Fabrication of $hbox{K}_{rm x}hbox{Fe}_{2-{rm y}}(hbox{Se}_{1-{rm z}}hbox{S}_{rm z})_{2}$ Superconducting Tapes by a Chemical-Phase-Transformation PIT

摘要

We have fabricated monocore superconducting tapes of using a process based on a chemical phase transformation from 112-type (nonsuperconducting) to 122-type (superconducting) via a supply of Fe from the Fe sheath by annealing. Transformation of tape core from the 112 type to the 122 type was observed at the annealing temperature above 600 . The obtained superconducting tape showed superconductivity at 29.1 K. The magnetic of (at 4.2 K and self-field) was obtained for the sample annealed at 625 for 5 h followed by quenching.