Fabrication of high-loading Fe3O4-decorated concave SiC composite fibers for electromagnetic wave absorption

Microwave absorption materials play a vital role in electromagnetic compatibility applications, where electromagnetic coupling between dielectric and magnetic components is crucial. However, in most reported systems, the magnetic loss capability is generally weaker than dielectric loss. To address this issue and achieve ultra-high loading of magnetic particles, concave SiC fibers were designed and fabricated via electrospinning, providing abundant active sites and enhanced surface curvature for effective deposition of magnetic components.Fe 3 O 4 nanoparticles were in situ grown on SiC fibers via a hydrothermal method to prepare lightweight Fe 3 O 4 /SiC composite fiber microwave absorbers. Systematic investigations reveal that an appropriate Fe 3 O 4 loading uniformly covers the fiber surface, forming abundant heterointerfaces and enhancing dielectric and magnetic loss.Query A high Fe 3 O 4 loading of up to 90 wt% was successfully achieved in the composite system.The Fe 3 O 4 -1:2 sample achieves a minimum reflection loss (RLmin) of−40.62 dB at 6.95 GHz with a 4.0 mm thickness, effectively absorbing over 99.99% of incident electromagnetic waves and exhibiting a wide absorption bandwidth. These results indicate that the synergistic dielectric–magnetic loss and multi-interface polarization mechanisms significantly improve electromagnetic wave absorption, providing a promising strategy for designing lightweight, high-performance ceramic-based absorbers.