Tailoring the Magnetic Properties of Ordered 50-Nm-Diameter Coni Nanowire Arrays

CoxNi1-x alloy nanowires with varying Co content (0 ? x ? 1), having a diameter of 50 nm and a length of 3 ?m, have been fabricated by electrodeposition using an anodized aluminum oxide template. The composition and crystalline structure of the CoNi nanowires were determined by high-resolution scanning electron microscopy and energy-dispersive spectroscopy techniques. The room temperature magnetic behavior of the CoNi nanowire arrays is also studied and correlated with their structural and morphological properties. Analytical calculations of the angular dependence of the coercivity allow us to confirm that the magnetization reversal is mostly ascribed to the propagation of a transverse domain wall. Furthermore, our results indicate that the values of the effective anisotropy not only depend on the diameter of the nanowires, but also on the composition of the alloy. Finally, accurate control of the crystalline anisotropy plays a key role in the design of nanostructures with a required magnetic behavior, suitable for applications. © Springer Science+Business Media 2013.