Electrospinning of Fe/SiC Hybrid Fibers for Highly Efficient Microwave Absorption

Fe/SiC hybrid fibers have been fabricated by electrospinning and subsequent high-temperature (1300 °C) pyrolysis in Ar atmosphere using polycarbosilane (PCS) and Fe₃O₄ precursors. It is found that the introduction of Fe has had a dramatic impact on the morphology, crystallization temperature, and microwave electromagnetic properties of the hybrid fibers. In addition, the Fe particles have acted as catalyst sites to facilitate the growth of SiCO nanowires on the surface of the hybrid fibers. As a result, the permittivity and permeability have been enhanced effectively, and the high reflection loss (RL) has been achieved at a low frequency band with a thin absorber thickness. At an optimal PCS/Fe ratio of 3:0.5, the hybrid fiber/silicone resin composite (35 wt %) with a 2.25 mm absorber thickness exhibits a minimal RL of about -46.3 dB at 6.4 GHz. The wide frequency band (4-9.6 GHz) and thin absorber thickness (1.5-3.5 mm) for effective absorption (<-20 dB) prove that the Fe/SiC hybrid fiber is a promising candidate to work as a highly efficient and lightweight absorber in the C band (4-8 GHz).