Growth of the 2223 Phase in Bi-Sr-Ca-Cu Oxide Films under a Controlled Pb Potential

Growth of the 2223 phase in Bi-Sr-Ca-Cu oxide films has been found to increase significantly by annealing the Pb-free, sputter-deposited amorphous film with a Pb source pellet, i.e., Bi-Pb-Sr-Ca-Cu oxide, in a closed Au capsule kept at temperature around 850°C. It is shown that, under an appropriate Pb potential, the 2223 phase grows from the amorphous phase via the intermediately formed 2212 phase, but does not grow when the 2212 phase is formed prior to the Pb treatment. The effects of heating rate and film thickness on the growth of the 2223 phase are discussed.