Preparation of ternary FeSi/SiC/SiN 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 SiN to improve surface impedance matching and adding magnetic FeSi 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) 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 FeSi/SiC/SiN 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.