THE STABILITY OF HIGH-TC PHASE IN BI1.6PB0.4SR2CA2CU3OZ COMPOUNDS PREPARED BY HOT ISOSTATIC PRESSING

By using a sequence of hot isostatic pressing (HIP) and intermediate c old pressing, it has been possible to produce high-density Bi-based su perconductors containing almost 100% high-Tc 2223 phase, without any p ost-fabrication heat treatment. The X-ray data showed no decomposition of high-Tc phase in hot isostatically pressed Bi-based superconductor s. By using this technique, Bi1.6Pb0.4Sr2Ca2Cu3OZ (where Z almost-equa l-to 10) superconductors could be densified to 6.06 g cm-3 at an HIP t emperature of 850-degrees-C, and at an HIP temperature of 870-degrees- C the density was close to 6.15 g cm-3. These densities could be compa red with about 3 to 4 g cm-3 obtained for conventionally sintered comp ounds. X-ray diffraction data at various stages of fabrication, micros tructure and electrical resistivity data are presented.