Electrochemical Synthesis of Magnetostrictive Fe-Ga/Cu Multilayered Nanowire Arrays with Tailored Magnetic Response

Arrays of nanowires are fabricated with alternating segments of the magnetostrictive alloy Fe1–xGax and Cu using electrochemical deposition in nanoporous anodic aluminium oxide (AAO) templates. The difficult nature of Ga‐alloy electrochemistry is overcome by controlling mass‐transfer and hydrodynamic conditions using novel rotating disk electrode templates to obtain highly uniform segment lengths throughout the arrays. Extensive structural characterization by XRD, EBSD and TEM reveals a strong textured Fe1–xGax growth. Furthermore, using vibrating sample magnetometry (VSM), we demonstrate that control of magnetization reversal processes is possible once uniform aspect ratios are obtained for both the Fe–Ga and Cu segments. Magnetostrictive Fe–Ga/Cu multilayered nanowires are synthesized using citrate‐based electrochemistry, resulting in strong textured growth. Coercivity versus applied field angle data reveal that, at high angles, the magnetization reversal mechanisms are different in continuous (curve A) to those of multilayered structures (curves B–E). This is attributed to mixed mode reversal involving vortex and coherent rotation modes in continuous wires.