Method of preparing oxide superconducting wire

A method of preparing an oxide superconducting wire, consisting essentially of the following sequence of steps:

• covering a powder material for forming an oxide superconductor with a metal covering, wherein said powder material consists of a superconducting phase and non-superconducting phases, and the majority of said superconducting phase consists of a 2212 phase;
• performing deformation processing on said metal-covered powder material to obtain a tape-shaped wire superconductor, wherein said oxide superconductor is a Bi-Sr-Ca-Cu (Bi,Pb)-Sr-Ca-Cu superconductor having a 2223 composition;
• superposing a plurality of said tape-shaped wire materials;
• performing a first heat treatment on said plurality of superposed tape-shaped wire materials, wherein said metal coverings are diffusion-bonded to each other during said first heat treatment step;
• performing deformation processing consisting essentially of rolling said plurality of superposed tape-shaped wire materials;
• and
• performing a second heat treatment on said plurality of deformation-processed tape-shaped wire materials.