Electrospinning of hierarchical carbon fibers with multi-dimensional magnetic configurations toward prominent microwave absorption

Hierarchical microstructures and synergistic dielectric-magnetic effect are expected to satisfy the improvement of microwave absorption, but still face considerable challenges. Herein, we employ the electrospinning strategy and thermal reduction engineering to fabricate hierarchical carbon fibers with multi-dimensional magnetic configurations, in which Ni spheres are embedded in carbon fibers and Co sheets are anchored on the surface of carbon fibers. The results indicate that abundant hetero-interfaces combined with electromagnetic synergy promote impedance characteristics and strengthen interfacial polarization, magnetic domains with multi-dimensional configurations contribute to magnetic loss by means of intrinsic ferromagnetic resonance and magnetic coupling, and unique hierarchical architectures result in multiple scatterings. As a result, the minimum reflection loss (R_L,min) achieves a high value of −45.9 dB at 4 mm and the effective absorption bandwidth (EAB) reaches 5.9 GHz at a thickness of 2.8 mm. It is believed that this design concept opens up a novel strategy in fabricating multi-dimensional magnetic configurations and the absorbers with high-efficient absorption performance exhibit promising the potential in managing electromagnetic radiation.