Enhanced structural ordering and coercivity in FePt nanowire arrays by addition of Zn

Arrays of FePt and (FePt)84Zn16 nanowire with diameter around 40 nm and 1.5 μm in length have been synthesized from an aqueous electrolyte by codepositing Fe, Pt and Fe, Pt, Zn into porous anodic alumina. The morphology, structure, and magnetic properties of the nanowire arrays are characterized by FE-SEM, TEM, XRD and SQUID. We find that the addition of Zn to FePt nanowires is an effective approach for reducing the ordering temperature of FePt. The (FePt)84Zn16 nanowires start ordering after annealing at 350 °C, which is lowered by 150 °C with respect to FePt nanowire arrays. The coercivity of the (FePt)84Zn16 nanowires is around 2 kOe after annealing at 350 °C for 30 min. The effect of Zn-doping on decreasing the annealing temperature required to produce L10 phase FePt is studied.