Bi-based superconducting material, Bi-based superconducting wire having the same, and method of manufacturing the superconducting wire

摘要

PURPOSE: To produce a superconducting material usable easily at more than about 40K and having a high critical current density under a environment in which a magnetic field is impressed by mixing Bi2212 phase and (Bi, Pb) 1212 phase in a specified ratio. CONSTITUTION: In a Bi based superconducting material containing simultaneously the Bi2212 phase and the (Bi, Pb) 1212 phase, when a content of the former is Xmol.% and the content of the latter is Ymol.%, 0.25=X/Y=1.5. A material of the Bi2212 phase is, for example, a material expressed by formula Bi2 Sr2 Ca1 Cu2 O8 , and the material of the (Bi, Pb) 1212 phase is, for example, the material expressed by formula (Bi0.75-x Pbx Cu0.25 )Sr2 (Y0.5 Ca0.5 )Cu2 O7 (In the formula, 0.35=x=0.75). These material are mixed in a specified ratio, and orientation is formed with crystal particles of the Bi2212 phase which is relatively large in crystal particles and plain, and high critical current density (=3000A/cm2 ) is obtained even in a magnetic field by the (Bi, Pb) 1212 phase combined with the crystal of this Bi2212 phase.