Mesoscopically ordered Fe3O4/C nano-composite for superior broadband electromagnetic wave absorption

• The orderly Fe 3 O 4 with carbon layer at the mesoscopic scale were designed. • F/C-O exhibits the broadband (6.40 GHz) and strong absorption (-50.47 dB). • The good impedance matching and magnetic loss contribute excellent performance. • The loss mechanism is explained through simulation and calculation. Due to the seriousness of the electromagnetic pollution, it is urgent to develop high-efficiency broadband electromagnetic wave absorption (EMA) materials. As a traditional EMA material, the question of expanding absorption bandwidth for Fe 3 O 4 /C composite need to be addressed. Based on this consideration, rationally designed Fe 3 O 4 /C nano-composite with the regular mesoscopic (1–100 nm) arrangement structure has practical significance. Benefited from this unique structure, the obtained Fe 3 O 4 /C mesoscopic ordered nano-composite exhibits broadband absorbing characteristics in 2–12 GHz. The effective absorption bandwidth value of the material is 6.40 GHz at low frequency (covered C band) and the minimum reflection loss is −50.47 dB. The superior broadband is derived from the good whole-test-frequency impedance matching and the strong low-frequency magnetic loss, which is achieved by the regularly mesoscopic arrangement of the magnetic nanoparticles. This study will provide certain inspirations and guidance for the design of low frequency broadband EMA materials in the future.