Strongly Enhanced Current-Carrying Performance in MgB2 Tape Conductors by Novel C60 Doping

TL;DR

This paper demonstrates that doping MgB2 tapes with C60 significantly enhances their current-carrying capacity at high magnetic fields, surpassing traditional superconductors like NbTi and using a scalable, simple process.

Contribution

It introduces a novel C60 doping method for MgB2 tapes that achieves unprecedented high-field current densities with a scalable approach.

Findings

10-15 times improvement in in-field Jc

Jc > 4x10^4 A/cm^2 at 10 T and 4.2 K

Hirr about 10 T at 20 K

Abstract

MgB2 is a promising superconductor for important large-scale applications for both high field magnets and cryocooler-cooled magnet operated at temperatures around 20 K. In this work, by utilizing C60 as a viable alternative dopant, we demonstrate a simple and industrially scaleable rout that yields a 10-15-fold improvement in the in-high-field current densities of MgB2 tape conductors. For example, a Jc value higher than 4x10^4 A/cm^2 (4.2 K, 10 T), which exceeds that for NbTi superconductor, can be realized on the C60 doped MgB2 tapes. It is worth noting that this value is even higher than that fabricated using strict high energy ball milling technique under Ar atmosphere. At 20 K, Hirr was about 10 T for C60 doped MgB2 tapes. A large amount of nanometer-sized precipitates and grain boundaries were found in MgB2 matrix. The special physical and chemical characteristic of C60, in addition to its C containing intrinsic essence, is a key point in enhancing the superconducting performance of MgB2 tapes.