| 摘要 |
PURPOSE:To provide a Bi-based superconducting material having excellent Jc characteristics and to provide its production method. CONSTITUTION:(1) This Bi-based superconducting material is expressed by composition formula Bi2+xSr2+yCa1-zCu2O8+a (wherein, x, y, z satisfy -0.10<=x<=0.40, 0.13<=y<=0.50, and 0.06<=z<=0.35). (2) A source material powder having the molar ratio of metal elements Bi:Sr:Ca:Cu=(2+x):(2+y):(1-z):2 is heated at temp. higher than the melting point of Bi 2212 phase in an atmosphere at >=0.002atm oxygen partial pressure, and then cooled. In the molar ratio, x, y and z satisfy the conditions described in (1). In the case of producing a silver sheath wire material, the oxygen partial pressure for heat treatment is specified to the range between >=0.002 and <=0.500. |
