SiC aerogel composites modified by carbon nanotubes encapsulated with Fe nanoparticles for microwave absorption

Adjusting the electromagnetic parameters and impedance characteristics through reasonable control of microstructures and composition has become a common way to obtain high-performance electromagnetic wave absorbers. In this paper, a unique porous SiC aerogel based composite microwave absorber loaded with carbon nanotubes (CNTs) and Fe nanoparticles has been successfully constructed by chemical vapor deposition (CVD). By modulating the deposition time, the mass of CNTs and Fe can be adjusted. The combination of magnetic/dielectric materials and special porous structures can not only improve the electromagnetic loss ability through multiple magnetic/dielectric loss mechanisms, but also effectively improve the impedance matching, which significantly improves the absorber's performance of electromagnetic wave absorption and losses. The minimum reflection loss (RLmin) of -35.0 dB at 11.5 GHz and a broad effective absorption bandwidth (EAB, RL < -10 dB) of 5.6 GHz (9.4-15.0 GHz) can be realized at the deposition time of 30 minutes. Moreover, the RLmin of the absorber reaches as high as -49.6 dB at the deposition time of 60 min. This work provides an alternative for the construction of high-performance lightweight foam electromagnetic wave absorbers.