Construction of magnetic nanoparticle channels in SiC/SiO₂ composite foam toward efficient electromagnetic wave absorption

The combination of dielectric-magnetic loss synergy and rational microstructure construction is conducive to satisfy the thin thickness, strong absorption and wide frequency bandwidth of the absorbers. In this study, a novel strategy of constructing magnetic nickel nanoparticle channels inside SiC/SiO₂ composite foams for the synthesis of Ni/SiC/SiO₂ porous composites (NSPC). The magnetic nickel nanoparticle channels retain SiC/SiO₂ composite foam internal pore structure, which can optimize the impedance matching and satisfy the dielectric-magnetic loss synergy effect. The results confirm that the presence of multiple heterogeneous interfaces in NSPC, the magnetic and conductive losses imparted by magnetic particles and the unique foam porous structure synergistically make it have extremely excellent electromagnetic wave (EMW) absorption properties. NSPC can obtain ultra-strong reflection loss of −64.86 dB (1.46 mm) and the effective absorption range covers 13.20 GHz (4.80–18 GHz) at a total thickness of 1.79 mm (1.21–3 mm), representing 82.5 % of the whole range of frequencies. Additionally, RCS simulation confirms that NSPC can dissipate more electromagnetic capability in a real environment. In short, this work provides a new reference for the development of materials with rational microstructure construction while achieving thin thickness, strong absorption and broadband absorption.