TITLE:
Elaboration and Magnetic Properties of Cobalt-Palladium Magnetic Nanowires Encapsulated in Carbon Nanotubes
AUTHORS:
Olivier Rousseau, Cynthia Locard, Aïchata Kane, Yves Roussigné, Samir Farhat, Salim Mourad Chérif
KEYWORDS:
Magnetic Nanowire, Filled Carbon Nanotubes, Cobalt, PECVD, Static Magnetic Measurements
JOURNAL NAME:
Journal of Surface Engineered Materials and Advanced Technology,
Vol.7 No.1,
December
22,
2016
ABSTRACT: Bimetallic one-dimensional (1-D) cobalt-palladium magnetic nanowires encapsuled by carbon nanotubes were synthesized on silicon substrate using plasma enhanced chemical vapor deposition technique. After the deposition of the catalyst, the growth of nanotubes takes place in two stages. The first is a thermal pretreatment to transform continuous nanometer bimetallic thick film into isolated and uniformly distributed nanoparticles over the entire surface of the substrate. The second step results in the growth of nanotubes perpendicular to the substrate by the addition of carbon atoms on the insulated metal nanoparticles. While growing the nanotubes at given thermochemical conditions, a Co-Pd eutectic is thought to diffuse inside the cavity of the nanotube along a length of few hundreds of nanometers as determined by high resolution, spatially resolved Electron Energy Loss Spectroscopy (EELS), and energy filtered elemental mapping. The magnetic anisotropy along the nanotube directions is observed. Ferromagnetic or superparamagnetic-like behavior of the filled nanotubes was measured through local magneto-optical Kerr effect or global superconducting quantum interference device measurements, respectively. Information on the magnetism of filled nanotubes at different scales is pointed out and discussed.