Ni@SiC composites from Ni-modified PCS-derived (SiC)_p with high-efficiency microwave absorption properties

Silicon carbide (SiC) presents significant application prospects in the light of wave-absorbing, attributed to its excellent electrical and physicochemical properties. By utilizing the synergistic loss mechanism, SiC compounding with the magnetic can markedly enhance the absorption efficiency of electromagnetic wave (EMW) which is an important technical mean to optimize the wave-absorbing capabilities. In this paper, polycarbosilane (PCS) was used as a precursor to prepare (SiC)_p and Ni@SiC composites were successfully synthesized by chemical plating without palladium activation, in order to explore the lightweight SiC-based wave-absorbing material that exhibits intense absorption and wide bandwidth. It is shown that when the (SiC)_p is about 60 μm, the A2-Ni@SiC demonstrates the minimum reflection loss (RL_min) of −50.27 dB at 8.04 GHz with an effective absorption bandwidth (EAB) of 5.64 GHz at 3.0 mm (from 7.24 to 12.88 GHz). When the particle size of (SiC)_p is further refined to about 5 μm, the prepared B2-Ni@SiC shows exceptional wave-absorbing performance achieving the RL_min of −66.10 dB at 3.4 mm, along with an EAB of 4.44 GHz (from 5.56 to 10.0 GHz). The enhancement in wave-absorbing is likely due to the increased interfacial polarization at the Ni-(SiC)_p interface, as well as the improved matching of the hybridized constituents.