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

Abstract

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 Fe3O4@SiO2@MnO2 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 Fe3O4 cores, outer SiO2 layers (approximately 10 nm) and MnO2 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 (RLmin) 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 Fe3O4 cores and dielectric SiO2@MnO2 layers, this effective strategy may be endowed with high potential to design high-efficient absorbers.