TL-PB OXIDE SUPERCONDUCTING MATERIAL AND ITS PRODUCTION

摘要

PURPOSE: To obtain a Tl-Pb oxide superconducting material with the crystal structure consisting essentially of a 1223 phase and/or a 1234 phase and with the critical current density improved when energized in a magnetic field by using a precursor powder consisting essentially of a 1212 phase as the raw material. ;CONSTITUTION: A precursor powder consisting of a Tl-Pb 1212 phase shown by formula I or the 1212 phase and Ca₂PbO₄ is prepared. The precursor powder is then used as the starting material, worked and heat-treated to obtain a Tl-Pb oxide superconducting material consisting essentially of a 1223 phase shown by formula II and/or a 1234 phase shown by formula III. Consequently, the 1223 phase and/or the 1234 phase are converted to a plate crystal, the C axis orientation property is improved, the crystal grain of the 1223 phase and/or 1234 phase is increased in size, the intercrystalline joining property is improved, and the critical current density of the material is improved when energized in a magnetic field.;COPYRIGHT: (C)1993,JPO&Japio