Polymer-derived SiOC ceramic composites with surface-tuned ZrB 2 for broadband electromagnetic wave absorption

The demanding operational environments of advanced aerospace vehicles urgently require electromagnetic wave (EMW) absorbing materials that simultaneously possess broad bandwidth and exceptional high-temperature stability. ZrB 2 exhibits great potential as an EMW absorber due to its excellent electrical conductivity; however, its application is severely limited by surface-induced impedance mismatch. Herein, we demonstrate that the electromagnetic attenuation behavior of nano ZrB 2 is governed by its surface states, which dictate the trade-off between impedance matching and conduction loss. To exploit this mechanism, surface-tuned ZrB 2 nanoparticles were integrated into a polymer-derived SiOC ceramic matrix. Benefiting from the synergy between enhanced micro-conduction networks and optimized impedance matching enabled by surface engineering, the resulting composites exhibit superior cross-band EMW absorption. Specifically, the composite achieves a remarkable effective absorption bandwidth (EAB) of 10.8 GHz (7.2–18.0 GHz), successfully covering the entire X and Ku bands as well as a segment of the C band, at a matching thickness of 4.1 mm. These findings elucidate the role of nanostructure surface states in regulating dielectric behaviors, providing insights for designing next-generation, high-temperature EMW absorbers for advanced stealth applications.