Improved Superconducting Properties of NaCl Doped MgB2

MgB
₂
superconducting materials have important application potential in the 20K temperature region, which is a significant advantage compared with other low-temperature superconductors (such as Nb-Ti and Nb3Sn). However, there is a big gap between its superconducting current-carrying capacity and Ni-Ti and Nb
₃
Sn, which is due to the weak magnetic flux pinning force and the poor connection between the MgB
₂
grains. Chemical doping is a simple and effective method to improve the performance of MgB
₂
. This paper studies the effect of NaCl doping on the performance of MgB
₂
. It is found that NaCl doping has a positive effect on improving the interconnection of MgB
₂
grains and refining MgB
₂
grains, and is a potentially effective method to improve the superconducting properties of MgB
₂
. In addition, all of the samples in this study showed surface pinning characteristics, but the smaller the MgB
₂
grain size, the better the match with the surface pinning characteristics described by Kramer's theory.