Intergrowth Structures in Superconductor Tl-Ba-Ca-Cu-O Oxides

Abstract

Direct read-out of metal atom coordinates from HREM images was performed on superconductive Tl-Ba-Ca-Cu-O (TBCCO) oxide crystals. The technique permits examination, in a quantitative fashion, of crystal structures including stacking disorders. Some ordered intergrowth structure for TBCCO oxides, beside the Tl₂Ba₂CaCu₂O_8+x (2212) and Tl₂Ba₂Ca₂Cu₃O_10+x (2223) phases, were observed, and their structure were identified as sequences of structure with a single Tl-O sheet instead of double Tl₂O₂ sheets, a chemical formula TlBa₂Ca₂Cu₃O_9+x , has been confirmed.