SINTERING EFFECT ON BI(PB) SR CA CU O HIGH-T-C SUPERCONDUCTORS

D.c. electrical resistivity, a. c. magnetic susceptibility and X-ray d iffraction techniques have been used to investigate the superconductiv e and structural properties in the systems Bi1.6Pb0.4Sr2Ca2Cu4.5OY and Bi1.6Pb0.2Sr2Ca2Cu4Oy. It is observed that the preparation method and heating methodology affect the properties of materials. Step sinterin g is of greater value for magnetic properties of the samples whereas p rolonged sintering makes the systems more metallic and a smooth variat ion in resistivity with temperature is observed. The superconducting p hase identified by X-ray diffraction analysis is mainly the high-T-c p hase in all the samples. Resistivity and susceptibility measurements a lso indicate primarily the high-T-c phase. (C) 1998 Chapman & Hall.