Structural Dependence of Magnetic Properties in Co-Based Nanowires: Experiments and Micromagnetic Simulations

The magnetic properties of several series of cylindrical Co and CoFe nanowires with tailored hexagonal or cubic crystalline symmetry are reviewed. Nanowires are prepared by electroplating filling the self-assembled nanopores of anodic alumina membranes. Their structure is tailored through the electroplating conditions to present cubic (fcc Co and bcc CoFe) or hcp hexagonal ([101], [110] and [002] textures) symmetry. Hysteresis parameters (i.e., coercivity and remanence) are measured in parallel and perpendicular to nanowires magnetic field configurations. Micromagnetic simulations have been performed taking into account the different crystalline anisotropy of nanowires. They show that the magnetization reversal process takes place in hcp symmetry crystal phase wires by vortex-like domain wall and quasi-curling mechanisms, while for fcc and bcc symmetries crystal phases only a vortex domain wall is involved resulting in high-squareness hysteresis loops.