Core-shell SiC@Fe₃O₄ with high-efficiency electromagnetic wave absorption attributed to enhanced interfacial polarization via electron irradiation modification

Electron irradiation generates substantial interfacial charges in modified silicon carbide (SiC) nanoparticles through carbon vacancy defect formation. Using a solvothermal decomposition method, we fabricated an Fe₃O₄ shell on the SiC surface, creating a core-shell structure with enhanced interfacial polarization that significantly improves electromagnetic wave absorption. The incorporated Fe₃O₄ introduces complementary magnetic loss. At an 8:1 feeding ratio, the i-SiC@Fe₃O₄ nanoparticles achieve exceptional performance with a minimum reflection loss (RL _min) of −59.57 dB at 3.72 mm thickness and an effective absorption bandwidth (EAB) of 7.4 GHz. With a 4:1 ratio, the composite attains an ultra-wide EAB of 8.0 GHz at 3.05 mm. Microstructural and electromagnetic analysis confirms dielectric loss from polarization relaxation as the dominant absorption mechanism, with secondary magnetic loss contribution. Notably, the Fe₃O₄ coating preserves the dual-frequency absorption behavior while inducing a strategically valuable shift of the effective absorption band from Ku-band to X-band, advancing practical electromagnetic wave absorption applications.