Magnetic Multilayer Composites Based on Carbon Nanotubes Modified SiC/BaFe₁₂O₁₉ for Wideband Microwave Absorption

Silicon carbide (SiC) has attracted widespread attention as an absorber material due to its excellent high-temperature stability and corrosion resistance. However, issues such as low absorption strength and narrow absorption bandwidth still need to be addressed. In response to these challenges, a core–shell structure of barium ferrite nanoparticles deposited on the surface of SiC was prepared by hydrothermal method and annealing process in this study, and the microwave absorption performance of SiC was effectively improved by multicomponent nanocomposite. On this basis, genetic algorithm and electromagnetic simulation software CST design and calculate multilayer microwave absorption structures satisfying additional absorbing requirements. Among various techniques, a double-layer microwave absorption structure with a thickness of 2.8 mm was selected as the verification model and then precisely prepared according to the optimal structure. The testing results closely resembled the simulated performance, providing robust validation of the accuracy of the multilayer optimization. The optimized double-layer composite demonstrated an effective absorption bandwidth of 8.8 GHz (9.2–18 GHz) at 2.8 mm thickness. Furthermore, a finite element model was established to quantitatively examine energy dissipation and systematically investigate how impedance matching in the double-layer structure affects the microwave absorption performance. The results indicate that the SiC-based magnetic-carbon composite with a multilayer structure design has excellent potential in wideband microwave absorption applications.