Improved Superconducting Properties in Graphene-Doped MgB2 Prepared by Coating Method

摘要

The effects of graphene doping on the phase formation and superconductivity of MgB2 bulks synthesized with different process have been studied systemically. Considering the scattering structure of graphene, coating method was applied to enhance the uniformity of graphene doping. The graphene coated B addition was expected to improve the critical current density of MgB2 bulks. In our study, several experiments were performed to find out the suitable way for graphene doping. The coating method could enhance the critical current density of MgB2 from 1.9 x 10(5) to 2.5 x 10(5) A/cm(2) at 20 K and 0 T, compared with that of the undoped sample. And the superconductivity of MgB2 prepared by coating method got obvious improvement at high field compared with that of pure graphene doping bulk. It can be concluded that the coating method could ensure the uniformity of graphene doping in MgB2 and refined the grain crystalline effectively.