Electron spin resonance in electrodeposited cobalt nanowire arrays

Abstract

Arrays of magnetic nanowires electrodeposited into nano-channel templates have attracted a lot of attention and research efforts in recent years. They are a promising system for perpendicular magnetic recording media. A major issue regarding the fabrication of such nanowires is the interplay between the structure and magnetic properties. In this paper template-assisted electrodeposition technique using a three-electrode electrochemical cell is used to produce high density cobalt nanomaterial arrays with cylindrical shapes. The morphology of the samples is investigated by means of Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The length and average diameter of Cobalt nanowire arrays was found 4-15 μm and ~300 μm, respectively. The structural characteristic of the samples is examined using XRD and EDX, which confirm the hexagonal closely packed cobalt array structures. Magnetic property measurements show the influence of morphology on the magnetic properties of the arrays. Magnetic characterizations were carried out by Magneto-optical Kerr Effect (MOKE) and Electron paramagnetic resonance (EPR). The experimental results suggest close agreement with the resonance field seen in micro-magnetic modelling. We have calculated the resonance field for single nanowires with different length and for an array of seven nanowires. It is shown that the resonance field varies with the length, the interaction strength and also the spacing of the nanowires. © 2012 VBRI Press.