▎ 摘　　要

We present an one-step procedure for the synthesis of hybrid Fe3O4 nanoparticles/graphene composite with self-assemble superlattices of Fe3O4 nanoparticles. We find that the Fe3O4/graphene nanocomposite exhibits both enhanced dielectric losses and magnetic losses at 2-18GHz, resulting from the interfacial polarizations between the Fe3O4 nanoparticles and the graphene, as well as the coupling between the neighbouring Fe3O4 nanoparticles. Theoretical simulations uncover the origins of the electromagnetic losses of hybrid Fe3O4/graphene nanocomposite and provide additional insight into the microscopic dielectric polarization mechanism. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4758931]