Magnetic behavior of NixFe(100-x) (65=<x=<100) nanowire arrays

Arrays of magnetic nanowires with composition NixFe(100-x) (65=<x=<100), 35nm in diameter and 2000nm long have been prepared by electrodeposition filling of highly ordered nanoporous alumina membranes. Long-range order of nanopores, with crystalline domain size of around 2μm2 and 105nm lattice parameter of hexagonal symmetry, is achieved by self-ordering process, and characterized by SEM and AFM. Magnetic behavior of the arrays has been determined by VSM. Maximum coercivity of around 1.23kOe and reduced remanence (about 0.8 saturation magnetization) is observed for x=77, while minimum values are observed for x=100. Detailed AFM and MFM studies allow us to gain additional information of the filling degree of pores which can result in a distributed nanowires length that finally correlates with a deterioration of macroscopic magnetic behavior of the array