Preparation and microwave absorption properties of graphene/pure ferrite composite absorbers

Abstract

To develop lightweight, broadband, and high-efficiency graphene-based microwave absorbing materials, graphene/pure ferrite composite absorbers with different mass ratios (N1–W3) were prepared via a hydrothermal method. The effects of the graphene-to-ferrite mass ratio on the electromagnetic parameters and absorption performance were systematically investigated. The microstructure was characterized by XPS, SEM, TEM and XRD, the absorption mechanisms were discussed. Results show that ferrite particles (0.1–0.5 μm) are uniformly loaded on the surface of graphene sheets, forming a composite structure. Electromagnetic parameter analysis indicates that with increasing ferrite content, the imaginary part of permeability increases, enhancing magnetic loss; the synergistic effect of dielectric loss and magnetic loss effectively improves impedance matching. At an absorber thickness of 3 mm, sample W3 (graphene:pure ferrite = 1:3) exhibits a maximum reflection loss of –23.8 dB at 11.8 GHz, with an effective absorption bandwidth of 3.7 GHz, demonstrating the best absorption performance among all the prepared samples, indicating that an appropriate graphene-to-ferrite ratio is essential for balancing dielectric and magnetic losses. Microstructural analysis reveals that interfacial polarization, multiple reflections, and defect-induced polarization relaxation between graphene and ferrite are key to the excellent absorption properties. This study provides experimental evidence and design strategies for developing high-performance graphenebased composite absorbers.