Electromagnetic synergistic enhancement of SiFeBOC ceramics prepared by the polymer-derived ceramic method by Fe3Si and SiO2 nanowires for tunable microwave absorption

SiOC ceramics are recognized for their exceptional chemical stability and favorable dielectric loss properties, making them viable candidates for microwave-absorbing applications. Nonetheless, the reliance on a singular loss mechanism limits their effectiveness in achieving efficient wave absorption. In this study, we introduce the SiFeBOC ceramic, which integrates Fe 3Si spheres and SiO 2 nanowires through a straightforward sol-gel method combined with a polymer-derived ceramic technique to incorporate magnetic particles into SiOC ceramics. The resulting material exhibits multiple loss mechanisms, including interfacial polarization, dipolar polarization, conduction loss, natural resonance, and eddy current loss, which collectively enhance its wave-absorbing capabilities. At a thickness of only 1.9 mm, the SiFeBOC ceramics achieve a minimum reflection loss (RL min ) of -47.96 dB and an effective absorption bandwidth (EAB) of 3.25 GHz. Additionally, a broader bandwidth of 4.39 GHz is achieved at a reduced thickness of 1.6 mm, with an RL value of -44.54 dB and an EAB of 4.05 GHz at 1.5 mm. The reflection loss per unit thickness (RL/t) reaches a minimum value of -29.69 dB/mm, while the effective absorption bandwidth per unit thickness (EAB/t) achieves a minimum of 2.74 GHz/mm. Furthermore, radar scattering cross-section (RCS) measurements reveal enhanced radar stealth capabilities compared to a perfect electrical conductor (PEC), with an RCS reduction of 7.72 dB·m 2 at 0° and an RCS min of -53.27 dB·m 2 at 146°. This study demonstrates that SiFeBOC ceramics possess significant potential for use in high-efficiency microwave absorption applications. Furthermore, it offers insights for the advancement of a new generation of microwave-absorbing materials characterized by low profile, broad bandwidth, and thin dimensions.