The dielectric permittivity modulation effect of phase engineering on SiC whiskers modified reduced graphene oxide composites

Silicon carbide whiskers (SiCw) have garnered significant attention as advanced electromagnetic wave absorbers owing to their exceptional high-temperature stability, corrosion resistance, tunable electromagnetic properties, and distinctive heteropolytypic structural characteristics. Nevertheless, practical applications remain constrained by inherent limitations including insufficient intrinsic electromagnetic dissipation capacity and insufficient understanding of microstructure-property correlations in pure SiCw systems. To address these challenges, we develop reduced graphene oxide-based composites incorporating silicon carbide whiskers featuring semiconductor heterojunctions through crystallographic phase engineering. Structural characterization confirms that carbothermal reduction at 1400 °C induces abundant semiconductor heterointerfaces within SiCw, significantly enhancing axial polarization through intensified charge distribution asymmetry. This engineered architecture substantially elevates the complex permittivity while optimizing interfacial polarization-dominated dissipation mechanisms. The optimized RGO@SiO₂/SiC composite demonstrates exceptional electromagnetic wave absorption performance, achieving a minimum reflection loss of −71.53 dB at 2.54 mm thickness with an effective absorption bandwidth spanning 5.65 GHz. These findings establish fundamental principles for designing high-efficiency electromagnetic wave absorbers through crystallographic phase engineering in silicon carbide nanostructures.