The Crystal Structures and Powder Diffraction Patterns of the Bismuth and Thallium Ruddlesden-Popper Copper Oxide Superconductors

Abstract

This paper contains a review and explanation of the super conducting Ruddlesden-Popper phases in the systems Bi-Sr-Ca-Cu-O and Tl-Ba-Ca-Cu-O. Calculated powder X-ray patterns for the phases Bi-2201, 2212, 2223, and 2234 (where the numbers refer to the stoichiometric ratios of Bi:Sr:Ca:Cu) and Tl-1201, 1212, 1223, 1234, 2201, 2212, 2223, and 2234 (here the numbers refer to the molar ratios of Bi:Ba:Ca:Cu) generated from the reviewed crystal structures are presented. Observed powder patterns for Tl-2201, Tl-2212, Bi-2201 and Bi-2212 are included and compared to the calculated patterns of these phases.

Phase Diagram Studies in the System Tl2O3–BaO–CaO–CuO–Ag

“…[1][2][3][4] For the preparation of defined single-phase or multiphase ceramics of these compounds, knowledge of the phase equilibria of the system Tl 2 O 3 -BaO-CaO-CuO is of great importance. To simulate the preparation conditions during the "oxide powder in tube" processing of high-temperature superconducting Ag-sheathed tapes (OPIT processing 5 ) the phase equilibria were studied in the presence of about 80 vol% Ag.…”

Bi-based high Tc superconducting fibers by melt extraction

“…The 2212 phase can he generated trom the 2201 phase by adding a calcium and The lattice parameters of the Bi-Sr-Ca-Cu-O compounds are tabulated in by Matheis and Snyder (1990) and was used as a reference for mucb of the characterisation performed in ihis work.…”

Melting and vaporization of the 1223 phase in the system (Tl-Pb-Ba-Sr-Ca-Cu-O)

“…This compound is well known as one of the Ruddelsden-Popper series of homologous compounds, TlBa 2 Ca n −1 Cu n O 2 n +3 where n = number of Cu-O layers [3], in which an alternating structural arrangement of rocksalt and perovskite layers is found. TlBa 2 Ca 2 Cu 3 O x is tetragonal with space group I4/mmm, a = 3.847 Å and c = 15.89 Å [4].…”