The influence of asymmetric electrodeposition voltage on the microstructure and magnetic properties of FexCo1−x nanowire arrays

FeCo alloy nanowires were synthesized by both the symmetric and asymmetric ac electrodepositions into highly ordered porous anodic aluminum oxide membrane. The effect of deposition frequency (100, 500, 1000, 1500 and 2500 Hz), alloy composition (Fe0.1Co0.9 to Fe0.9Co0.1) and asymmetric potential (18/18, 18/16, 18/14 and 18/12 V, reductive–oxidative voltages) on the magnetic properties and microstructure of FeCo nanowires were investigated. It was found that lower frequency regions are more sensitive to the Fe and Co ion concentrations. A body-centered cubic structure with a 〈1 1 0〉 preferential orientation was observed for all nanowire arrays. The growth rate of nanowires was enhanced with an increase in the difference between reductive–oxidative voltages. The coercivity of as-deposited samples was increased from 2160 to 2850 Oe after annealing at 570 °C in Ar–H2 atmosphere.

► FexCo1−x nanowire arrays were prepared by both the symmetric and asymmetric ac electrodeposition methods in AAO templates.
► Crystalline structure of the nanowires shows a bcc structure with a 〈1 1 0〉 preferred orientation.
► Energy dispersive spectroscopy analysis reveals that the alloy composition is frequency independent and changes by Co and Fe ions concentration of the electrolyte.
► Growth rate of nanowires was enhanced with increase in reductive–oxidative voltage difference while the highest coercivity was found for the samples fabricated with symmetric potentials.
► It was found that in lower frequencies region alloy composition is more sensitive to the Fe and Co ions concentration.