Superconductivity in Tl-Bi-Ca-Sr-Cu-O and Tl-Bi-Pb-Ca-Sr-Cu-O Systems

Abstract

The influence of the substitution of Bi for Tl on the formation of the superconducting phases in Tl-Bi-Ca-Sr-Cu-O and Tl-Bi-Pb-Ca-Sr-Cu-O systems was investigated. The superconducting (Tl, Bi)Ca 2 Sr 2 Cu 3 O 9 phase with critical temperature of 113 K showing both zero resistivity and diamagnetism is prepared in a Tl-Bi-Ca-Sr-Cu-O system. The crystal structure of this phase is tetragonally symmetric with lattice constants of a =3.813(3) Å and c =15.266(5) Å. The superconducting tetragonal phase of (Tl, Bi, Pb)Ca 2 Sr 2 Cu 3 O 9 is also formed in a Tl-Bi-Pb-Ca-Sr-Cu-O system.