▎ 摘　　要

Ellipsoidal Fe3O4 @ C nanoparticles decorated fluffy structured graphene nanocomposites were synthesized. The effect of the magnetic nanoparticle content on the microwave absorption properties was studied. As electromagnetic wave absorber, we researched the electromagnetic absorption properties of the composites that were composed of the prepared nanocomposites and paraffin with a filler loading of 80 wt% paraffin. The results showed that the nanocomposites with suitable magnetic nanoparticle showed a maximum reflection loss of - 55.02 dB at 14.8 GHz with a coating thickness of 1.5 mm; and the bandwidth less than - 10 dB reached 5.44 GHz. The microwave absorption mechanism of the ellipsoidal Fe3O4 @ C nanoparticles decorated fluffy structured graphene nanocomposites mainly came from the effect of the fluffy structure, multiple reflections, interfacial polarization, magnetic loss and dielectric loss.