Zero resistance at 107 K in the (Bi,Pb)-Ca-Sr-Cu oxide system

Abstract

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 ${\mathrm{Bi}}_{1.8}$ ${\mathrm{Pb}}_{0.2}$ ${\mathrm{Ca}}_2$ ${\mathrm{Sr}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_{\mathit{y}}$.