Ru doped magnetic nanoparticles embedded in mesoporous silica for effective microwave absorption by interface engineering and DFT calculations

Abstract

Strong absorption, thin thickness, wide-bandwidth as well as lightweight of microwave absorption materials (MAMs) are highly desirable. In this study, the mesoporous silica skeleton embedded by FeRu/(Fe, Ru)3O4 magnetic nanoparticles (FR/FRO-mSiO2) were designed and fabricated by vacuum impregnation and reduction sintering methods. The minimum reflection loss (RLmin) of the FR/FRO-mSiO2 composite with a metal mass ratio of 46% was −61.1 dB at a thickness of 2.0 mm, and the covered absorption bandwidth (RL < −10 dB) reached 6.8 GHz. In combination of Density functional theory (DFT) calculation, microstructure characterizations and electromagnetic characteristics, we found that the interface polarization and magnetic enhancement at the interfaces of FeRu-(Fe, Ru)3O4, the local dipole moment, and the abundant propagation channels for the incident microwaves, endowed by the unique component and construction of FR/FRO-mSiO2, contributed together to the excellent microwave absorption capability of FR/FRO-mSiO2. This work provides a promising porous structure to broaden efficient bandwidth and strengthen microwave absorption intensity with lightweight.