Radar attenuation performance of magnetic expanded graphite aerosol obtained from thermal expansion of stage-1 ferrocene graphite intercalation compounds

Abstract

Expanded graphite (EG) is a carbon material prepared by the thermal expansion of graphite intercalation compounds. Herein, a novel chemical preparation method is employed to obtain magnetic EG composites with excellent radar attenuation performance in the 2–18 GHz range. Ferrocene is first intercalated into the natural flake graphite to form ferrocene graphite intercalation compounds (FGICs), and then oxidises to Fe3O4 during the thermal expansion of FGICs at 900 °C, while the FGICs are converted into magnetic EG composites in this process. The success of ferrocene intercalation reaction is confirmed by transmission electron microscopy, fourier transformation infrared spectroscope, X-ray diffraction, and energy-dispersive X-ray spectroscopy studies. The components and radar attenuation property of the magnetic EG composites are discussed. Both Fe3O4 and Fe2O3 exist in the final EG composites and a high radar attenuation of −18 dB at 18 GHz is obtained, while the ferrocene/graphite ratio in the FGICs is 20%. The excellent radar attenuation property of the magnetic EG composites, together with good homogeneity and dispersion in air, can allow the composites to be used in many potential applications in radar countermeasure. Keywords: Magnetic expanded graphite aerosol, Ferrocene graphite intercalation compounds, Radar attenuation performance, Attenuation loss measurement