Synergistic multi-heterointerface of nitrogen-doped reduced graphene oxide/Ce-doped SrFe₁₂O₁₉@N-doped carbon for broadband electromagnetic wave absorption

Developing lightweight microwave-absorbing materials with a low filler loading, strong attenuation capability, and broad effective absorption bandwidth is an important requirement in electromagnetic protection and radar stealth. In this work, a nitrogen-doped reduced graphene oxide/Ce-doped strontium ferrite@nitrogen-doped carbon (NRGO/Ce-SrM@NC) heterointerfacial absorbing structure was constructed by hydrothermal assembly and dopamine-derived carbonization. In this system, Ce-SrM provides the magnetic response, NRGO builds a lightweight conductive network, and the NC shell acts as an interfacial bridging layer to regulate the coupling between magnetic particles and graphene sheets. Structural characterization shows abundant defect sites and close particle-sheet contact interfaces. At a filler loading of only 5 wt%, the NRGO/Ce-SrM@NC composite achieves a minimum reflection loss (RL min ) of −53.2 dB at a matching thickness of 2.6 mm and a maximum effective absorption bandwidth (EAB) of 7.22 GHz. Its excellent electromagnetic wave absorption (EWA) performance mainly originates from the synergistic effect of balanced impedance matching, conductive loss, dipole polarization, interfacial polarization, magnetic resonance, and multiple scattering. Further CST simulations show that a PEC plate coated with the NRGO/Ce-SrM@NC composite can achieve a radar cross section reduction of 41.35 dB cm⁻¹ . Meanwhile, the simulated moth-eye-inspired gradient structure based on the NRGO/Ce-SrM@NC composite extends the EAB to cover the entire 2–18 GHz range. This study provides a feasible strategy for the design of low-filler, broadband electromagnetic wave-absorbing materials and radar stealth structures.