The microwave absorption properties of carbon-encapsulated nickel nanoparticles/silicone resin flexible absorbing material

Carbon-encapsulated nickel nanoparticles (Ni@C) with soft magnetic nickel nanoparticle core and dielectric carbon shell were synthesized by a modified arc-discharge method. The calculated reflection loss (RL) of Ni@C/paraffin composites and the measured RL of Ni@C/silicone coatings were studied at thicknesses of 1-3 mm and Ni@C contents of 40-60 wt%. Ni@C nanoparticles show good microwave absorption properties in 2-18 GHz. The minimum calculated RL is −39.82 dB with 60 wt% Ni@C at 3 mm, and the calculated RL <−10 dB can be obtained in the frequency of 5-13.41 GHz. Meanwhile, the minimum measured RL reaches −20.54 dB with 60 wt% Ni@C loading at 2.5 mm and the widest bandwidth of measured RL <−10 dB is 3.64 GHz with 60 wt% Ni@C loading at 1.5 mm.