Towards the rapid synthesis of pure 2223 powders with Bi 2− xPb xSr 2Ca 2Cu 3O y compositions by semi-wet methods : I. Reaction sequence for Pb 0.2SrCa(CO 3) 2.2 precursor

Abstract

A new semi-wet route to the synthesis of leaded 2223 powders free from 2201 and 2212 phases within the shortest heat treatment duration is presented for a stoichiometric nominal composition. By following the sequence of solid state thermochemical reactions, it is shown that Ca 2PbO 4 and 2212, formed in the early stages of reaction, in conjunction with CuO play the most crucial role in accelerating the formation of the 2223 phase. The results of the present semi-wet route are compared with those obtained using other semi-wet routes.