Interface polarization and conduction loss in hollow CoFe2O4@PANI composites: a pathway to enhanced electromagnetic wave absorption

Interface polarization and conduction loss constitutes a crucial loss mechanism in electromagnetic wave absorption (EWA) materials, the dissipation capacity could be enhanced by regulating the electrical conductivity and heterogeneous interfaces of EWA composites. In this work, the hollow CoFe 2 O 4 microspheres are fabricated using the hydrothermal method and are subsequently compounded with polyaniline (PANI) through mechanical mixing to synthesize hollow CoFe 2 O 4 @PANI (H-CFP) composites. By adjusting the PANI content and thereby altering the interfaces of CoFe 2 O 4 and PANI, the impact on the microstructures and EWA performance is systematically analyzed for the H-CFP composites. All results indicate that the CoFe 2 O 4 microspheres are well-dispersed on PANI and greatly affect the EWA performance of the H-CFP composites. The optimized H-CFP-4 displays the outstanding EWA capacity with a minimum reflection loss (RL min ) of − 43.60 dB and an effective absorption bandwidth (EAB) of 1.71 GHz at 5.5 mm. Additionally, the superior performance of the H-CFP composites in the domain of radar stealth is further verified through CST simulation. The excellent EWA behavior is attributed to the interface polarization, conduction loss and impedance matching due to the synergistic effect of conductive PANI and magnetic CoFe 2 O 4 microspheres. This study offers a novel concept for designing high-performance EWA materials suitable for complex electromagnetic environments and possesses broad application prospects.