Synthesis and characterisation of γ-Fe₂O₃nanowire arrays via a versatile, simple and low-cost method

γ-Fe2O3 nanowire arrays embedded in anodic alumina template were fabricated by an improved sol–gel method. The morphologies, structures and magnetic behaviour of the as-prepared products were investigated by X-ray powder diffraction, transmission electron microscopy, selected area electron diffraction, field emission scanning electron microscopy and magnetic hysteresis analysis. The results show that arrayed γ-Fe2O3 polycrystalline nanowires with an average diameter about 40 nm and an average length about 0.5 µm were prepared. A number of superparamagnetic nanoneedles grew along the nanowires. The ordered one-dimensional arrays weaken the superparamagnetic effect. In addition, a possible formation mechanism about nanowires is proposed. The charge factor, gravity effect and molecular heat movement impelled the Fe sols filling into the pores of the template. γ-Fe2O3 nanowire arrays look forward to the applications of magnetic recording in the future.