Construction of MZBF@PPy composite nanofibers with heterogeneous core-shell structure for enhanced microwave absorption

The design of low-dimensional structures and the construction of heterogeneous interfaces are promising approaches for developing efficient microwave absorption materials (MAM), whose properties have the potential to improve the microwave absorption capacity of single-phase materials. Barium ferrite is an excellent MAM due to its excellent high-frequency magnetic properties and structural stability. However, its poor conductivity and weak polarization limit its applications. In this study, Mn-Zr doped M-type barium ferrite nanofibers were synthesized by electrospinning and high-temperature pyrolysis. A conductive polymer layer of polypyrrole was then polymerized in situ on the fiber surface to form a composite nanofibrous MAM with a one-dimensional core-shell heterostructure. At the microscopic level, a conductive polymer heterostructure interface was constructed on the surface of the one-dimensional ferrite fibers. The magnetoelectric coupling network at the interface induced interfacial polarization and increased the conduction loss, which improved the microwave absorption performance. The results show that the optimized sample, benefiting from multiple loss mechanisms and excellent impedance matching, achieved a minimum reflection loss of −44.20 dB at 8.7 GHz with a matching thickness of 4.0 mm. It also exhibited an effective absorption bandwidth of 3.5 GHz. Therefore, this study demonstrates that the synthesis and application of low-dimensional organic/inorganic magnetoelectric composites as heterogeneous microwave absorbers have broad prospects.