Crystal Structures and Electrical Properties of Tl-Ba-Ca-Cu-O Superconductors

Abstract

Three samples having general composition Tl₂Ba₂Ca_n-1Cu_n0_4+2n (n=1, 2 and 3) were synthesized, and were examined their electrical properties and crystal structures. Rietveld refinement revealed that as n increased the lattice parameter, a, and interatomic distance Cu-O(2) became shorter, and the Tl-O and Ba-O layers showed a tendency to become flatter. Possible substitution of about 10% of the Ca-site with Tl ion in the 2212 and 2223 phases was also suggested.