▎ 摘　　要

The effect of graphene doping on the microstructure and superconducting properties of MgB2 bulks was examined in comparison with the case of un-doped MgB2. The correlation among annealing temperatures, microstructures and superconducting properties in graphene doped MgB2 bulks was investigated. The phase, microstructure and superconductivity of MgB2 were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and superconducting quantum interference device (SQUID), respectively. The results show that the graphene doping results in an obvious improvement of the critical current density. The highest critical current density reaches 1.8x10(5) A/cm(2) at 20 K and 1 T.