Synthesis and characterisation of magnetic multilayered nanowires by template directed electrodeposition

Abstract

Magnetic multilayered nanowires, such as NiFe/Cu and Co/Cu, exhibit perpendicular giant magnetoresistance, which has potential applications in sensors and high density data storage devices. This work focuses on the synthesis of magnetic multilayered nanowires using three-electrode cells and the potentiostatic pulse technique. Porous alumina templates with well defined pore size were used to synthesise arrays of oriented nanowires with controlled shape and size. Cyclic voltammetry experiments were first performed to optimise the deposition potentials for individual layers, and the compositions of the electrolytes were optimised to yield uniformity in composition and characteristics of the nanowires. Nanowires of good layering quality and uniformity have been successfully obtained using appropriate deposition conditions and electrolyte compositions. Characterisation of the nanowires was carried out using SEM, TEM and X-ray diffraction, and their magnetic properties were studied using a vibrating sample magnetometer.