Magnetic behavior of NixFe(100−x) (65⩽x⩽100) nanowire arrays

Arrays of magnetic nanowires with composition NixFe(100−x) (65⩽x⩽100), 35 nm in diameter and 2000 nm long have been prepared by electrodeposition filling of highly ordered nanoporous alumina membranes. Long-range order of nanopores, with crystalline domain size of around 2 μm2 and 105 nm 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 1.23 kOe 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.