Glass-derived superconducting ceramics with zero resistance at 107 K in the Bi1.5Pb0.5Sr2Ca2Cu3Ox system

Abstract
A melt of composition Bi1.5Pb0.5Sr2Ca2Cu3Ox was fast quenched to form a glass. This was subsequently air annealed and the influence of annealing time and temperature on the formation of various crystalline phases was investigated. X‐ray powder diffraction indicated that none of the resulting samples were single phase. However, for an annealing temperature of 840 °C, the volume fraction of the high Tc phase (isostructural with Bi2 Sr2 Ca2 Cu3O10 ) increased with annealing time. A specimen annealed at this temperature for 243 h followed by slow cooling showed a sharp transition [ΔTc (10–90%) ∼2 K] and Tc (R=0)=107.2 K. To our knowledge, this is the highest Tc yet reported for any superconductor prepared via the glass route.