Method for manufacturing superconductive wire material of bismuth based oxide

摘要

A manufacturing method wherein a metal sheath is filled with a powder having a composition such that the amounts of Sr, Ca and Cu are larger than conventional so that in addition to the 2223-phase of (Bi, Pb)-Sr-Ca-Cu the phase of Sr-Ca-Cu-O may be precipitated, and then, this metal sheath is subjected to a plastic working, a primary heat treatment, another plastic working, and a secondary heat treatment in this order. A pinning point based on the phase of Sr-Ca-Cu-O is introduced into the superconductor of the obtained bismuth based oxide superconductive wire material, and thereby, the magnetic field characteristic of the critical current density is improved.