Superconductivity above 100 K by Pr substitution in the two-copper-layer Bi-Pb-Sr-Ca-Cu-O system.

Abstract

The effect of Pr substitution on superconducting and transport properties has been studied in the Bi-Pb-Sr-Ca-Cu-O system. We obtain samples with structure similar to the 80-K phase for ${\mathit{T}}_{\mathit{c}}$(R=0) up to 102 K. In particular, the highest ${\mathit{T}}_{\mathit{c}}$ (102 K) is obtained with the nominal composition ${\mathrm{Bi}}_{1.7}$${\mathrm{Pb}}_{0.3}$${\mathrm{Sr}}_{1.8}$${\mathrm{Pr}}_{0.2}$${\mathrm{Ca}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{10+\mathit{y}}$, showing an 80-K single phase. We believe that the variation of ${\mathit{T}}_{\mathit{c}}$ is determined by changes in the hole density in the Cu-${\mathrm{O}}_{2}$ planes due to the substitution of Pr into Sr sites.