Preparation of ZnO/Fe₃O₄/graphene composite and enhanced microwave absorption performance in L-band

ZnO/Fe₃O₄/graphene composite with good microwave absorbing performance in L-band was prepared via co-hydrothermal synthesis and precipitation method. The crystal structure, Raman spectra, morphology, electromagnetic parameters and microwave absorption performance of as-synthesized composite were characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscope and vector network analyzer, respectively. Compared with the pure Fe₃O₄ NPs and Fe₃O₄/graphene composite, the as-prepared ZnO/Fe₃O₄/graphene composite exhibits enhanced microwave absorption performance. The maximum reflection loss is −20.85 dB at 0.94 GHz with a −10 dB bandwidth over the frequency range of 0.65 ~ 1.29 GHz (0.64 GHz) at a match thickness of 5 mm. Moreover, the microwave absorbing properties i.e. the position, intensity, and absorption bandwidth of composite can be adjusted by controlling the thickness of absorber as well. Thus, such composite can be applied as an effective microwave absorber in L-band.