Influence of electrical contacts on the 1/f noise in individual multi-walled carbon nanotubes

Low-frequency noise of individual MWNTs was investigated with different metal electrodes. Irrespective of the ohmic or non-ohmic voltage-current characteristics, a strong dependence of the noise on the metal contacts was observed. The good electrical contacts with Pd or Pt electrodes enable a quasi-ballistic transport with a bigger exponent in the relation of S1 alpha R4.8, similar to 2D metallic film or graphene. On the other hand, the noise in the case of Cr or Ti electrodes is almost linear with the resistance of the nanotubes, which may be an index of the influence of the contacts in the CNTs.