Control of magnetic anisotropy of Co nanowires

Cobalt nanowires were fabricated by DC electrodeposition onto anodic aluminium oxide (AAO) templates. The effects of AAO pore diameter, current density, pH, annealing and deposition under external magnetic fields on the structure and magnetic properties of the nanowire arrays were studied. It is found that the smaller pore size produces high crystallinity, resulting in improved magnetic performance at low current density. The pH can transform fcc-Co phase to hcp-Co phase, with the easy axis along the nanowire axis switched over to the perpendicular direction. Annealing demonstrates excellent thermal stability of the magnetic nanowire arrays at high temperature. The application of external magnetic field during deposition influences the growth habit of the nanowires, leading to the change in the magnetic properties.