Ag nanoshell-induced dual-frequency electromagnetic wave absorption of Ni nanoparticles

摘要

The electromagnetic wave absorption properties of the epoxy resin composites containing Ni, Ag, and Ni-Ag core-shell nanoparticles were studied. Interestingly, Ni-Ag core-shell nanoparticles showed a dual-frequency absorption property in 2-18 and 18-40 GHz, although Ni nanoparticles exhibited absorption only in 18-40 GHz and no absorption was observed for Ag nanoparticles in the whole frequency range. The additional absorption of Ni-Ag core-shell nanoparticles in 2-18 GHz might be due to the lags of polarization between the core/shell interfaces, which contributed to the dielectric loss. The frequency dependences of permittivity and permeability and the absorber thickness effect were also investigated.