Enhanced Electromagnetic Wave Absorption in CoNi/C Materials Through Incorporation of Sugar-Derived Carbon

Sugar-derived carbon materials have special electrical and optical properties, and their hybridization with magnetic alloys can generate enhanced attenuation constants and better impedance matching due to electrical and magnetic interactions. This study prepared CoNi/C composite materials and modified the microstructure and dielectric constant of magnetic alloys by selecting carbon sources and controlling carbonization processes. The results showed that CoNi/C flakes carbonized using glucose-derived carbon at 500°C exhibited a significant reflection loss (RL) of −42.91 dB and an effective absorption bandwidth covering 6.08 GHz (RL < −10 dB). In addition, CST simulations show that CoNi/C significantly reduces the radar cross section (RCS) value by 35.28 dB m². Compared with cornstarch- and fructose-derived carbon, glucose-derived carbon exhibits better impedance matching performance and wider absorption bandwidth.