Enhanced Microwave Absorption Performance of SWCNT/SiC Composites

The present work emphasizes the microwave absorption performance of single-walled carbon nanotube (SWCNT)/SiC composites prepared by mechanically mixing the components, i.e., SWCNT and SiC in desired weight fractions using a cost-effective and simple ball-milling route. The microwave absorption results reveal that the integration of SiC with a small weight fraction of SWCNT exhibited an improved absorption performance in the Ku band compared to pristine SiC. The SWCNT/SiC composite with 2.5 wt.% SWCNT exhibited a superior microwave absorption behavior with a minimum reflection loss of − 37.11 dB and < − 10 dB absorption bandwidth of 4.38 GHz for the absorber thickness of 2 mm. The microwave absorption efficiency of SWCNT/SiC composites was also measured corresponding to − 10 dB, which is equivalent to 90% microwave absorption when evaluating the absorption performance. A maximum microwave absorption efficiency of 18.95 dB GHz/mm was observed for the composite with 2.5 wt.% SWCNT dispersion compared to 3.4 dB GHz/mm for pristine SiC. Enhanced microwave absorption characteristics for SWCNT/SiC composites may be attributed to various absorption mechanisms, such as dipole polarization, multiple scatterings, multiple reflections, conductive loss, interfacial polarization, and defect-induced dipole polarization. The microwave absorption results of SWCNT/SiC composites indicate that they may serve as encouraging thin thickness candidates with superior microwave absorption for application in the Ku band.