Jointing of Bi-2223 sintered bulk using superconductor paste

In order to fabricate large sized superconductor bulk, small pieces of sint ered bulks were jointed using superconductor paste prepared with mixture of calcined powder and organic vehicle. The superconductor paste was sprayed several times on the surface of the bulks. Four Bi-2223 bulks, 20 x 10 x 2 mm(3), were stuck to 20 mm square plate and 4 mm thick. This sample was sin tered at 840 degreesC for 50 h and then, intermediately subjected to CIP an d sintered again. After three times of CIP and sintering, the superconducti ng properties of T-c = 104 K and J(c) = 7000 A/cm(2) were obtained for the sample, which were almost the same as those of the sintered bulks. The magn etic property was measured at 77 K. When a uniform magnetic field was appli ed perpendicular to the plate surface, two-dimensional distribution of the magnetic flux density over the sample surface was measured with a Hall prob e in the direction perpendicular to the sample surface. The flux leak of de nsity 2 mT was observed at the center of the jointed sample where an extern al magnetic field of 15 mT was applied. (C) 2001 Elsevier Science B.V. All rights reserved.