Open Access Nano Express

Synthesis of High Coercivity Core–Shell Nanorods Based on Nickel and Cobalt and Their Magnetic Properties

TN Narayanan1, MM Shaijumon2, PM Ajayan2 and MR Anantharaman1*

Author Affiliations

1 Department of Physics, Cochin University of Science & Technology, Cochin, 22, Kerala, India

2 Department of Mechanical Engineering & Materials Science, Rice University, Houston, TX, USA

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Nanoscale Research Letters 2009, 5:164-168  doi:10.1007/s11671-009-9459-7

Published: 21 October 2009

Abstract

Hybrid magnetic nanostructures with high coercivity have immense application potential in various fields. Nickel (Ni) electrodeposited inside Cobalt (Co) nanotubes (a new system named Ni @ Co nanorods) were fabricated using a two-step potentiostatic electrodeposition method. Ni @ Co nanorods were crystalline, and they have an average diameter of 150 nm and length of ~15 μm. The X-ray diffraction studies revealed the existence of two separate phases corresponding to Ni and Co. Ni @ Co nanorods exhibited a very high longitudinal coercivity. The general mobility-assisted growth mechanism proposed for the growth of one-dimensional nanostructures inside nano porous alumina during potentiostatic electrodeposition is found to be valid in this case too.

Keywords:
Magnetic nanowires; Nanorods; Hybrid nanostructures; Core–shell nanostructures; Mobility-assisted growth mechanism