Enhanced microwave absorption in C@Co/carbonyl iron fiber composite with multi-level interfaces

With the accelerated advancement of electronic information and military technology, there is a pressing need to develop high-performance absorbing materials. In this paper, we proposed to enhance the microwave absorption performance according to the coupling effect of electric-magnetic loss in magnetic composites with multi-level interfaces. Specifically, the magnetic cobalt nanoparticles were embedded within the porous carbon matrix derived from a metal-organic framework and composited with carbonyl iron fiber to prepare C@Co/CIF composites with multi-level interfaces. When the C@Co/CIF loading ratio was 30 wt%, the minimum reflection loss (RLmin) of the absorber was - 45.65 dB, and the effective absorption bandwidth was about 4.8 GHz with a matching thickness of 1.35 mm, which presented a good microwave absorption performance. Electromagnetic waves can penetrate through multiple scattering and internal reflections and eventually disappear through multi-level interfaces of C@Co/CIF composites. Meanwhile, the dielectric porous carbon, the magnetic cobalt, and CIF made a synergistic effect on the electric-magnetic loss, which was responsible for the attenuation of the electromagnetic wave. The findings of this study offer insight that can inform the design and fabrication of metal-organic framework derivatives for electromagnetic wave absorption materials.