Temperature dependence of the resistivity and structure of carbon nanotube films containing various kinds of tubules
Omel'yanovskii O. E. , Tsebro V. I. , Lebedev O. I. , Kiselev A.N., Bondarenko V. I. , Kiselev N. A. , Kosakovskaja Z. Ja., Chernozatonskii L. A.
The temperature dependence of the resistivity is measured over a range of 4.2 to 300 ë on carbon films containing multilayer nanotubes (MLTs) or single-layer nanotubes (SLTs) oriented perpendicular to the substrate. The structure of these films is examined by high-resolution electron microscopy. At low temperatures, the planar resistivity of all the films is well fit by the expression In p°c [T0IT\lin, with Ì = 4 and TQ~ ΙΟ6 ë for the MLT films but with η = 2 and Γ0~20 ë for the films containing bundles of SLTs 0.71 nm in diameter. The data obtained are considered in terms of the variable-range hopping conductivity. The estimations made show a fairly high density of states at the Fermi level (~1021 eV_1cnT3) for the films containing SLTs. © 1995 American Institute of Physics.