Effective Ex-Situ Fabrication of F-Doped SmFeAsO Wire for High Transport Critical Current Density

TL;DR

This paper presents a method for fabricating high-performance SmFeAsO superconducting wires with enhanced critical current density using an ex-situ powder-in-tube process and a fluorine-rich binder to maintain superconducting properties.

Contribution

The study introduces a novel ex-situ fabrication technique with a fluorine-rich binder that compensates F loss, resulting in improved critical current density in SmFeAsO wires.

Findings

Achieved a transport critical current density of ~4 kA/cm2 at 4.2 K.

Successfully maintained superconducting transition temperature despite F loss.

Demonstrated the effectiveness of the binder in preserving superconducting properties.

Abstract

We demonstrate the fabrication of superconducting SmFeAsO1-xFx (Sm-1111) wires by using the ex-situ powder-in-tube technique. Sm-1111 powder and a binder composed of SmF3, samarium arsenide, and iron arsenide were used to synthesize the superconducting core. Although the F content of Sm-1111 is reduced in the process of ex-situ fabrication, the binder compensates by sufficiently supplementing the F content, thereby preventing a decrease in the superconducting transition temperature and a shrinkage of the superconducting volume fraction. Thus, in the superconducting Sm-1111 wire with the binder, the transport critical current density reaches the highest value of ~4 kA/cm2 at 4.2 K.