A facile approach to prepare Ni, Co, and Fe nanoarrays inside a native porous alumina template via a redox reaction

We report a novel approach to prepare magnetic metal (e.g.Ni, Co and Fe) nanowire arrays by reduction of metal chloride salts in the pores of an anodic aluminum oxide (AAO) template with a backside Al sheet via a hydrothermal process. When a magnetic field was applied during the redox reaction, the Ni nanoarrays exhibit an enhanced magnetic anisotropy behavior. It is shown that the coercivity field and squareness are distinct for different directions, especially the coercivity of the AF// (300 Oe) is much larger than the AF⊥ (20 Oe).