 6Fe 23+Dy(III)+3e −⇄(23/11)DyFe 2 was estimated as 0.62 V.