Abstract
The effects of the additives of 0.005-0.3mol of CaCO3(CaO), SrO, CaF2 and SrF2 to 2mol of the "2223" phase on the sintering behavior and the superconducting properties were investigated. The "2223" phase had a composition of Bi1.8Pb0.4Sr2.0Ca2.0Cu3.2Oy. The typical sintering temperature was 850°C for the CaO- or SrO- added system and was a little lower -840°C, for the CaF2- or SrF2- added system, when the sintering was conducted for 120hr using specimens press-formed at 5000 kg/cm2. The bulk density of the 0.3mol CaO-added specimen sintered at 850°C was 4.8g/cm3, and the critical current density, Jc at 77K, was -103A/cm2, better than that of the SrO-added specimen. The fluoride-added specimens had higher densities 5.3-5.5g/cm3, while the Jc was not increased. Tc was not influenced by the additives and remained at -110K.
