Crystal structure of Tl/sub 2/Ba/sub 2/Ca/sub 2/Cu/sub 3/O/sub 10/, a 125 K superconductor

Journal Article · Fri Apr 29 04:00:00 EDT 1988 · Science (Washington, D.C.); (United States)

DOI:https://doi.org/10.1126/science.240.4852.631· OSTI ID:7009261

Torardi, C C; Subramanian, M A; Calabrese, J C; Gopalakrishnan, I; Morrissey, K J; Askew, T R; Flippen, R B; Chowdhry, U; Sleight, A W

There is now a new series of high-temperature superconductors that may be represented as (A/sup III/O)/sub 2/A/sub 2//sup II/ Ca/sub n-1/Cu/sub n/O/sub 2+2n/ where A/sup III/ is Bi or Tl, A/sup II/ is Ba or Sr, and n is the number of Cu-O sheets stacked consecutively. There is a general trend toward higher transition temperatures as n increases. The highest n value for a bulk phase is three and is found when A/sup III/ is Tl. This compound, Tl/sub 2/Ba/sub 2/Ca/sub 2/Cu/sub 3/O/sub 10/, has the highest transition temperature (approx. 125 K) of any presently known bulk superconductor. The structure of Tl/sub 2/Ba/sub 2/Ca/sub 2/Cu/sub 3/O/sub 10/ has been determined from single-crystal x-ray diffraction data and is tetragonal, with a = 3.85 A and c = 35.9 A. No superstructure is observed, and the material is essentially twin-free. Electronic microscopy in the Tl/Ba/Ca/Cu/O system has revealed intergrowths where n = 5; such regions may well be responsible for the superconducting onset behavior observed in this system at about 140 K. 14 references, 4 figures, 4 tables.

• Research Organization: E. I. du Pont de Nemours and Co., Wilmington, DE (USA)
• OSTI ID: 7009261
• Journal Information: Science (Washington, D.C.); (United States), Journal Name: Science (Washington, D.C.); (United States) Vol. 240; ISSN SCIEA
• Country of Publication: United States
• Language: English

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