Formation of the High-Tc Phase in Rapidly Quenched Bi-Pb-Sr-Ca-Cu-O Ceramics

Abstract
Amorphous ceramics with the composition of Bi2Pb0.4Sr2Ca2Cu3O y were prepared by rapid quenching. The change in crystalline structure during annealing and the effect of the “seeding” with the high-T c phase were investigated. The volume fraction of the high-T c phase increases with annealing time; however, the low-T c phase reaches a maximum value of 38% for 1 h annealing and decreases on prolonged annealing. The formation rate of the high-T c phase changes when the volume of the high-T c phase reaches about 30%. TEM observation shows that the high-T c phase is often located between the low-T c phase and the nonsuperconducting phase. The addition of the seed crystals with the high-T c phase is effective in forming the high-T c phase in shorter annealing times, but a smaller volume fraction of the high-T c phase was obtained after annealing for 50 h.

This publication has 6 references indexed in Scilit: