Structural and magnetic properties of electrochemically assembled Ni-Pb/Al2O3 nanostructures

Ni-Pb/Al2O3 nanostructures having composition of Ni 84 at.%, Pb 16 at.% were successfully fabricated by AC electrochemically assembled within the nanopores of ordered porous alumina films prepared by a two-step anodization. SEM images revealed that the pore arrays are regularly arranged throughout the alumina film and parallel each other. TEM analyses showed that the Ni-Pb nanoarrays are polycrystalline with dimension uniformity around 20 nm in diameter and lengths up to several μm. X-Ray diffraction results revealed that the Ni-Pb nanoarrays do not form metastable alloy phase. Hysteresis loops determined by VSM indicated that the Ni-Pb/Al2O3 nanostructures obtained possess obvious magnetic anisotropy, and the perpendicular coercivity is lower than that of Ni nanowires before and after annealing.