Preparation and millimeter wave attenuation properties of NiFe2O4/expanded graphite composites by low-temperature combustion synthesis

• NiFe2O4/EG composites are prepared by low-temperature combustion synthesis.
• NiFe2O4/EG composites are uniform and have a good crystallinity.
• The MMW attenuation performance was studied upon MMV radar measurement device.
• NiFe2O4/EG composites exhibit better MMW attenuation properties than EG.
• We report a simple synthesis route for the preparation of MMW attenuation composites.

In this paper, NiFe2O4/expanded graphite (EG) composites are successfully prepared by low-temperature combustion synthesis method. The morphology, structure and millimeter wave (MMW) attenuation properties of the NiFe2O4/EG composites are investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectra, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and MMV radar measurement device. The effects of fuel and stoichiometric ratio on the composites are also investigated. The results show that NiFe2O4/EG composites are uniform and have a good crystallinity. The composites possess better MMW attenuation properties than EG. The 3 and 8 MMW attenuation performances of NiFe2O4/EG composites are 8.5 dB and 14.6 dB, respectively.