Electrical Transport and Magnetoresistance in Single-Wall Carbon Nanotubes Films

Abstract

Electrical transport properties and magnetoresistance of single-wall carbon nanotubes (SWCNT) films were investigated within temperature range (2-300) K and in magnetic fields up to 8 T. A crossover between metallic (dR/dT > 0) and non-metallic (dR/dT < 0) temperature dependence of the resistance as well as low-temperature saturation of the resistance in high bias regime indicated on the diminishing of role of the contact barriers between individual nanotubes essential for the charge transport in SWCNT arrays. The magnetoresistance (MR) data demonstrated influence of weak localization and electron-electron interactions on charge transport properties in SWCNT films. The low-field negative MR with positive upturn was observed at low temperatures. At T > 10 K only negative MR was observed in the whole range of available magnetic fields. The negative MR can be approximated using 1D weak localization (WL) model. The low temperature positive MR is induced by contribution from electron-electron interactions.

Low temperature charge transport in arrays of single-walled carbon nanotube bundles with radiation induced defects

“…As one can see in Fig. 2, this dependence describes well the experimental results with the characteristic field E 0 values equal to 5.8⋅10 5 , 5.2⋅10 5 , and 1.4⋅10 6 V/cm for the samples S1, S2 and S3, respectively. Using the obtained values of E 0 and T 0 , one can calculate the localization length of charge carriers:…”

“…These studies have been carried out using various types of CNT arrays (carbon nanotubes bundles, aligned fibers, networks, films, mats, etc. ), and there was found that the electrical properties strongly depend on morphology of arrays and the quality of contacts between individual nanotubes (see, for example [3][4][5][6][7]). In fact, since CNT arrays are formed by randomly distributed nanotubes, the contacts play the role of insulating barriers along the conduction path.…”