The electrodeposition of NiFe nanowires-with the length ∼3.0 μm and diameter 200 nm-using the porous anodized aluminum oxide (AAO) templates on the sputtered Au-back electrode (300 nm) using sulfate/chloride electrolyte solution and potential pulsed deposition. The electrode area of Au-AAO template, determined by the reversible one-electron transfer oxidation of K₄Fe(CN)₆, used as a probe in CV, was found to be ∼2.4 times larger than Au-thin film electrode. The anomalous codeposition phenomenon known as a „volcano” type curve-with a maximum in Fe-content in NiFe as a function of the applied potential-was observed in the literature. The observed results were explained through the limited mass transport of Fe⁺² ions after the peak. This explanation is partially correct, but not complete. The electrodeposition of NiFe nanowire in this work resulted in a similar “volcano” type curve. The alternative explanation of anomalous codeposition-through the surface concentration of H⁺ dependent adsorption/desorption of FeOH⁺ and NiOH⁺ electroactive species-was proposed. The electrodeposition of NiFe nanowire arrays using a designed pulse potential method produced fcc NiFe nanowires with 5–55% Fe with controlled composition, length, and uniformity.

Among all transition metals magnetic alloys, Co₃₅Fe₆₅ possesses the highest saturation magnetization B_S = 2.45 T at room temperature given by the so-called “Slater-Pauling limit”. For controlled electrodeposition of Co₃₅Fe₆₅ nanowire arrays the following parameters were found to be optimal: electrolyte solution with 1–2 mM malonic acid (MA), ionic ratio Fe⁺²/Co⁺² = 2.0, growth rate, and pulsed potential deposition with time-on (2.5 s) at the potential of −1.15 V/SCE and time-off (1.0 s) at −0.70 V/SCE. These arrays were deposited inside anodic aluminum oxide (AAO) templates that contained columnar nanopores with diameters either 35 or 200 nm. Cyclic voltammetry was used in solution with and without MA and reaction mechanism was proposed to explain the critical role of MA in electrodeposition of CoFe alloys. In addition to uniform deposition of stechiometric Co₃₅Fe₆₅ alloys, a selectivity ratio, (SR) ∼1.0, were achieved, which means that the atomic ratio of Fe/Co in the nanowire matched the molar ratio of Fe⁺²/Co⁺² in the electrolyte. The magnetic behavior of the subsequent 2.45 T Co₃₅Fe₆₅ nanowire arrays showed that the shape and magnetostatic anisotropies dominated the effective anisotropy, and the impact of magnetocrystalline and magnetelastic anisotropies field was very small.