SiC@Co-CNT composites with tunable electromagnetic parameters for microwave absorption

Silicon carbide (SiC) is considered as a potential wave-absorbing material, but pure SiC has a low dielectric constant and no magnetic loss. In this paper, (cobalt loaded carbon nanotubes) Co-CNT is chosen as the composite material. The conductivity of CNT is utilized to improve the dielectric properties of SiC, while the magnetic permeability of Co can enrich the loss mechanism of SiC. SiC composite cobalt loaded carbon nanotubes (SiC@Co-CNT) composites were successfully prepared by using the carbothermal reduction method. The electromagnetic parameters of the composites are regulated by adjusting the Co content, which in turn optimises the microwave absorbing performance of the composites. The results show that the microwave absorbing performance of the SiC@Co-CNT composite is significantly improved. In particular, when the Co content is 20 wt%, the reflection loss (RL) value is −57.67 dB at 10.1 GHz and 2.63 mm, and the effective absorption bandwidth is 3.75 GHz (8.05–11.8 GHz). This work provides new research ideas for the application of SiC in the field of absorbing materials. •The transmission path of electromagnetic wave is increased.•Improved magnetic loss.•Dielectric loss is enhanced.