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 degrees C in Ar-H-2 atmosphere. (C) 2011 Elsevier B.V. All rights reserved.