Optimizing the electromagnetic wave absorption performances of designed Fe3O4@SiO2@MnO2 hybrids

Whereas growing numbers of strong-absorption materials have been synthesized in recent years, it is also necessary to design broad-bandwidth, low-thickness, high-intensity absorbers. The ternary Fe 3 O 4 @SiO 2 @MnO 2 hybrids were fabricated via hydrothermal and hydrolysis processes, combined with typical core-shell structure characteristics and heterogeneous properties, further generating interfacial polarization behavior and enhancing anisotropy. Investigations of micromorphology manifested the hierarchical characteristic via the presence of inner mesoporous Fe 3 O 4 cores, outer SiO 2 layers (approximately 10 nm) and MnO 2 nanosheets as the surface of the hybrids. On the basis of rational design, the optimized multi-layers absorber exhibited excellent absorption performance with optimal reflection loss (RL min ) of −50.2 dB at 13.9 GHz, and the effective absorption band (EAB) is up to 5.1 GHz from 11.5 GHz to 16.6 GHz with the thickness of 2.6 mm. Due to the large surfaces, high porosity as well as the synergistic effect derived from the magnetic Fe 3 O 4 cores and dielectric SiO 2 @MnO 2 layers, this effective strategy may be endowed with high potential to design high-efficient absorbers.