NixPb1-x nanowire arrays: effects of annealing.

Ni(x)Pb(1-x) nanowire arrays were successfully fabricated by AC electrodeposition within the nanopores of ordered porous alumina films prepared by a two-step anodization. Transmission electron microscopy analyses showed that the Ni-Pb nanoarrays are polycrystalline with dimension uniformity around 20 nm in diameter and lengths up to several micrometers. X-ray diffraction results revealed that the face-centered-cubic (fcc) Ni and fcc Pb peaks are detected when the Ni component (x) is below 0.71, indicating that the Ni(x)Pb(1-x) nanoarrays do not form metastable phase alloy. Hysteresis loops determined by vibrating sample magnetometer indicated that the Ni(x)Pb(1-x) nanoarrays obtained possess obvious magnetic anisotropy, and the perpendicular coercivity was lower than that of pure Ni nanowries before and after annealing. Annealing under magnetic field was carried out to examine the effect of a magnetic field on magnetic properties using an electromagnet field up to 0.3 T.