FABRICATION AND CRITICAL CURRENT DENSITIES OF 2223-BIPBSRCACUO SILVER SHEATHED TAPES

BiPbSrCaCuO silver sheathed tapes were prepared with the composition Bi1.8Pb0.33Sr1.93Ca1.93Cu3O9.89 and Bi1.8Pb0.4Sr2.0Ca2.2Cu3O10.3. The core thickness ranged from 70-mu(m) to 20-mu(m). The formation of the 2223 phase starts from the 2212 compound by a liquid phase reaction and is strongly influenced by to the presence of silver. j(c) parallel-to (B parallel-to tape) can be related to j(c) perpendicular-to tape) assuming that the field component B parallel-to c axis alone controls j(c)(B,T). We have deduced an average misorientation of the c-axes of the platelet shaped grains of about ten degrees. This is confirmed by SEM analysis. In case of the lead-rich compound more than 70% of the samples with 20-mu(m) in core thickness showed critical current densities between 15000 A/cm2 and 25000 A/cm2 at 77K in zero field and the maximum values measured so far were 35000 A/cm2.