Peculiarities of Electrical Conductivity of Metal/Carbon Nanotubes Array

Abstract

A study of the electrical conductivity of mechanical mixture of both the carbon nanotubes (CNTs) (with work function of 4.7 eV) and the Cu and Al metal microparticles (with lower work functions of 4.2 and 4.0 eV, respectively) under compression is provided. As shown, the electrical conductivity of the Al and Cu powders is essentially increased with addition of the CNTs (up to 30 wt.%). The electrical conductivity dependence on the density of a powder mixture of Al with CNTs is characterized by a deep minimum observed at the concentration of 9.6 wt.% CNTs. This feature is a result of the electrons' localization in the Al 2 O 3 film formed on a sample surface. A number of factors, in particular, a shift of the Fermi level of the CNTs deep into the valence band, explain the sharp decrease in the electrical conductivity of the Al CNTs composite, unlike the Cu-based composite.

The Effect of Hydrogen Content on Electrophysical Properties of Hydrogenated Titanium – Thermally Expanded Graphite Composites

“…This effect demonstrates the transfer of charge carriers from metal particles to TEG. [2,8,[17][18][19] In addition, a decrease in the metal component of the electron concentration (due to charge ow on the TEG) should be accompanied by a certain shift of the Fermi level in the energy spectrum of the electrons. Based on calculations of the density of electronic states (DOS) of titanium and its hydrides, [20] in the Ti and TiH x systems (x ≈ 2), the Fermi level falls on sharp and narrow peaks on the DOS, so even a small decrease in electron concentration n should lead to a noticeable decrease in the value of the density of the electronic states at the Fermi level, and hence the electrical conductivity of the metal component and the composite as a whole (we assume here that the DOS itself does not change signi cantly with small changes in n).…”