The 110-K superconducting transition in the Bi-Ca-Sr-Cu-O system has been observed by many researchers. However, not even a filamentary path has been obtained connecting these regions in multiphase, polycrystalline samples. We have achieved zero resistance at temperatures exceeding 100 K in several samples by adding Pb to the system. The highest value we have observed is $T_c$,zero=107 K for ${\mathrm{Bi}}_{1.8}$${\mathrm{Pb}}_{0.2}$${\mathrm{Ca}}_2$${\mathrm{Sr}}_2$${\mathrm{Cu}}_3$${\mathrm{O}}_{\mathit{y}}$.

• Received 21 April 1988

DOI:https://doi.org/10.1103/PhysRevB.38.5016