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High-Resolution Transmission Electron Microscopy and Electron Diffraction of Mixed-Layer Illite/Smectite: Experimental Results

Published online by Cambridge University Press:  02 April 2024

David R. Veblen ,
George D. Guthrie Jr. ,
Kenneth J. T. Livi  and
Robert C. Reynolds Jr.
David R. Veblen
Affiliation:
Department of Earth & Planetary Sciences, The Johns Hopkins University, Baltimore, Maryland 21218
George D. Guthrie Jr.
Affiliation:
Department of Earth & Planetary Sciences, The Johns Hopkins University, Baltimore, Maryland 21218
Kenneth J. T. Livi
Affiliation:
Department of Earth & Planetary Sciences, The Johns Hopkins University, Baltimore, Maryland 21218
Robert C. Reynolds Jr.
Affiliation:
Department of Geology, Dartmouth College, Hanover, New Hampshire 03755
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Abstract

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High-resolution transmission electron microscopy (HRTEM) and electron diffraction experiments have been performed on R1 and R> 1 illite/smectite (I/S) samples that from X-ray powder diffraction (XRD) experiments appear to contain well-ordered layer sequences. The HRTEM images confirmed earlier computer image simulations, which suggested that periodicities due to I/S ordering can be imaged in TEM instruments of moderate resolution. The experiments also confirmed that in instruments of this sort, the strongest contrast arising from the compositional difference between I and S layers occurs under rather unusual imaging conditions of strong overfocus. Some selected-area electron diffraction (SAD) patterns showed additional diffraction spots consistent with R1 and R3 ordering. SAD patterns and cross-fringes arising in HRTEM images from non-00l reciprocal lattice rows indicated that the stacking vectors of most adjacent 2:1 layers were not randomly oriented with respect to each other. Thus, the I/S was not fully turbostratic, but instead consisted of very thin, coherently stacked crystallites that extended across the fundamental particles postulated by Nadeau and coworkers.

S/(I + S) ratios were determined for about seventy HRTEM images obtained and interpreted by three different TEM operators. These ratios were consistent with those obtained from standard XRD procedures, suggesting that results obtained by XRD can be used to infer the initial structural state of mixed-layer I/S prior to treatment of samples for XRD experiments. The HRTEM experiments thus demonstrated that the two specimens examined consisted of ordered I/S existing as small crystals, most of which contained more layers than the fundamental particles of Nadeau and coworkers. The non-turbostratic stacking suggests an energetic interaction between the individual fundamental particles, leading to at least two alternative thermodynamic descriptions of these materials. Although the I/S crystals in the present experiments probably were disaggregated into fundamental particles during sample preparation for XRD, the I/S crystals appear to have separated only along the smectite interlayers. If the term “fundamental particle” is to be used for primary, untreated I/S, its original definition should be modified to include not only free particles, but also those that occur as layers within small crystals. It further should be recognized that these particles can interact thermodynamically and crystallographically with their neighbors.

Keywords

Electron diffractionFundamental particleHigh-resolution transmission electron microscopyIllite/smectiteInterstratificationSmectite
Type
Research Article
Information
Clays and Clay Minerals , Volume 38 , Issue 1 , February 1990 , pp. 1 - 13
Copyright
Copyright © 1990, The Clay Minerals Society

References

Ahn, J. H. and Buseck, P. R. (1990) Layer-stacking sequences and structural disorder in mixed-layer illite/smectite: Image simulations and HRTEM imaging: Amer. Mineral. 75, (in press).Google Scholar
Ahn, J. H. and Peacor, D. R., 1986 Transmission and analytical electron microscopy of the smectite-to-illite transition Clays & Clay Minerals 34 165 – 179.Google Scholar
Ahn, J. H. and Peacor, D. R., 1986 Transmission electron microscope data for rectorite: Implications for the origin and structure of “fundamental particles” Clays & Clay Minerals 34 180 – 186.Google Scholar
Ahn, J. H. and Peacor, D. R. (1989) Mixed-layer illite/smectite from Gulf Coast shales: A reappraisal of TEM images: Clays & Clay Minerals 37, (in press).Google Scholar
Altaner, S. P. and Bethke, C. M., 1988 Interlayer order in illite/smectite Amer. Mineral. 73 766 – 774.Google Scholar
Altaner, S. P., Weiss, C. A. Jr. and Kirkpatrick, R. J., 1988 Evidence from 2,Si NMR for the structure of mixed-layer illite/smectite clay minerals Nature 331 699 – 702.CrossRefGoogle Scholar
Eberl, D. D. and Środoń, J., 1988 Ostwald ripening and interparticle-diffraction effects for illite crystals Amer. Mineral. 73 1335 – 1345.Google Scholar
Enüstün, B. V. and Turkevich, J., 1960 Solubility of fine particles of strontium sulfate J. American Chem. Soc. 82 4502 – 4509.CrossRefGoogle Scholar
Guthrie, G. D. Jr. and Veblen, D. R., 1988 Simulated highresolution transmission electron microscope images of mixed-layer illite/smectite clays Prog, and Abstracts, The Geochemical Society V. M. Goldschmidt Conf. 45.Google Scholar
Guthrie, G. D. Jr. and Veblen, D. R., 1989 High-resolution transmission electron microscopy of mixed-layer illite/smectite: Computer simulations Clays & Clay Minerals 37 1 – 11.CrossRefGoogle Scholar
Guthrie, G. D. Jr. Veblen, D. R., Coyne, L. M., Blake, D. F. and McKeever, S., 1989 High-resolution transmission electron microscopy applied to clay minerals Spectroscopic Characterization of Minerals and their Surfaces 75 – 93.CrossRefGoogle Scholar
Guthrie, G. D. Jr. and Veblen, D. R. (1989c) Interpreting one-dimensional high-resolution transmission electron micrographs of sheet silicates by computer simulation: Amer. Mineral. 74, (in press).Google Scholar
Hirsch, P., Howie, A., Nicholson, R. B., Pashley, D. W. and Whelan, M. J., 1977 Electron Microscopy of Thin Crystals 2nd ed. Florida Robert E. Krieger Publishing Company, Malabar.Google Scholar
Inoue, A., Minato, H. and Utada, M., 1978 Mineralogical properties and occurrence of illite/montmorillonite mixed layer minerals from Miocene volcanic glass in Waga-Omono district Clay Sci. 5 123 – 136.Google Scholar
Inoue, A. and Utada, M., 1983 Further investigations of a conversion series of dioctahedral mica/smectites in the Shinzan hydrothermal alteration area, northeast Japan Clays & Clay Minerals 31 401 – 412.CrossRefGoogle Scholar
Inoue, A., Velde, B., Meunier, A. and Touchard, G., 1988 Mechanism of illite formation during smectite-to-illite conversion in a hydrothermal system Amer. Mineral. 73 1325 – 1334.Google Scholar
Keller, W. D., Reynolds, R. C. and Inoue, A., 1986 Morphology of clay minerals in the smectite-to-illite conversion series by scanning electron microscopy Clays & Clay Minerals 34 187 – 197.CrossRefGoogle Scholar
Livi, K. J. T. and Veblen, D. R., 1987 “Eastonite” from Easton, Pennsylvania: A mixture of phlogopite and a new form of serpentine Amer. Mineral. 72 113 – 125.Google Scholar
Mackinnon, I. D. R., 1987 The fundamental nature of illite/smectite mixed-layer clay particles: A comment on papers by P. H. Nadeau and coworkers Clays & Clay Minerals 35 74 – 76.CrossRefGoogle Scholar
Méring, J., Oberlin, A. and Gard, J. A., 1971 The smectites The Electron Optical-Investigation of Clays London Mineralogical Society 193 – 229.CrossRefGoogle Scholar
Nadeau, P. H., 1985 The physical dimensions of fundamental clay particles Clay Miner. 20 499 – 514.CrossRefGoogle Scholar
Nadeau, P. H., Wilson, M. J., McHardy, W. J. and Tait, J. M., 1984 Interstratifled XRD characteristics of physical mixtures of elementary clay particles Clay Miner. 19 67 – 76.CrossRefGoogle Scholar
Nadeau, P. H., Wilson, M. J., McHardy, W. J. and Tait, J. M., 1984 Interparticle diffraction: A new concept for interstratifled clays Clay Miner. 19 757 – 769.CrossRefGoogle Scholar
Nadeau, P. H., Wilson, M. J., McHardy, W. J. and Tait, J. M., 1984 Interstratifled clays as fundamental particles Science 225 923 – 925.CrossRefGoogle ScholarPubMed
O’Keefe, M. A., 1984 Electron image simulation: A complementary image processing technique Electron Optical Systems Chicago AMF O’Hare 209 – 220.Google Scholar
Schock, Robert N., 1985 Point Defects in Minerals Washington, D. C. American Geophysical Union.CrossRefGoogle Scholar
Środoń, J., Andreoli, C., Elsass, F. and Robert, M. (1990) Direct HRTEM measurement of expandability of mixed-layer illite/smectite in bentonite rock: Clays & Clay Minerals 38, (in press).CrossRefGoogle Scholar
Thompson, J. B. Jr., 1978 Biopyriboles and polysomatic series Amer. Mineral. 63 239 – 249.Google Scholar
Veblen, D. R., 1985 Extended defects and vacancy nonstoichiometry in rock-forming minerals Point Defects in Minerals, Geophysical Monograph 31 122 – 131.Google Scholar
Veblen, D. R., 1985 Direct TEM imaging of complex structures and defects in silicates Annual Review Earth Planetary Sci. 13 119 – 146.CrossRefGoogle Scholar