Aqueous Electrodeposition and Mechanism of Iron Group-Vanadium Ternary Alloys

Abstract

Composition of ternary CoFeV deposits can be varied and tailored by control of the [Fe]/[Fe + Co] solution molar ratios and solution pH. Near 2V Permendur compositions were obtained with Bs of 2.35T and Bs of 2.39T for DC and PC deposits, respectively. Annealing deposits in vacuum at 820oC for 2 hours increased Br to equivalent 2V Permunder. X-ray diffraction patterns show microstructures of mixed HCP, FCC and BCC planes, depending on deposit composition. Co-rich deposits had HCP preferred orientation but as Fe content increases HCP plane disappeared and Fe BCC plane became the preferred orientation. Surface morphology changed from a needle-like structure in Co-rich deposits to nodular appearance with increasing Fe content. A hydrogen atom mechanism for the reduction of the oxovanadium, Co(II) and Fe(II) within the heterodinuclear and heterotrinuclear biscitrate complexes is proposed. This mechanism is also applicable to aqueous electrodeposition of IG-Mo and IG-W alloys.