Electrodeposition of NdFeB films in DMI-LiNO3 ionic liquid analogs at room temperature
(1. Key Laboratory for Ecological Metallurgy of Multimetallic Mineral (Ministry of Education), Northeastern University, Shenyang 110819, China;
2. School of Metallurgy, Northeastern University, Shenyang 110819, China)
2. School of Metallurgy, Northeastern University, Shenyang 110819, China)
Abstract: The feasibility and reaction mechanism of NdFeB film electrodeposition in 1,3-dimethyl-2-imidazolidinone (DMI)-LiNO3 ionic liquid analogs at room temperature were investigated. Cyclic voltammetry indicated that the reduction peak at -1.83 V (vs Ag) was related to the reduction of Fe(II) to Fe, while the reduction peak at -2.01 V (vs Ag) was related to the reduction of B(III) to B. The electrochemical reduction reaction of Fe(II) and B(III) were irreversible processes controlled by diffusion, and the diffusion coefficients of Fe(II) and B(III) at 313 K were 3.03×10-6 and 6.74×10-7 cm2/s, respectively. In addition, XRD analysis suggested that the product obtained by the electrodeposition in DMI-LiNO3-Nd(CF3SO3)3-FeCl2-H3BO3 ionic liquid analogs for 2 h on the Al substrate contained NdFe3B3. SEM and EDS analysis showed that Nd, Fe, and B in the cathode product were uniformly distributed. XPS analysis revealed that the mass fractions of Nd, Fe, and B on the W substrate were 27.44%, 27.90%, and 7.51%, respectively.
Key words: ionic liquid analogs; electrodeposition; NdFeB film; cyclic voltammetry