Magnetic properties of electrodeposited nickel-MWCNT nanocomposite films

Carbon nanotubes (CNTs) alone and in form of composite materials [1] have been a core subject of nanotechnology due to their extraordinary mechanical properties, significant electron transport, magnetic and optical properties for potential applications in spintronics, electronics, energy storage and a wide range of other devices. Metal matrix-CNT nanocomposites are exciting materials for several applications. A considerable amount of attention has been devoted to nickel-CNT nanocomposites due to their functionality in fuel cells, rechargeable batteries, hydrogen storage, magnetic recording heads, and MEMS. Magnetic properties of Ni-CNT materials have been studied for Ni encapsulated CNTs by electrodeposition in form of highly ordered Ni-filled CNTs for drug delivery biomedical applications [2], for nanoelectronic devices, high-density magnetic memories [3,4]. On the other hand, Ni-CNT nanocomposite films produced by electrodeposition have been mainly investigated for their mechanical and anti-corrosion applications and there is little information of the magnetism of Ni-CNT composite films. This would be very useful for such durable and stiff candidate materials for magnetic memory and spintronic device applications. On the electrodeposition of metal with commercially available CNT into composite films, it is essential to mention that the CNTs tend to entangle and form bundles in solution due to their high surface energy, and does not disperse properly in the electrodeposition baths. In order to tackle this problem, many methods have been employed and developed that can be categorized into two general routes: (a) covalent functionalization, and (b) non-covalent functionalization.