Low Frequency Noise and Resistivity Characteristics of Hybrid Composites with Onion-Like Carbon and Multi-Walled Carbon Nanotubes

Abstract

The comprehensive study of resistivity and low frequency (10[Formula: see text]Hz–20[Formula: see text]kHz) noise characteristics of hybrid polymer composites with multi-walled carbon nanotubes (MWCNTs) and onion-like carbon (OLC) particles in one material have been carried out in the wide temperature range ((75–380) K). The characteristic dependences on the fillers density and the dominant conduction mechanisms were investigated. At low temperature ((75–170) K), the resistivity dependences on temperature are well-fitted by the Mott’s formula for the quasi-one-dimensional charge carrier variable range hopping and Arrhenius law. At temperatures above 300[Formula: see text]K, the resistance increases with temperature due to matrix expansion and decreases due to the onset of the conductivity in the matrix. Low frequency voltage noise spectra comprise of 1/[Formula: see text] and Lorentzian-type components with characteristic times in the range from 0.1[Formula: see text][Formula: see text]s to 10[Formula: see text][Formula: see text]s; the noise spectral density in the region of Ohmic resistance is proportional to the voltage square. Therefore, thermally activated charge carrier capture centers randomly modulate the sample’s resistance and control the carrier hopping. Impulse noise and more sudden changes of the noise characteristics were observed at the temperatures, where the conduction mechanisms change.