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Relationships between the medium-range structure of glasses and crystals

Published online by Cambridge University Press:  05 July 2018

P. H. Gaskell*
Affiliation:
Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE, UK
*
* E-mail: phg1@cam.ac.uk

Abstract

The known structure of a crystalline phase is almost always useful in investigating the unknown structure of the compositionally equivalent glass. For the local environment around elements like Si, B and P, the correspondence between site geometry and symmetry can be impressively close. Beyond near neighbours, any relationship becomes less obvious – at least in real-space data. Progress in understanding the medium-range structures of glasses has been painfully slow as a result. One essential clue is given by reciprocal-space features at low Q (scattering vector) in X-ray or neutron scattering data, which are clearly related to the medium-range structure. Interpretation of these features as ‘quasi-Bragg’ scattering allows direct comparison between the structures of the glass and equivalent crystalline phases. Applications of this method will be illustrated in borates and silicates, together with some chalcogenide glasses. Correspondence between low-Q features for these glasses and compositionally-equivalent crystals is qualitatively good. In some cases there is semi-quantitative agreement too. Thus the essential flavour of the medium-range structure of several typical glasses appears to be interpretable, rather easily.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2000

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References

Armand, P., Ibanez, A., Tonnerre, J.-M., Bouchet-Fabre, B. and Philippot, E. (1997) Structural characteristics of Ag2GeS3 glass by anomalous wide angle X-ray scattering. Phys. Rev. B, 56, 10852–8.CrossRefGoogle Scholar
Cormier, L., Gaskell, P.H. and Creux, S. (1999) Comparison of the low-Q features in diffraction data for silicate glasses and crystals containing Sr or Ba. J. Non-Cryst. Solids, 248, 8491.CrossRefGoogle Scholar
Dittmar, G. and Schafer, H. (1975) Die Kristallstruktur von HT GeS2 . Acta Crystallogr., B31, 2060–4.CrossRefGoogle Scholar
Fayos, R., Bermejo, F.J., Dawidowski, J., Fischer, H.E. and Gonzalez, M.A. (1996) Direct experimental evidence of the relationship between intermediaterange order in topologically disordered matter and discernable feature in the static structure factor. Phys. Rev. Lett., 77 3823–26.CrossRefGoogle Scholar
Gaskell, P.H. (1995) Structure, glass formation and properties. J. Non-Cryst. Solids, 192,193, 9–22.CrossRefGoogle Scholar
Gaskell, P.H. (1997) Low-Q features in diffraction data for borate glasses and crystals – an examination of similarities in medium-range structures. Pp. 71–9 in: 2nd Int. Conf. on Borate Glasses, Crystals and Melts (Wright, A.C. and Feller, S.A., editors). Society of Glass Technology, Sheffield, UK.Google Scholar
Gaskell, P.H. (1998) The structure of simple glasses: randomness or pattern-the debate goes on. Glass Phys. Chem., 24, 180–8.Google Scholar
Gaskell, P.H. and Wallis, D.J. (1996) Medium-range order in silica, the canonical network glass. Phys. Rev. Lett., 76, 66–9.CrossRefGoogle ScholarPubMed
Gladden, L.F. (1990) Medium-range order in v-SiO2 . J. Non-Cryst. Solids, 119, 318–30.CrossRefGoogle Scholar
Hannon, A.C., Vessal, B. and Parker, J.M. (1992) The structure of alkali silicate glasses. J. Non-Cryst. Solids, 150, 97102.CrossRefGoogle Scholar
Lee, J.H., Pradel, A., Hannon, A.C., Ribes, M. and Elliott, S.R. (1996) Structural determination of Ag-Ge-S glasses using neutron diffraction. Phys. Rev., B54, 3895–909.CrossRefGoogle Scholar
Misawa, M., Price, D. and Suzuki, K. (1980) The shortrange structure of alkali silicate glasses by pulsed neutron total scattering. J. Non-Cryst. Solids, 37, 85–98.CrossRefGoogle Scholar
Nagel, A. and Range, K.-J. (1978) Verbindungsbildung im System Ag2S-GeS2-AgI (Compound formation in the system Ag2S-GeS2-AgI). Z. Naturf., 33B, 1461–4.CrossRefGoogle Scholar
Uhlrig, H., Hoffmann, M.J., Lamparter, H.-P., Aldinger, F., Bellissent, R. and Steeb, S. (1992) J. Amer. Ceram. Soc., 79, 2833.CrossRefGoogle Scholar
Wanless, A.J., Wright, A.C., Sinclair, R.N., Feller, S.A., Williams, R.B., Johanson, B.C. and Mayhew, M.T. (1997) A proposed relationship between the position of the first neutron diffraction peak for alkali borate glasses and the separation between the modifying cations as found from density measurements. Pp. 506–12 in: 2nd Int. Conf. on Borate Glasses, Crystals and Melts (Wright, A.C. and Feller, S.A., editors). Society of Glass Technology, Sheffield, UK.Google Scholar
Wilson, M. and Madden, P.A. (1998) Voids, layers and the First Sharp Diffraction peak in ZnCl2 . Phys. Rev. Lett., 80, 532–5.CrossRefGoogle Scholar
Zhao, J., Gaskell, P.H., Cluckie, M.M. and Soper, A.K. (1998) A neutron diffraction isotopic substitution study of the structure of Li2O.2SiO2 glass. J. Non- Cryst. Solids, 234, 721–7.CrossRefGoogle Scholar