High-density nickel nanowire arrays for data storage applications

Abstract

This paper is dedicated to a study of magnetic properties (magnetic anisotropy, coercive force and remanent magnetization) of spatially ordered high-density Ni nanowire arrays. The magnetic nanowires were prepared by electrodeposition of nickel from simple sulfate solutions into anodic aluminum oxide (AAO) nanoporous templates (with diameter of d=20 and 40 nm) fabricated by potentiostatic anodization. We show that Ni nanowires have strong out-of-plane axial magnetic anisotropy (normal to the substrate plane) along with an in-plane anisotropy caused by hexagonal spatial distribution of nanowires in an array. An existence of the six-fold in-plane anisotropy proofs the long-range hexagonal order of nanowires. High quality of nanowire arrays makes possible of its usage as high-density (up to 2Tb/in2) magnetic recording media.