Hostname: page-component-76fb5796d-5g6vh Total loading time: 0 Render date: 2024-04-28T18:23:47.569Z Has data issue: false hasContentIssue false
  • English
  • Français

Application of Rietveld Refinement Techniques to a Disordered IIb Mg-Chamosite

Published online by Cambridge University Press:  28 February 2024

Jeffrey R. Walker  and
David L. Bish
Jeffrey R. Walker
Affiliation:
Department of Geology and Geography, Vassar College, Poughkeepsie, New York 12601
David L. Bish
Affiliation:
EES-1. Mailstop D469, Los Alamos National Laboratory, Los Alamos, New Mexico 87545
Get access Rights & Permissions [Opens in a new window]

Abstract

The structure of a disordered IIb Mg-chamosite was studied using Rietveld refinement techniques and powder X-ray diffraction (CuKα, 18–120° 2θ in 0.02° 2θ increments). The refinement in space group CĪ yielded high precision lattice parameters (a = 5.36982(5)Å, b = 9.3031(9)Å, c = 14.2610(6)Å, α = 90.315(5)°, β = 97.234(7)°, γ = 90.022(9)°) and atomic coordinates very similar to previous studies. However, the presence of semi-random stacking in this specimen created a situation in which not all atoms could be precisely located: the positions of the octahedral cations and anions which repeat at intervals of ±b/3 could be uniquely determined in three dimensions whereas only the z parameter of the other atoms could be refined. The reasonable appearance of the final model, despite the fact that many of the atom positions could be located in only one dimension, may have resulted because all of the atoms in this structure except O(5) repeat at intervals which are very nearly ±b/3.

Keywords

ChloriteDisorderRietveld refinement
Type
Research Article
Information
Clays and Clay Minerals , Volume 40 , Issue 3 , June 1992 , pp. 319 - 322
Copyright
Copyright © 1992, 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

Adams, J. M., Hydrogen atom positions in kaolinite by neutron profile refinement Clays & Clay Minerals 1983 31 352 – 356 10.1346/CCMN.1983.0310504.Google Scholar
Adams, J. M. and Hewat, A. W., Hydrogen atom positions in dickite Clays & Clay Minerals 1982 29 316 – 356 10.1346/CCMN.1981.0290410.Google Scholar
Bailey, S. W., Brindley, G. W. and Brown, G., Structures of layer silicates Crystal Structures of Clay Minerals and their X-ray Identification 1984 1 – 123.Google Scholar
Bailey, S. W., Practical notes concerning the indexing of X-ray powder diffraction patterns of clay minerals Clays & Clay Minerals 1991 39 184 – 190 10.1346/CCMN.1991.0390210.Google Scholar
Bailey, S. W. and Brown, B. E., Chlorite polytypism. I. Regular and semi-random one-layer structures Amer. Mineral. 1962 47 819 – 850.Google Scholar
Bish, D. L., Rietveld refinement of the dickite structure at 12K Programs and Abstracts 1991 15.Google Scholar
Bish, D. L. and Post, J. E., Refinement of the sepiolite structure and location of tunnel water molecules using the Rietveld method Programs and Abstracts 1987 33.Google Scholar
Bish, D. L. and Von Dreele, R. B., Rietveld refinement of non-hydrogen atomic positions in kaolinite Clays & Clay Minerals 1989 37 289 – 296 10.1346/CCMN.1989.0370401.Google Scholar
Bish, D. L. and Von Dreele, R. B., The crystal structure of kaolinite including hydrogen atoms Programs and Abstracts 1990 25.Google Scholar
Joswig, W. and Fuess, H., Refinement of a one-layer triclinic chlorite Clays & Clay Minerals 1990 38 216 – 218 10.1346/CCMN.1990.0380215.Google Scholar
Larson, A. C. and Von Dreele, R. B., GSAS Generalized Structure Analysis System. 1990 Los Alamos, New Mexico Los Alamos National Laboratory.Google Scholar
Martin, R. T., Bailey, S. W., Eberl, D. D., Fanning, D. S., Guggenheim, S., Kodama, H., Pevear, D. R., Srodon, J. and Wicks, F. J., Report of the Clay Minerals Society Nomenclature Committee: Revised classification of clay minerals Clays & Clay Minerals 1991 39 333 – 335 10.1346/CCMN.1991.0390315.CrossRefGoogle Scholar
Post, J. E., Bish, D. L., Bish, D. L. and Post, J. E., Rietveld refinement of crystal structures using powder X-ray diffraction data Modern Powder Diffraction 1989 Washington D.C. Mineralogical Society of America 277 – 308 10.1515/9781501509018-012.Google Scholar
Rakovan, J. and Guggenheim, S., Rietveld refinement of a I lb clinochlore Programs and Abstracts 1991 132.Google Scholar
Rietveld, H. M., Line profiles of neutron powderdiffraction peaks for structure refinement Acta Cryst. 1967 22 151 – 152 10.1107/S0365110X67000234.CrossRefGoogle Scholar
Rietveld, H. M., A profile refinement method for nuclear and magnetic structures J. Appl. Crystallog. 1969 2 65 – 71 10.1107/S0021889869006558.Google Scholar
Suitch, P. R. and Young, R. A., Atom positions in highly ordered kaolinite Clays & Clay Minerals 1983 31 357 – 366 10.1346/CCMN.1983.0310505.Google Scholar
Toraya, H., Iwai, S. and Marumo, F., The structural investigation of a kaolinite mineral by X-ray powder pattern-fitting Mineral. J. (Japan) 1980 10 168 – 180 10.2465/minerj.10.168.Google Scholar
Young, R. A. and Hewat, A. W., Verification of the triclinic crystal structure of kaolinite Clays and Clay Minerals 1988 36 225 – 232 10.1346/CCMN.1988.0360303.Google Scholar
Walker, J. R. and Bish, D. L., Rietveld refinement of IIb chlorite Programs and Abstracts 1989 73.Google Scholar
Walker, J. R., Bish, D. L. and Veblen, D. R., Comparison of coherent diffracting domain size as estimated from powder X-ray diffraction data and as measured in TEM images Programs and Abstracts 1990 125.Google Scholar