A comparison of the properties of Bi-2223 precursor powders synthesized by various methods

We report on the study of the (Bi,Pb)(2)Sr2Ca2Cu3Ox precursor powders prepared by coprecipitation, citrate gel, and spray pyrolysis. All powders had the same starting nominal compositions, and were calcined under the same conditions. The properties of the precursor powders are compared. It is found that the phase compositions of these precursor powders are not identical, and the powder prepared by spray pyrolysis seems to be particularly different. Moreover, the observation of the Bi-2223 phase formation reveals that the spray pyrolysis powder transforms to Bi-2223 far faster than the other powders. (C) 2001 Elsevier Science Ltd. All rights reserved.