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A new anchoring method by –SO3H groups was proposed to prepare γ-Fe2O3@SiO2@polypyrrole (γ-Fe2O3@SiO2@PPy) nanospheres with core/shell/shell structure. In the reaction process involved, the sulfonic-functionalized γ-Fe2O3@SiO2 (γ-Fe2O3@SiO2–SO3H) acts as the core for the polymerization of pyrrole. And PPy can be anchored to form on the surface of γ-Fe2O3@SiO2 to form γ-Fe2O3@SiO2@PPy nanospheres with the help of the sulfonic groups on the surface of γ-Fe2O3@SiO2. Moreover, flexible controllability of the conductivity and saturation magnetization of the resulting γ-Fe2O3@SiO2@PPy nanospheres can be realized through this method. The resulting electromagnetic γ-Fe2O3@SiO2@PPy nanospheres show a maximum conductivity of 53 S cm−1 and saturation magnetization of 8.17 A m2 kg−1. The method reported here may provide an efficient way to realize the best impedance matching between complex permeability and complex permittivity.

Most applications of graphene need a suitable support substrate to present its excellent properties. But transferring graphene onto insulators or growing graphene on foreign substrates could cause properties diminishing. This paper reports the graphene growth directly out of diamond (111) by B doping, guided by first-principles calculations. The spontaneous graphene formation occurred due to the reconstruction of the diamond surface when the B doping density and profile are adequate. The resulting materials are defect free with high phase purity/carrier mobility, controllable layer number, and good uniformity, which can be potentially used directly for device fabrication, e.g., high-performance devices requiring good thermal conductivity.