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Structure analysis of montmorillonite crystallites by convergent-beam electron diffraction

Published online by Cambridge University Press:  09 July 2018

T. Beermann  and
O. Brockamp
T. Beermann
Affiliation:
Fachgebiet Mineralogie, FB-5, Universität Bremen, Postfach 330 440, D-28334 Bremen, Germany
O. Brockamp*
Affiliation:
Fachgebiet Mineralogie, FB-5, Universität Bremen, Postfach 330 440, D-28334 Bremen, Germany
*
*E-mail: [email protected]
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Abstract

The small particle size and the random stacking of layers has previously hindered systematic structure investigations of montmorillonite. By applying the convergent-beam electron diffraction mode (CBED) of a transmission electron microscope (TEM) with a beam spot of ~800 Å we were able to examine undisturbed areas of montmorillonite crystallites.

Because montmorillonite crystallites are mostly thin particles, kinematic theory can be applied and the CBED patterns can be interpreted directly, provided that the particle thickness remains below the critical value of 350 Å. An average thickness of ~90 Å was calculated here for montmorillonite of bulk samples from X-ray diffraction analysis and lattice-fringe images. However, satisfactory diffraction intensity patterns for quantitative evaluation were obtained only from crystallites with a thickness above the average, which yielded a sufficient scattering volume. These patterns could be described in terms of the kinematic theory and therefore these crystallites were <350 Å thick. Yet, crystallites of adequate thickness were extremely rare in the three samples investigated (Clay Spur, Rock River and Upton, all in Wyoming, USA).

The diffraction intensities from the ab plane of single montmorillonite crystallites of the various origins fit the three structural models for a trans-vacancy distribution, a cis-vacancy distribution or a random-cation distribution within the octahedral sheets. The configuration of the diffraction patterns also shows a 1M symmetry of the layer. Due to the limited data set of CBED patterns, a refinement of the structure could not be achieved. However, energy dispersive X-ray spectroscopy data and computation of the cation–anion distances and valences using the ‘distance valence least square’ program permitted a refinement of the models.

Keywords

montmorillonitestructure analysiselectron diffractionCBED
Type
Research Article
Information
Clay Minerals , Volume 40 , Issue 1 , March 2005 , pp. 1 - 13
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2005

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References

Ahn, J.H. & Peacor, D.R. (1986) Transmission and analytical electron microscopy of the smectite-toillite transition. Clays and Clay Minerals, 34, 165–179.Google Scholar
Ahn, J.H. & Peacor, D.R. (1989) Illite/smectite from Gulf coast shales: A reappraisal of transmission electron microscope images. Clays and Clay Minerals, 37, 542–546.Google Scholar
Besson, G., De La Calle, C., Drits, V.A., Rautureau, M., Tchoubar, C. & Tsipurski, S.I. (1982) X-ray and electron diffraction study of the structure of the Garfield nontronite. Proceedings of the International Clay Conference, 1981. Developments in Sedimentology, 35, pp. 29–40, Elsevier, Amsterdam.Google Scholar
Brindley, G.W. (1980) Order-disorder in clay mineral structures. Pp. 125–196 in: Crystal Structures of Clay Minerals and their X-ray Identification (Brindley, G.W. & Brown, G., editors). Monograph 5, Mineralogical Society, London.CrossRefGoogle Scholar
Cliff, G. & Lorimer, G.W. (1975) The quantitative analysis of thin specimens. Journal of Microscopy, 103, 203-207.Google Scholar
Cowley, J.M. (1975) Diffraction Physics. North-Holland Publishing Company, Amsterdam.Google Scholar
Cowley, J.M. (1992) Convergent beam electron diffraction. Pp. 1–75 in: Electron Diffraction Techniques (Cowley, J.M., editor). Oxford University Press.Google Scholar
Drits, V.A. (1987) Electron Diffraction and High-Resolution Electron Microscopy of Mineral Structures. Springer-Verlag, Berlin.Google Scholar
Drits, V.A., Plancon, A., Sakharov, B.A., Besson, G., Tsipursky, S.I. & Tchoubar, C. (1984) Diffraction effects calculated for structural models of Ksaturated montmorillonite containing different types of defects. Clay Minerals, 19, 541–561.Google Scholar
Drits, V.A., Besson, G. & Muller, F. (1995) An improved model for structural transformations of heat-treated aluminous dioctahedral 2:1 layer silicates. Clays and Clay Minerals, 43, 718–731.CrossRefGoogle Scholar
Gard, J.A. (1971) Interpretation of electron micrographs and electron-diffraction patterns. Pp. 27-78 in: The Electron-Optical Investigations of Clay Minerals (Gard, J.A., editor). Monograph 3, Mineralogical Society, London.Google Scholar
Guthrie, G.D. & Veblen, D.R. (1990) Interpreting onedimensional high-resolution transmission electron micrographs of sheet silicates by computer simulation. American Mineralogist, 75, 276–288.Google Scholar
Güven, N. (1974) Electron-optical investigations on montmorillonites — Cheto, Camp-Berteaux and Wyoming montmorillonites. Clays and Clay Minerals, 22, 155–165.Google Scholar
Güven, N. (1988) Smectites. Pp. 497-559 in: Hydrous Phyllosilicates (Bailey, S.W., editor). Reviews in Mineralogy, 19. Mineralogical Society of America, Washington, D.C.Google Scholar
Hofmann, U., Endell, K. & Wilm, P. (1934) Röntgenographische und kolloidchemische Untersuchungen iiber Ton. Zeitschrift fur Angewandte Chemie, 47, 539–558.Google Scholar
Kroll, H., Maurer, H., Stöckelmann, D., Beckers, W., Fulst, J., Krüsemann, R., Stutenbäumer, T. & Zingel, A. (1992) Simulation of crystal structures by a combined distance-least-squares/valence-rule method. Zeitschrift für Kristallographie, 199, 49–66.Google Scholar
Ma, C., Fitzgerald, J.D., Eggleton, R.A. & Llewellyn, D.J. (1998) Analytical electron microscopy in clays and other phyllosilicates. Loss of elements from a 90-nm stationary beam of 300 keV electrons. Clays and Clay Minerals, 46, 301–316.CrossRefGoogle Scholar
Manceau, A., Lanson, B., Drits, V.A., Chateigner, D., Gates, W.P., Wu, J., Huo, D. & Stucki, J.W. (2000) Oxidation-reduction mechanism of iron in dioctahedral smectites: I. Crystal chemistry of oxidized reference nontronites. American Mineralogist, 85, 133–152.Google Scholar
Marcks, C., Wachsmuth, H. & Reichenbach, H. Graf, v. (1989) Preparation of vermiculites for HRTEM. Clay Minerals, 24, 23–32.Google Scholar
Mering, J. & Oberlin, A. (1971) The smectites. Pp. 193-229 in: The Electron-Optical Investigations of Clay Minerals (Gard, J.A., editor). Monograph 3, Mineralogical Society, London.Google Scholar
Nadeau, P.H., Wilson, M.J., McHardy, W.J. & Tait, J.M. (1984) Interstratified clays as fundamental particles. Science, 225, 923–925.Google Scholar
Peacor, D.R. (1992) Analytical electron microscopy: X-ray analysis. Pp. 124–129 in: Minerals and Reactions at the Atomic Scale: Transmission Electron Microscopy (Buseck, P.R., editor). Reviews in Mineralogy, 27, Mineralogical Society of America, Washington, D.C.Google Scholar
Peacor, D.R. (1998) Implications of TEM data for the concept of fundamental particles. The Canadian Mineralogist, 36, 1397–1408.Google Scholar
Potts, P.J. (1992) Energy dispersive X-ray spectrometry. Pp. 286-325 in: A Handbook of Silicate Rock Analysis (Potts, P.J., editor). Blackie & Son, Ltd, Glasgow, UK.Google Scholar
Tsipursky, S.I. & Drits, V.A. (1984) The distribution of octahedral cations in the 2:1 layers of dioctahedral smectites studied by oblique-texture electron diffraction. Clay Minerals, 19, 177–193.Google Scholar
Vali, H. & Köster, H.M. (1986) Expanding behaviour, structural disorder, regular and random irregular interstratification of 2:1 layer-silicates studied by high-resolution images of transmission electron microscopy. Clay Minerals, 21, 827–859.Google Scholar
Vali, H., Hesse, R. & Martin, R.F. (1994) A TEM-based definition of 2:1 layer silicates and their interstratified constituents. American Mineralogist, 79, 644–653.Google Scholar
Vogt, K. & Köster, H.M. (1978) Zur Mineralogie, Kristallchemie und Geochemie einiger Montmorillonite aus Bentoniten. Clay Minerals, 13, 25–42.Google Scholar
Warr, L.N. & Nieto, F. (1998) Crystallite thickness and defect density of phyllosilicates in low-temperature metamorphic pelites: a TEM and XRD study of claymineral- crystallinity-index standards. The Canadian Mineralogist, 36, 1453–1474.Google Scholar
Zöller, M.H. (1994) Einkristalluntersuchungen an 1M- und 2M1-Illiten durch konvergente Elektronenbeugung. Dr. rer. nat. thesis, Univ. Bremen, Germany.Google Scholar
Zvyagin, B.B. & Pinsker, Z.G. (1949) Electron diffraction study of the montmorillonite structure. Doklady Academii Nauk SSSR, 68, 30–35.Google Scholar
Zvyagin, B.B. (1967) Electron Diffraction Analysis of Clay Mineral Structures. Plenum Press, New York.Google Scholar