Investigation of electrical transport in hydrogenated multiwalled carbon nanotubes

Highly disordered multiwalled carbon nanotubes of large outer diameter (similar to 60 nm) fabricated by means of chemical vapor deposition process inside porous alumina templates exhibit ferromagnetism when annealed in a H-2/Ar atmosphere. In the presence of an applied magnetic field, there is a transition from positive to negative magnetoresistance. The transition may be explained in terms of the Bright model for ordered and disordered carbon structures. Additionally, temperature dependent electrical transport experiments exhibit a zero-bias anomaly at low temperature. (C) 2010 Elsevier B.V. All rights reserved.