Low-temperature magnetoresistance of functionalized multiwall carbon nanotubes

Abstract

Temperature and magnetic field dependencies of resistance for functionalized multiwall carbon nanotubes (MWCNTs) have been studied. The measurements were carried out in the temperature range T = 4.2–200 K. It is shown that in magnetic fields up to B = 9 T, the conductivity behavior for the functionalized MWCNTs sample can be described in terms of charge carriers weak localization and interaction phenomena. We show that the contribution to the functionalized MWCNTs conductivity due to the weak localization effect exceeds the quantum correction due to the effect of the charge carriers interaction for all the temperatures and in the entire range of the applied magnetic fields except for the magnetic fields above B = 6.5 T at T = 5 K. Within the terms of the specified models, we estimate the value of the Fermi energy and determine the explicit form of the temperature dependence of the phase relaxation time for the wave function. We show that for the functionalized MWCNTs sample, the phase relaxation time for the wave function has a less pronounced temperature dependence, and its Fermi energy is more shifted to the valence band compared to non-functionalized MWCNTs. The charge carriers’ interaction constant at different temperatures can also be estimated from our experiments.