The investigation of perpendicular anisotropy of ternary-alloy magnetic nanowire arrays using first-order-reversal-curve (FORC) diagrams

FeCoZn nanowires with controlled diameters have been prepared using pulse electrochemical deposition in anodized aluminum oxide templates. The magnetic measurements revealed significant effect of annealing on the saturation magnetization (Ms) and coercivity of nanowires. When the applied field was along the wire axis, the coercivity of as-deposited nanowires was found to be almost independent of diameter, while that of the annealed nanowires decreased with diameter. FORC diagrams of annealed sample with 80 nm diameter showed crossover of magnetic easy axis from parallel to perpendicular to the wires axis. The as-deposited nanowire arrays show uniform diameter along the whole lengths of nanowires. The X-ray diffraction analysis revealed the segregation of magnetic and nonmagnetic phases, i.e. two peaks corresponding to (1 1 0) FeCo and (1 0 1) Zn.