Importance of Avrami Index in the processing of bismuth based high temperature superconductors

It is well known that processing of Bismuth based high Tc perovskites is difficult and often results in only multiphase systems. Innumerous reports on parameters like annealing temperature, annealing time, selection of right combination of elements and addition of dopants like Pb are available since a long time and still the synthesis of single phase High Tc is not an easy task in contrast to the synthesis of Yitrium based cuprates. Here we report for the first time, how the knowledge of Avrami Index (dimensionality of crystal growth) provides critical insight in selecting the right mixture of Lead doped Bismuth cuprates for forming a highly single phase and high Tc compound through glassy precursor route.