UNIT-CELL PARAMETER DISPLACEMENT WITH TEMPERATURE AND OXYGEN CONTENTSIN A HIGH-T-C PHASE PB-BI-SR-CA-CU-O SYSTEM SUPERCONDUCTOR

The ceramic superconductors were prepared by sintering a powder compac t with a composition of Pb0.4Bi2Sr2Ca2Cu3Ox at 1123 K. During the fina l firing process of this solid state reaction, the oxygen concentratio n of the atmosphere in the furnace was controlled at 0,10 and 20%. In this report, the expansion and contraction behaviors of the PBSCCO uni t cell in the temperature range from 77 to 289 K, in connection with t he O-2 partial pressures, are described. The powder X-ray diffraction patterns were carefully obtained under each experimental condition, an d the diffracted intensity data were analyzed using the Rietveld metho d. (C) 1998 Published by:Elsevier Science Ltd. All lights reserved.