Structural characterisations of the NaxSi136 and Na8Si46 silicon clathrates using the Rietveld method

(Note: The full text of this document is currently only available in the PDF Version )

Edouard Reny, Pierre Gravereau, Christian Cros and Michel Pouchard


Abstract

The crystal structure of the non-stoichiometric NaxSi136 silicon clathrate has been refined using the Rietveld method, in order to determine accurately the distribution of the sodium atoms within the two available sites. In agreement with the previous data, it was found that for x≤8, the alkali atoms occupy exclusively, and not only preferentially the eight larger Si28 sites. For 8<x<24, the filling of the sixteen smaller Si20 cages occurs gradually with increasing x, and a slight increase of the unit cell parameter is then observed. The crystal structure of the stoichiometric Na8Si46 clathrate, which is present as impurity in the studied samples, has also been refined.


References

  1. C. Cros, M. Pouchard and P. Hagenmuller, C. R. Acad. Sci., 1965, 260, 4764 Search PubMed.
  2. J. S. Kasper, P. Hagenmuller, M. Pouchard and C. Cros, Science, 1965, 150, 1713 CAS.
  3. C. Cros, M. Pouchard and P. Hagenmuller, J. Solid State Chem., 1970, 2, 570 CAS.
  4. C. Cros and J. C. Benejat, Bull. Soc. Chim. Fr., 1972, 5, 1739.
  5. J. Gallmeier, H. Schäfer and A. Weiss, Z. Naturforsch. Teil B, 1967, 22, 1080 Search PubMed.
  6. J. Gallmeier, H. Schäfer and A. Weiss, Z. Naturforsch. Teil B, 1969, 24, 665 Search PubMed.
  7. C. Cros, PhD Thesis, 1970, Univ. Bordeaux I, no. 291.
  8. N. F. Mott, J. Solid State Chem., 1973, 6, 348 CAS.
  9. K. E. Sim, PhD Thesis, 1983, Imperial College of Science and Technology, London.
  10. G. B. Adams, M. O'Keefe, A. A. Demkov, O. F. Sankey and Y. M. Huang, Phys. Rev. B, 1994, 49, 8048 CrossRef CAS.
  11. A. A. Demkov, O. F. Sankey, K. E. Schmidt, G. B. Adams and M. O'Keefe, Phys. Rev. B, 1994, 50, 17001 CrossRef CAS.
  12. S. Saito and A. Oshiyama, Phys. Rev. B, 1995, 51, 2628 CrossRef CAS.
  13. V. I. Smelyanski and J. S. Tse, Chem. Phys. Lett., 1997, 264, 459 CrossRef.
  14. H. Kawaji, H. Horie, S. Yamanaka and M. Ishikawa, Phys. Rev. Lett., 1995, 74, 1427 CrossRef CAS.
  15. S. Yamanaka, H. Horie, H. Kawaji and M. Ishikawa, Eur. J. Solid State Inorg. Chem., 1995, 32, 799 CAS.
  16. P. Mélinon, P. Kéghélian, X. Blase, J. Le Brusc, A. Perez, E. Reny, C. Cros and M. Pouchard, Phys. Rev. Lett., to be published Search PubMed.
  17. Y. Guyot, B. Champagnon, E. Reny, C. Cros, M. Pouchard, P. Melinon, A. Perez and I. Gregora, Phys. Rev. B, 1998, 57, 9475 CrossRef.
  18. F. Shimizu, Y. Maniwa, K. Kume, H. Kawaji, S. Yamanaka and M. Ishikawa, Synth. Met., 1997, 86, 2141 CrossRef CAS.
  19. S. Roy, K. E. Sim and A. D. Caplin, Philos. Mag. B, 1992, 65, 1445 Search PubMed.
  20. M. Menon, E. Richter and K. R. Subbaswamy, Phys. Rev. B, 1997, 56, 1290 CrossRef CAS.
  21. E. Reny, M. Ménétrier, C. Cros, M. Pouchard and J. Sénégas, C.R. Acad. Sci., Ser. IIc, 1998, 1, 129 Search PubMed.
  22. J. Gryko, P. F. McMillan and O. F. Sankey, Phys. Rev. B, 1996, 54, 3037 CrossRef CAS.
  23. J. Gryko, P. F. McMillan, R. F. Marzke, A. P. Dodokin, A. A. Demkov and O. F. Sankey, Phys. Rev. B, 1998, 57, 4172 CrossRef CAS.
  24. J. Rodriguez-Carvajal, A program for Rietveld refinement and pattern matching analysis, Collected Abstracts of Powder Diffraction Meeting, 1990, Toulouse, p. 127 Search PubMed.
  25. J. F. Berar and P. Lelann, J. Appl. Crystallogr., 1991, 24, 1 CrossRef CAS.
  26. G. M. Sheldrick, SHELXL 93, a program for the refinement of crystal structure, Univ. Göttingen, 1993.
  27. J. E. Huheey, E. A. Keiter and R. L. Keiter, Chimie Inorganique, De Boeck, University, Bruxelles, 1996 Search PubMed.
Click here to see how this site uses Cookies. View our privacy policy here.