Superconducting glass ceramics with T c=100 K based on the Bi-Pb-Sr-Ca-Cu-O system

Superconducting glass ceramics of Bi0.8Pb0.2SrCaCu1.5Oy (sample A) and BiPb0.2SrCaCu1.5Oy (sample B) have been prepared by using the melt quenching method. It was found that the volume fraction of the high Tc phases in sample A annealed at 830 or 840 °C for 250 h was much higher than that in sample B. The annealed (840 °C, 250 h) sample A exhibited superconductivity with a Tc (zero) of 100 K and a critical current density (77 K, zero magnetic field) of 120 A/cm2.