Electromagnetic synergy in Fe3O4@Polypyrrole nanorod composites derived from MIL-88A for high-performance microwave absorption

The growing demands from sectors such as advanced electronic packaging and defense have made the creation of high-performance electromagnetic wave (EMW) absorbers a research and development priority. In this study, α-Fe 2 O 3 @PPy (FOP1) and Fe 3 O 4 @PPy (FCP1) composites were synthesized via controlled thermal treatment of MIL-88A under varying conditions, followed by in-situ oxidative polymerization. This synthetic strategy allows precise tuning of the composition and microstructure of the composites, thereby facilitating systematic investigation of the synergistic electromagnetic effects on microwave absorption performance. The absorption properties of FOP1 are characterized by a minimum reflection loss (RL min ) of −21.96 dB at 6.14 mm. Furthermore, a thickness of 3.19 mm yields an effective absorption bandwidth (EAB) of 2.96 GHz. The FCP1 composite exhibits markedly superior performance, achieving an RL min of −56.03 dB at 3.64 mm and an ultra-wide EAB of 6.2 GHz at a mere 2.41 mm thickness. This performance enhancement is attributed to its enhanced magnetic loss capability and significantly improved impedance matching. A substantial radar cross-section (RCS) reduction of 33.21 dB m 2 was observed in the specular reflection direction (0°), as confirmed by simulations. This result corroborates the excellent electromagnetic wave absorption performance of the material. The remarkable microwave absorption is driven by the effective integration of multiple loss mechanisms, including interfacial polarization, conductive loss, dipole polarization, and magnetic loss. The material's performance stems from the concurrent enhancement of attenuation efficiency and impedance matching enabled by this integration. This work offers valuable insights into the design of high-performance microwave absorbers through tailored electromagnetic synergy.