Fabrication and transport properties of Sr0.6K0.4Fe2As2 multifilamentary superconducting wires

TL;DR

This study demonstrates that flat rolling enhances the density and critical current density of Sr0.6K0.4Fe2As2 superconducting wires, showing promising potential for practical applications of iron-based superconductors.

Contribution

It systematically investigates the effect of cold-work deformation, especially flat rolling, on the superconducting properties of multifilamentary Sr-122 wires, highlighting process-structure-property relationships.

Findings

Flat rolling significantly increases the superconducting core density.

The best wire achieved a critical current density of 21.1 kA/cm^2 at 4.2 K.

The critical current density shows weak magnetic field dependence at high fields.

Abstract

Seven-core Ag/Fe sheathed Sr0.6K0.4Fe2As2 (Sr-122) superconducting wires were produced by the ex situ powder-in-tube (PIT) method. The relationship between the cold-work deformation process and the superconducting properties of wires were systematically studied. It was found that flat rolling can efficiently increase the density of the superconducting core and largely improve the transport critical current density (Jc) of as-drawn wires. The Jc of the best sample achieved 21.1 kA/cm^2 at 4.2 K in self field, and showed very weak magnetic field dependence in high fields. Our result suggested a promising future of multifilamentary iron-based superconductors in practical application.