Structure and magnetic properties of the Co x Pt100-x nanowire arrays

Co–Pt alloy nanowires with different components have been successfully fabricated by alternating current (AC) electro-deposition into the nanopores of the anodic aluminum oxide (AAO) template. SEM and TEM images reveal that the nanowires are uniform and parallel to each other. The aspect ratio of nanowires is over 100. XRD and EDS patterns indicate that Co–Pt nanowires are nanocrystalline at room temperature. For the as-prepared samples, the magnetocrystal anisotropy is very small, therefore, Co content and shape anisotropy play a dominant role in contributing to the improvement of coercivity and squareness. Meanwhile, the Co–Pt alloy nanowires transforms from a hard magnetic phase of fcc CoPt to a relatively soft magnetic phase of fcc CoPt3 when the annealing temperature is above 400 °C. The structure and magnetic properties of nanowires after annealing are studied and discussed in this paper.