Anisotropic Magnetism and Magnetoresistance in Iron Nanowire Arrays

Abstract

Highly ordered ferromagnetic iron nanowire (Fe NW) arrays with diameters of about 60 nm and 200 nm were fabricated by electro-chemical deposition into anodic aluminum oxide (AAO) templates. The magnetization measurements show the 60 nm NWs as having a larger anisotropic magnetization. This result was illustrated by the magnetic easy axis and preferred crystal orientation of [110] along with the longitudinal direction of the NWs, revealed by the X-ray diffraction (XRD) patterns. The obtained quadratic magnetic field dependence of the normalized magnetoresistance (MR) at low field for both 60 and 200 nm NWs is attributed to the anisotropic magnetoresistance in low-dimensional systems. Furthermore, the enhanced AIR, observed in the 60 nm NWs is attributed to additional spin-diffusion mechanisms.