A cheap liquid additive from acetone for strong in-field Jc enhancement in MgB2 conductors

TL;DR

This study demonstrates a cost-effective method using acetone as a liquid additive to significantly enhance flux pinning and critical current density in MgB2 superconducting tapes through simple doping and grain refinement.

Contribution

It introduces a novel, inexpensive in situ doping technique with acetone that improves MgB2 superconductors' performance at lower sintering temperatures.

Findings

Achieved high Jc of 2.4x10^4 A/cm^2 at 10 T and 4.2 K with 5 wt % acetone doping.

Acetone doping causes carbon substitution and grain refinement, enhancing flux pinning.

Doping at lower sintering temperature outperforms nano-C doping at higher temperature.

Abstract

We report on significant flux pinning enhancement in MgB2/Fe tapes that has been easily obtained by a simple and cheap route using acetone as both an efficient ball-milling medium and liquid additive through the in situ method. Results showed that the highly reactive C released from the decomposition of the acetone substituted into B sites, accompanied by the grain refinement effect due to the acetone doping. At 4.2 K, the transport Jc for the 5 wt % acetone doped tapes sintered at 700C reached up to 2.4x10^4 A/cm^2 at 10 T, which is even higher than that of the nano-C added samples heated at 900C.