Preparation of ternary Fe₃Si/SiC/Si₃N₄ nanofiber material for wideband electromagnetic wave absorption

To achieve high-performance electromagnetic wave absorption in silicon carbide (SiC) nanofibers, it is essential to address both impedance matching and energy loss mechanisms. This study introduces a multiphase synergistic modification strategy: incorporating Si₃N₄ to improve surface impedance matching and adding magnetic Fe₃Si to enhance energy dissipation. The effects of carbothermal reduction temperatures on material composition, structure, and absorption properties were systematically investigated. At 1500 °C, the optimized composite demonstrated exceptional performance with a minimum reflection loss (RL_min) of −62.34 dB at 6.40 GHz and a broad effective absorption bandwidth of 14.02 GHz (3.98–18 GHz), covering 77.89 % of the tested frequency range. The Fe₃Si/SiC/Si₃N₄ ternary composite nanofibers form an “inductance-capacitance-resistance” microcircuit structure, which enhances polarization loss, conductivity loss and magnetic loss, thereby improving the electromagnetic wave absorption performance of SiC nanofibers.