Improved transport critical currents in Ag and Pb co-doped BaxK1-xFe2As2 superconducting tapes

TL;DR

This study demonstrates that co-doping BaxK1-xFe2As2 superconducting tapes with Ag and Pb significantly enhances their transport critical current density across various magnetic fields, using a novel fabrication and annealing process.

Contribution

The paper introduces a co-doping strategy with Ag and Pb to improve the transport critical current density of BaxK1-xFe2As2 tapes, combined with a specific annealing technique.

Findings

Critical current density reached 1.4x10^4 A/cm^2 at 4.2K in self field.

Co-doping enhances Jc across all magnetic fields.

Pb doping benefits low-field performance, Ag doping benefits high-field performance.

Abstract

Fe-clad BaxK1-xFe2As2 superconducting tapes were fabricated by the ex situ powder-in-tube method combined with a short high-temperature annealing technique. The effect of annealing time and different dopants on the transport properties of the BaxK1-xFe2As2 tapes were systematically studied. By co-doping with Ag and Pb, the transport critical current density Jc of BaxK1-xFe2As2 tapes was significantly improved in whole field region and the highest transport Jc was up to 1.4x10^4 A/cm^2 (Ic=100 A) at 4.2K in self field. It is proposed that the superior Jc in the co-doped samples are due to the combine effect of Pb doping at low fields and Ag doping at high fields.