Energetics of Superstructures in the Bi-Series of Superconducting Compounds

  • Anurag Dwivedi
  • A. N. Cormack


The existence of structural patterns in Bi and Tl-containing superconducting compounds has been well established. In this work, we concentrate on Bi-containing compounds whose stoichiometries are described by the homologous series 3AO-nA’BO3 (3A=Bi2Sr and nA’=SrCa n−1, B=Cu). The first three compounds of this series commonly known as 2021 (Bi2Sr2CuO6), 2122 (Bi2CaSr2Cu2O8), and 2223 (Bi2Ca2Sr2Cu3O10) (corresponding to n = 1, 2, and 3 respectively) have well been studied and the Tc of these compounds has been found to increase with n (at least for n ≤ 3) in the general formula. In other words, Tc apparently is correlated with the number of Cu-O planes present in the perovskite layer of the unit cell.

Structural information on higher order members is, however, incomplete. Based on the structural patterns of the homologous series, model structures and stoichiometries of the first five members (n=1 to 5) were setup. We have investigated the energetics of both model and XRD (where known) structures using atomistic simulation techniques. Preliminary results, using a pairwise potential model, revealed large differences between X-ray and model structures which indicate that distortions and buckling in the planes seen by XRD and which have been ignored in the model structures, are associated with large relaxation energies. These may contribute to the limited phase stability seen in this system. Our results also highlight the need for very accurate interatomic potentials, which we are in the process of developing. An explanation of observed buckling in the Cu-O planes of higher order compounds is also suggested.


Homologous Series Interatomic Potential Strontium Titanate Ceramic Superconductor Body Potential 
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  1. [1]
    Davies, A. H. and Tilley, J. D., Nature, Vol. 326, 1987.Google Scholar
  2. [2]
    Catlow, C. R. A., in Mass Transport in Solids, edited by F. Beniere and C. R. A. Catlow, pl, Plenum (1983).Google Scholar
  3. [3]
    Catlow, C. R. A. and Mackrodt, W. C., eds. Computer Simulation of Solids, Lecture Notes in Physics, 166, Springer, (1982).Google Scholar
  4. [4]
    Dick, B. G. and Overhouser, A. W., Phys. Rev., 112 [1], 90 (1958).ADSCrossRefGoogle Scholar
  5. [5]
    Catlow, C. R. A., Proc. Roy. Soc., A, 353, 533 (1977).ADSGoogle Scholar
  6. [6]
    Lewis, G. V. and Catlow, C. R. A., 1985, J. Phys. C:Solid State Phys., 18, 1149 (1985).ADSCrossRefGoogle Scholar
  7. [7]
    Cormack, A. N., Solid State Ionics, 8, 187 (1983).CrossRefGoogle Scholar
  8. [8]
    Parker, S. C., Computer Modeling of Minerals, Ph. D. Thesis, Univ. of London, London, UK, (1983).Google Scholar
  9. [9]
    Jacobs, P. W. M., and MacDonaill, D. A., Solid State Ionics, 23, 279 (1987).Google Scholar
  10. [10]
    Islam, M. S., Leslie, M., Tomlinson, S. M., and Catlow, C. R. A., J. Phys. C: Solid State Phys. 21 (1988), L109 - L117.ADSCrossRefGoogle Scholar
  11. [11]
    Smyth, D., M., “Structural Patterns in High T, Superconductors”, Preprint (To be published in the Proceedings of the Superconductor Symposium, 90th Annual Meeting of the American Ceramic Society, Cincinnati, May 1 - 5, 1988 ).Google Scholar
  12. [12]
    Sleight, A. W., Subramanian, M. A., and Torardi, C. C., Mat. Res. Bulletin, Vol XIV, No. 1, pp 45 - 47, (1989).ADSGoogle Scholar
  13. [13]
    Matheis, D. P., McIntyre, P., Snyder, R. L., “X-ray Powder Diffraction Standards for Copper Oxide Based Superconductors”, Paper presented in the 91st annual meeting of Amer. Cer. Soc., Indianapolis, IN, April 23 - 27, 1989.Google Scholar
  14. [14]
    Udaykumar, K. R., and Cormack, A. N., J. Amer. Cer. Soc. 71, C-469(1988).Google Scholar

Copyright information

© Springer Science+Business Media New York 1990

Authors and Affiliations

  • Anurag Dwivedi
    • 1
  • A. N. Cormack
    • 1
  1. 1.NYS College of CeramicsAlfred UniversityAlfredUSA

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