Salvato, M.Lucci, M.Ottaviani, I.Cirillo, M.Tamburri, E.Orlanducci, S.Terranova, M.L.Notarianni, M.Young, C.C.Behabtu, N.Pasquali, M.2013-03-272013-03-272012Salvato, M., Lucci, M., Ottaviani, I., et al.. "Transport mechanism in granular Ni deposited on carbon nanotubes fibers." <i>Physical Review B,</i> 86, (2012) American Physical Society: 115117. http://dx.doi.org/10.1103/PhysRevB.86.115117.https://hdl.handle.net/1911/70849We investigate the transport properties of granular nickel electrodeposited on carbon nanotube fibers by measuring the electrical resistance and the current voltage characteristics as a function of the temperature. The bare fiber is governed by a three-dimensional variable range hopping transport mechanism, however, a semiconducting to metallic transition is observed after the Ni deposition as a consequence of the evolution from weak to strong coupling between the deposited nickel grains. The experimental results indicate that the charge transport in the Ni-coated fiber develops from hopping governed by the Coulomb blockade in the case of small grains dimensions to a metallic electron phonon interaction mechanism for large grains dimensions. Tunneling enhanced by thermal fluctuation is responsible for the transport in the intermediate conductivity range. The role of the fiber and the effects due to the magnetic nature of the nickel grains are also discussed.engArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.Journal articlehttp://dx.doi.org/10.1103/PhysRevB.86.115117