The stability of high-T c phase in Bi1.6Pb0.4Sr2Ca2Cu3Oz compounds prepared by hot isostatic pressing

By using a sequence of hot isostatic pressing (HIP) and intermediate cold pressing, it has been possible to produce high-density Bi-based superconductors containing almost 100% high-T_c 2223 phase, without any post-fabrication heat treatment. The X-ray data showed no decomposition of high-T_c phase in hot isostatically pressed Bi-based superconductors. By using this technique, Bi_1.6Pb_0.4Sr₂Ca₂Cu₃O_z (where Z≈10) superconductors could be densified to 6.06 g cm^?3 at an HIP temperature of 850 °C, and at an HIP temperature of 870 °C the density was close to 6.15 g cm^?3. These densities could be compared with about 3 to 4 g cm^?3 obtained for conventionally sintered compounds. X-ray diffraction data at various stages of fabrication, microstructure and electrical resistivity data are presented.