Control over the magnetic interactions in magnetic nanoparticles (MNPs) is a crucial issue to the future development of nanometer-sized integrated “spintronic” applications. Here, we have developed a nanohybrid structure to achieve room temperature ferromagnetism, via a facile, effective, and reproducible solvothermal synthesis method. The plan has been put onto cobalt (Co) NPs, where the growth of Co NPs on the surface of reduced graphene oxide (rGO) nanosheets switches the magnetic interactions from superparamagnetic to ferromagnetic at room temperature. Switching-on ferromagnetism in this nanohybrid may be due to the hybridization between unsaturated 2p_z orbitals of graphene and 3d orbitals of Co, which promotes ferromagnetic long-range ordering. The ferromagnetic behavior of Co-rGO nanohybrid makes it excellent material in the field of spintronics, catalysis, and magnetic resonance imaging.

控制磁性纳米颗粒（MNP）中的磁性相互作用是纳米级集成“自旋电子”应用未来发展的关键问题。在这里，我们已经开发出一种纳米杂化结构，通过一种简便，有效且可重现的溶剂热合成方法来实现室温铁磁性。该计划已应用于钴（Co）NP上，在室温下，还原氧化石墨烯（rGO）纳米片表面上Co NP的生长将磁性相互作用从超顺磁性转变为铁磁性。纳米杂化中的铁磁性开启可能是由于不饱和2p _z石墨烯的轨道和Co的3d轨道，可促进铁磁远距离有序化。Co-rGO纳米杂化物的铁磁行为使其成为自旋电子学，催化和磁共振成像领域的优秀材料。