Fabrication of FeSe0.5Te0.5 Superconducting Wires by an Ex Situ Powder-in-Tube Method

We report the fabrication of Cu/Nb-sheathed FeSe0.5Te0.5 superconducting wires by an ex situ powder-in-tube method. After swaging and drawing, the as-drawn wires were heat-treated at different heat conditions. Subsequently, characterizations and transport critical current measurements were performed on the heat-treated FeSe0.5Te0.5 wires. Also, the results of the as-drawn wire are presented for comparison. The FeSe0.5Te0.5 cores reacted with the Nb sheaths when heat-treated at a high temperature or at a low temperature for a long time. Furthermore, according to our results, the highest transport critical current density (Jc) at 0.5 and 0.75 T is about 1.6 × 10 4 and 1.5 × 10 3 A/cm 2, respectively.