Facile preparation of the dendritic Fe3O4 with a core-shell microstructure in SiO2-B2O3-Al2O3-CaO-Fe2O3 glass-ceramic system for enhanced microwave absorbing performance

Highlights: • A dendrite-like Fe₃O₄ with a core-shell structure was created in a multi-component glass system. • The unique three-dimensional hierarchical structure contributes to the synergy of dielectric loss and magnetic loss. • The EM consumption mechanism is mediated by the glass phase and the three-dimensional dendritic core-shell crystals. • The preparation method is facile for the designing of high-performance microwave absorbing materials (MAMs). -- Abstract: The hierarchical architecture constitutes one of the key factors affecting the performance of microwave absorbing materials (MAMs). Herein, core-shell Fe₃O₄ with a dendritic hierarchical structure is fabricated successfully by the melting method in a SiO₂-B₂O₃-Al₂O₃-CaO-Fe₂O₃ multi-component system. The multiple transmission scattering absorption mechanism is mediated by the unique microstructure, thus improving the impedance matching and the microwave loss ability of the material. According to its reflection loss curve, the microwave absorption was efficiently optimized, yielding a minimum reflection loss (R_L) of − 54.26 dB when the thickness was 3.47 mm, and the effective bandwidth (R_L < 10 dB) for electromagnetic wave reflectance reached 3.28 GHz (6.48–9.76 GHz) with a sample thickness of 1.8 mm. The present work adds new useful information for the designing of high-performance glass-ceramic MAMs.