Electrical conductivity of silicon carbonitride-reduced graphene oxide composites

Silicon carbonitride ceramics-reduced graphene oxide (SiCN-rGO) composites are synthesized using polyvinylsilazne (PVSZ) and GO as precursors and N-dimethylformamide (DMF) as a solvent. We find that the electrical conductivity of SiCN-rGO composites exhibits nonmonotonic changes as a function of GO concentrations, in which the conductivity increases by six orders of magnitude from 7.41E-09 (Omega/cm)(-1) to 4.35E-03 (Omega/cm)(-1) after the integration of 0.2 wt% GO, followed by three orders of magnitude drop to 3.34E-06 (Omega/cm)(-1) when 0.3 wt% GO is integrated. Based on the energy-dispersive spectroscopy and Raman spectroscopy analysis, we conclude that the conductive behavior of SiCN-rGO composites is controlled by both the concentration and the distribution of free-carbon in the composites.