Synergistic Enhancement of Microwave Absorption in ZnFe2O4@PANI Composites Via Magnetic-Field-assistedin-situpolymerization.

High-performance microwave-absorbing materials require a precise balance between dielectric and magnetic losses to achieve optimal impedance matching. Herein, we report the synthesis of ZnFe2O4@PANI composites via a magnetic-field-aidedin-situoxidative polymerization method. Systematic characterization reveals that the PANI coating promotes interfacial polarization and conduction loss, while the external magnetic field during synthesis influences the dispersion and local magnetic environment of the ZnFe2O4@PANI cores. Consequently, the magnetically-assisted ZnFe2O4@PANI composite (Z3) exhibits superior electromagnetic performance, achieving a minimum reflection loss of-33.4 dB at 8.65 GHz, substantially outperforming the non-magnetic-field-assisted counterpart (Z2,-18.9 dB). The enhanced microwave absorption performance is associated with magnetic-field-regulated microstructural evolution, which contributes to improved impedance matching and a balanced magneto-dielectric response. These findings demonstrate that magnetic-field-assisted synthesis is an effective strategy for engineering advanced composites with high-efficiency, frequency-tunable microwave absorption capabilities.