Hostname: page-component-848d4c4894-r5zm4 Total loading time: 0 Render date: 2024-06-26T04:56:09.416Z Has data issue: false hasContentIssue false
  • English
  • Français

Consistent Modeling of the XRD Patterns of Mixed-Layer Phyllosilicates

Published online by Cambridge University Press:  01 January 2024

Alain Plançon
Alain Plançon*
Affiliation:
Institut des Sciences de la Terre d’Orléans, CNRS, 45071 Orléans Cedex 2, France
*
*E-mail address of corresponding author: Alain.Plancon@univ-orleans.fr
Get access Rights & Permissions [Opens in a new window]

Abstract

The Markovian model of mixed-layering that has been used until now for the modeling of X-ray diffraction (XRD) patterns of 2:1 phyllosilicates describes the mixed-layer crystals as stacks of ‘layer units’ (LUs) that associate a 2:1 layer with an interlayer content. This model is not consistent when it is applied to a mixed-layer mineral (MLM) involving electrically charged layers, i.e. most of the mixed-layer phyllosilicates with 2:1 layers. Two consistent models can be proposed for these MLMs, which, instead of LUs, stack ‘interlayer units’ (IUs), composed of an interlayer content sandwiched between two half-layers. The IU-NPL model (interlayer units, non-polar layers) imposes non-polarity on the 2:1 layers resulting from the stack of these IUs, which implies restrictions on the succession of the IUs. In the other consistent model, the IU-PL one (interlayer units, polar layers), these restrictions are not imposed. These two models reproduce the Non-Polar 2:1 Layer Model and the Polar 2:1 Layer Model described by Altaner and Ylagan for illite-smectite mixed layering, and the second model corresponds to the stacks of O0.5 T I′ T O0.5 units described by Olives et al.

The present work points out the similarities and discrepancies of the calculated XRD patterns by using computer programs designed for the three models of mixed-layering (LU, IU-NPL and IU-PL) and for two-and three-component MLMs. Illustrations are provided for some I-S and I-S-V MLMs.

The IU-PL model leads to XRD patterns similar to those of the LU model. It is in agreement with lattice-energy calculations, expandability measurement, HRTEM imaging and NMR spectroscopy.

Keywords

2:1 LayerIllite-smectiteInterlayer UnitLayer UnitMixed LayerStructural DeterminationXRD Pattern
Type
Research Article
Information
Clays and Clay Minerals , Volume 52 , Issue 1 , February 2004 , pp. 47 - 54
Copyright
Copyright © 2004, The Clay Minerals Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Altaner, S.P. and Ylagan, R.F., (1997) Comparison of structural models of mixed-layer illite/smectite and reaction mechanisms of smectite illitization Clays and Clay Minerals 45 517–533 10.1346/CCMN.1997.0450404.CrossRefGoogle Scholar
Altaner, S.P. Weiss, C.A. and Kirkpatrick, R.J., (1988) Evidence from 29Si NMR for the structure of mixed-layer illite/smectite clay minerals Nature 331 699–702 10.1038/331699a0.CrossRefGoogle Scholar
Barron, P.F. Slade, P. and Frost, R.L., (1985) Ordering of aluminium in tetrahedral sites in mixed-layer 2:1 phyllosilicates by solid-state high-resolution NMR Journal of Physical Chemistry 89 3880–3885 10.1021/j100264a023.CrossRefGoogle Scholar
Drits, V.A. and Sakharov, B.A., (1976) X-ray Structure Analysis of Interstratified Minerals Moskow Nauka 225 pp. (in Russian).Google Scholar
Drits, V.A. Sakharov, B.A. and Lindgreen, H., (1997) Sequential structure transformation of illite-smectite-vermiculite during diagenesis of Upper Jurassic shales from the North Sea and Denmark Clay Minerals 32 351–371 10.1180/claymin.1997.032.3.03.CrossRefGoogle Scholar
Jakobsen, H.J. Nielsen, N.C. and Lindgreen, H., (1995) Sequences of charged sheets in rectorite American Mineralogist 80 247–252 10.2138/am-1995-3-406.CrossRefGoogle Scholar
Jiang, W.T. Peacor, D.R. Merriman, R.J. and Roberts, B., (1990) Transmission and analytical electron microscopic study of mixed-layer illite/smectite formed as an apparent replacement product of diagenetic illite Clays and Clay Minerals 38 449–468 10.1346/CCMN.1990.0380501.CrossRefGoogle Scholar
Kakinoki, J. and Komura, Y., (1965) Diffraction by one-dimensionally disordered crystals. I: the intensity equation Acta Crystallographica 19 137–147 10.1107/S0365110X65002888.CrossRefGoogle Scholar
Moore, D.M. and Reynolds, R.C., (1989) X-ray Diffraction and the Identification and Analysis of Clay Minerals Oxford, UK Oxford University Press 311–325 Appendix.Google Scholar
Olives, J. Amouric, M. and Perbost, R., (2000) Mixed layering of illite-smectite: results from high-resolution transmission electron microscopy and lattice-energy calculations Clays and Clay Minerals 48 282–289 10.1346/CCMN.2000.0480215.CrossRefGoogle Scholar
Plançon, A., (2002) New modeling of X-ray diffraction by disordered lamellar structures, such as phyllosilicates American Mineralogist 87 1672–1677 10.2138/am-2002-11-1216.CrossRefGoogle Scholar
Plancon, A., (2003) Modelling X-ray diffraction by lamellar structures composed of electrically charged layers Journal of Applied Crystallography 36 146–153 10.1107/S0021889802019362.CrossRefGoogle Scholar
Plançon, A. and Drits, V.A., (2000) Phase analysis of clays using an expert system and calculation programs for X-ray diffraction by two- and three-component mixed-layer minerals Clays and Clay Minerals 48 57–62 10.1346/CCMN.2000.0480107.CrossRefGoogle Scholar
Reynolds, R.C., (1967) Interstratified clay systems: calculation of total one-dimensional diffraction functions American Mineralogist 52 661–672.Google Scholar
Reynolds, R.C., (1985) NEWMOD: a computer program for the calculation of one-dimensional diffraction patterns of mixed-layer clays 9 Brook Rd., New Hampshire 03755, USA R.C. Reynolds.Google Scholar
Sakharov, B.A. Lindgreen, H. Salyn, A. and Drits, V.A., (1999) Determination of illite-smectite structures using multispecimen X-ray diffraction profile fitting Clays and Clay Minerals 47 555–566 10.1346/CCMN.1999.0470502.CrossRefGoogle Scholar
Sakharov, B.A. Plançon, A. and Drits, V.A., (1999) Influence of outer surface structure of crystals on X-ray diffraction Euroclay 1999 abstracts volume 129.Google Scholar
Sudo, T. Hayashi, H. Shimoda, S. and Swineford, A., (1962) Mineralogical problems of intermediate clay minerals Proceedings of the 9th National Conference on Clays and Clay Minerals, Lafayette, Indiana, 1960 New York Pergamon Press 378–388.Google Scholar
Veblen, D.R. Guthrie, G.D. Livi, K.J.T. and Reynolds, R.C., (1990) High resolution transmission electron microscopy and electron diffraction of mixed-layer illite/smectite: Experimental results Clays and Clay Minerals 38 1–13 10.1346/CCMN.1990.0380101.CrossRefGoogle Scholar