Sintering effect on Bi(Pb)-Sr-Ca-Cu-O high-T/sub c/ superconductors

DC electrical resistivity, AC magnetic susceptibility and X-ray diffraction techniques have been used to investigate the superconductive and structural properties in the systems Bi/sub 1.6/Pb/sub 0.4/Sr/sub 2/Ca/sub 2/Cu/sub 4.5/O/sub y/ and Bi/sub 1.6/Pb/sub 0.2/Sr/sub 2/Ca/sub 2/Cu/sub 4/O/sub y/. It is observed that preparation method and heating methodology effect the properties of materials. Prolonged sintering makes the system more metallic like and smooth variation in resistivity with temperature, is observed. The superconducting phase identified by XRD analysis is mainly the high-T/sub c/ phase in all the samples. Resistivity and susceptibility measurements also indicate primarily the high-T/sub c/ phase. (author)