The Superconductivity in the Bi-Sr-Ln-Cu-O System (Ln=Pr, Nd and La)

Abstract

The superconductivity in samples nominally described as Bi 2 (Sr 1- x Ln x ) 2 Cu 1+ n O y (Ln: lanthanide elements and yttrium: n =0 and 1) was investigated. The effect of an increasing T C compared with that of Bi 2 Sr 2 CuO y was observed for Ln=La, Pr and Nd. The highest end-point of the transition temperature of Bi 2 (Sr 1- x Nd x ) 2 CuO y was 20.4 K with x =0.25. Compounds described as Bi 2 (Sr 0.95 Ln 0.05 ) 2 CuO y (Ln=Pr and Nd) had an onset T C of about 60 K, and small but definite Meissner effects were also observed.