▎ 摘　　要

NOVELTY - Preparation of microwave absorbing material involves pouring deionized water to multi-layer graphene oxide powder, ultrasonically processing for 30 minutes to disperse graphene oxide in deionized water, adding nano-cobalt ferrite and nano-silicon carbide particles to the multi-layer graphene oxide aqueous solution, adding ethylene glycol, stirring for 2 hours, transferring the solution to reaction kettle, placing in oven at 200℃ for 12 hours to obtain reduced graphene oxide/silicon carbide/cobalt ferrite sample material, adding deionized water and ethanol to the sample after the reaction, centrifuging 3 times at 8000 rpm for 4 minutes each time, vacuum drying at 60℃ for 24 hours, taking out for grinding, mixing the ground product and paraffin in mass of 3:2, and adding to mold, pressing it into coaxial ring with outer diameter of 7 mm, inner diameter of 3 mm, and ring thickness of 3 mm, and testing its electromagnetic parameters using a vector grid analyzer. USE - Preparation of microwave absorbing material. ADVANTAGE - The preparation method is simple, quick and efficient, and produces high-performance microwave absorbing material without strictly controlling the reaction temperature and time, and is suitable for large-scale production, and solves problems that the existing microwave absorbing material is thin, light, wide and strong, which is difficult for one material to meet requirement of microwave absorption at different thicknesses. DETAILED DESCRIPTION - Preparation of microwave absorbing material involves pouring 165 ml deionized water to 0.5 g multi-layer graphene oxide (GO) powder, ultrasonically processing for 30 minutes to disperse graphene oxide in deionized water, adding 1-1.75 g nano-cobalt ferrite (CoFe2O4) and 0.25 g nano-silicon carbide particles to the multi-layer graphene oxide aqueous solution, then adding 200 ml ethylene glycol, stirring using a stirrer for 2 hours, transferring the solution to 100 ml reaction kettle, placing in oven at 200℃ for 12 hours to obtain reduced graphene oxide/silicon carbide/cobalt ferrite (rGO/SiC/CoFe2O4) sample material, adding deionized water and ethanol to the sample after the reaction, centrifuging 3 times at 8000 rpm for 4 minutes each time, vacuum drying at 60℃ for 24 hours, taking out for grinding, mixing the ground product and paraffin in mass of 3:2, and adding to mold, pressing it into coaxial ring with outer diameter of 7 mm, inner diameter of 3 mm, and ring thickness of 3 mm, testing its electromagnetic parameters in the range of 2-18 GHz using a vector grid analyzer of model N5234A and calculating theoretical reflection consumption value using the formulae: Zin= √μr/ εrtanh(j(2πfd/c))√μr.εr (1) and RL(dB) = 20lg(Zin-1/Zin+1) (2) to obtain minimum reflection consumption value (RL(dB)) of sample. Where μr = μ-'-jμ" is complex permeability, μ-' is real part of permeability, μ'' is the imaginary part of permeability, εr=ε'-jε" is complex permittivity, ε' is real part of permittivity, and ε" is the imaginary part of the dielectric parameter.