Electrochemical behavior of Fe(II) in acetamide–urea–NaBr–KBr melt and magnetic properties of inductively codeposited Nd–Fe film

Abstract The electroreduction of Fe(II) and Nd(III) in MCl x –acetamide–urea–NaBr–KBr were studied by cyclic voltammetry and chronoamperometry. The reduction of Fe(II) to Fe is an irreversible process, the value of αn α of the electrode reaction was calculated to be 0.31 and the diffusion coefficient of Fe(II) was calculated to be 9.53 × 10 −7  cm 2  s −1 at 343 K. Nd(III) cannot be reduced alone in urea melt, but Nd–Fe can be codeposited by induced codeposition. The composition of Nd–Fe film varies with the Nd(III)/Fe(II) molar ratio, at the potential of −1.25 V the maximum content of Nd in Nd–Fe film is 60.4 wt%. The morphology of Nd–Fe film was investigated by SEM and AFM. Nd–Fe film comprises of nanoparticles with the size about 100–200 nm. X-ray diffraction (XRD) shows it is amorphous. After heat-treatment at 1173 K the crystal Nd 2 Fe 17 phase can be formed. The magnetic properties of the Nd–Fe films were determined using hysteresis loops, at 5 K the coercive field H c of Nd (62.6 wt%)–Fe amorphous film is 1225 Oe, the remanent magnetization M R and the saturation magnetization M S are 5.15 and 15.80 emu g −1 , respectively.