Substitution induced pinning in MgB_2 superconductor doped with SiC nano-particles

TL;DR

This study demonstrates that doping MgB_2 with SiC nano-particles introduces effective intra-grain pinning sites, significantly enhancing critical current density with minimal impact on transition temperature.

Contribution

It presents a novel doping method using SiC nano-particles to induce intra-grain pinning in MgB_2, improving its superconducting performance.

Findings

Enhanced magnetic field dependence of critical current density

Intra-grain pinning sites successfully introduced

Minimal decrease in transition temperature

Abstract

By doping MgB_2 superconductor with SiC nano-particles, we have successfully introduced pinning sites directly into the crystal lattice of MgB_2 grains (intra-grain pinning). It became possible due to the combination of counter-balanced Si and C co-substitution for B, leading to a large number of intra-granular dislocations and the dispersed nano-size impurities induced by the substitution. The magnetic field dependence of the critical current density was significantly improved in a wide temperature range, whereas the transition temperature in the sample MgB_2(SiC)_x having x = 0.34, the highest doping level prepared, dropped only by 2.6 K.