▎ 摘　　要

We developed a seed-assisted method to grow ultra-thin gamma-Fe2O3 nanosheets with a paramagnetic behaviour on the surfaces of graphene sheets. Scanning electron microscopy and the transmission electron microscopy measurements showed that the length, height and thickness of the nanosheets were about 140, 120 and 5 nm, respectively. The measured electromagnetic parameters indicated that the three-dimensional (3D) graphene/gamma-Fe2O3 nanosheet arrays exhibited a significantly enhanced electromagnetic wave absorption property compared to that of the graphene sheets and some magnetic nanomaterials. The minimal reflection loss was less than -15.2 dB for 3D graphene/gamma-Fe2O3 nanosheet arrays with thicknesses of 2 mm, and it was up to -64.1 dB when the thickness was 4.92 mm. Good electromagnetic wave absorption properties of the 3D graphene/gamma-Fe2O3 nanosheet arrays indicate that they are very promising for applications in the electromagnetic wave absorbing field.