We report electrical conductivity measurements of polymethyl-methacrylate filled by onion-like carbon particles with a primary particle size of ≈5 nm. We show that the conductivity σ is exceptionally high even at very low loadings and that its low-temperature dependence follows a Coulomb gap regime at atmospheric pressure and an activated behavior at a pressure of 2 GPa. We interpret this finding in terms of the enhancement under the applied pressure of the effective dielectric permittivity within the aggregates of onion-like carbons, which improves the screening of the Coulomb interaction and reduces the optimal hopping distance of the electrons.
Electrical transport in onion-like carbon—PMMA nanocomposites
Claudio Grimaldi, Egon Kecsenovity, Maryam Majidian, Vladimir L. Kuznetsov, Arnaud Magrez, László Forró; Electrical transport in onion-like carbon—PMMA nanocomposites. Appl. Phys. Lett. 11 March 2019; 114 (10): 103102. https://doi.org/10.1063/1.5085936
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