| 摘要 |
PURPOSE:To obtain the superconducting wire rod with its critical current density improved at the time of producing a Tl-based oxide superconducting wire rod by limiting the proportion of a high Tc phase in the raw powder. CONSTITUTION:A step for heat-treating the raw powder is provided when the wire rod is covered with a metallic sheath. A thallium-based oxide superconductor having the composition of Tl-Bi-Ca-Sr-Cu-O or Tl-Bi-Pb-Ca-Sr-Cu-O is covered with a metallic sheath to produce the thallium-based oxide superconducting wire rod. In this case, the proportion of the 1223 phase of the 1223 composition of (Tl,Bi)-Ca-Sr-Cu or (Tl,Bi,Pb)-Ca-Sr-Cu exhibiting a relatively high critical temp. in the raw material is controlled to 40-90%. The metallic sheath is made of gold, a gold alloy, silver or a silver alloy. The heat treatment is preferably carried out at 750-900 deg.C. |
