Low-Frequency Noise and Resistivity of Hybrid MWCNT/Ni@C/EPOXY Composites

Low-frequency noise (10[Formula: see text]Hz–20[Formula: see text]kHz) and electrical resistivity characteristics of hybrid composites with multi-walled carbon nanotubes (MWCNT) and carbon-coated nickel (Ni@C) were investigated to identify the characteristics of charge carrier transport. Electrical fluctuations in the investigated composite materials are comprised mainly of 1/f type components. In hybrid MWCNT/Ni@C composites, the optimal concentration of Ni@C, where composite resistivity is lowest, is found to be 0.2[Formula: see text]vol.% Ni@C. The resistivity of single-filler Ni@C composites generally increases with temperature. The resistivity dependence on temperature of composites containing MWCNT varies depending on the Ni@C concentration, with suboptimal concentrations of Ni@C resulting in increased resistivity and thermal instability. In composites containing MWCNT and 0 or 0.2 vol.% of Ni@C, Arrhenius’ thermal activation is observed as the dominant charge carrier transfer mechanism in the temperature range of 75–184[Formula: see text]K, with activation energies of approximately 37.7 and 36.13[Formula: see text]meV, respectively.