Array of nickel nanowires enveloped in polyaniline nanotubules and its magnetic behavior

Abstract

An array of nickel nanowires enveloped in polyaniline nanotubules was prepared by the “second-order-template” method. As the first step, an array of the polyaniline nanotubules was synthesized in the pores of an alumina membrane, then nickel nanowires were fabricated by electrochemical deposition of the nickel into the polyaniline nanotubules. The composite nanostructure was characterized by x-ray powder diffraction, and scanning electron micrography. Its magnetic properties were measured by a vibrating sample magnetometer. The coercivity and remanence are of high anisotropy with a maximum at θ=90° (parallel to the nanowires).

Ferromagnetic resonance on Ni nanowire arrays

“…21 The squareness (M R /M S ) is equal to 0.273 in the perpendicular configuration and is increased up to 0.715 in the parallel configuration. These values are slightly higher than the values reported by Cao et al, 22 reflecting weaker interaction among nanowires. Within the ideal nanowire approach (i.e., assuming a cylinder-like symmetry and neglected all contributions excepting the Zeeman and shape anisotropy), no hysteresis loop is expected to be recorded when the external magnetic field is perpendicular to nanowires.…”

On the growth mechanism of nickel and cobalt nanowires and comparison of their magnetic properties

“…The high relative intensities of the 220 and 111 diffraction lines in the case of Ni NWs is evidence for strong texturing along the 110 direction [28]. FESEM images (Figs.…”

Controllable Synthesis and Magnetic Properties of Cubic and Hexagonal Phase Nickel Nanocrystals

“…[17] Furthermore, Salem et al assembled Ni nanowires and Au nanowires into a sandwiched heterogeneous structure of Au/Ni/Au through a bio-programmed procedure. [18] In the past few years, our research group has also done a lot of work on the controllable synthesis of magnetic Ni nanostructures, such as highly ordered Ni nanotube arrays, [19] sub-micrometer-sized hollow Ni spheres and their composites, [20,21] nanometer-sized hollow Ni spheres, [22] nanocable structures filled with Ni nanowires, [23,24] as well as tubein-tube nanostructures composed of Ni nanotubes and carbon nanotubes, [25] and studied their magnetic properties. However, to the best of our knowledge, the Ni nanostructures reported are all in the cubic phase and controllable synthesis of Ni nanostructures with a different crystal phase has not been reported until now.…”