Studies of the formation mechanism of the phase

The formation mechanism of the (Bi, Pb) 2 Sr 2 Ca 2 Cu 3 O 10+δ phase has been studied starting from calcined precursor powders in the Pb-containing as well as in the Pb-free system. In both cases, a nucleation and growth model was found to be suitable to describe the transformations. The formation of the (Bi, Pb) 2 Sr 2 Ca 2 Cu 3 O 10+δ phase inside Ag-sheathed tapes was also investigated. Indications for a nucleation and growth mechanism were found in this case as well.