Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-26T08:45:27.719Z Has data issue: false hasContentIssue false

Impact of clay particle orientation on quantitative clay diffractometry

Published online by Cambridge University Press:  09 July 2018

L. Zevin
Affiliation:
Department of Physico-chemical Geology, Katholieke Universiteit Leuven, Celestijnenlaan 200 C, B-3030 Heverlee, Belgium
W. Viaene
Affiliation:
Department of Physico-chemical Geology, Katholieke Universiteit Leuven, Celestijnenlaan 200 C, B-3030 Heverlee, Belgium

Abstract

Preferred orientation of clay particles in various clay mounts was measured with an X-ray texture diffractometer. Pole distributions are approximately symmetrical about the normal to the sample. Particle orientation is characterized by standard deviations ranging from 7° for thin sedimented layers, to 20° and more for dry-pressed samples, the latter showing less dependence on particle size. The orientation of the reflecting particles may span a considerable angular range affecting the intensities of diffraction peaks observed on contemporary powder diffractometers, even those with moderate axial divergence. A theory based on the diffractometer geometry was developed to calculate the effect of particle orientation. Results are presented as modified Lorentz factors for orientations deduced from experimental observations. In qualitative X-ray diffractometry of clays, preference must be given to preparation techniques which ensure a high degree of preferred orientation and therefore strong enhancement of basal reflections. In quantitative X-ray diffractometry, the main factor is the reproducibility of particle orientation, and suction and dry pressing are promising methods of sample preparation.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1990

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

Alexander, L., Klug, H.P. & Kummer, E. (1948) Statistical factors affecting the intensity of X-rays diffracted by crystalline powders. J. Appl Phys., 19, 742–753.Google Scholar
Azaroff, L. (1968) Elements of X-ray Diffraction,p. 202. McGraw Hill, New York.Google Scholar
Boysen, H. & Adlhart, W. (1987) Resolution correction in diffuse scattering experiments. J. Appl. Cryst., 20, 200–209.CrossRefGoogle Scholar
Brindley, G.W. & Kurtossy, S.S. (1961) Quantitative determination of kaolinite by X-ray diffraction. Am. Miner., 46, 1205–1215.Google Scholar
Decleer, J. (1985) Comparison between mounting techniques for clay minerals as a function of quantitative estimations by X-ray diffraction. Bull. Soc. Belg. Geol., 94, 275–281.Google Scholar
Dollase, W. A. (1986) Correction of intensities for preferred orientation in powder diffractometry: application of the March Model. J. Appl. Cryst., 19, 267–272.CrossRefGoogle Scholar
Gibbs, R.J. (1965) Error due to segregation in quantitative clay mineral X-ray diffraction mounting techniques. Am. Miner., 50, 741–751.Google Scholar
Hawkins, R.K. & Egelstaff, P.A. (1980) Interfacial water structure in montmorilonite from neutron diffraction experiments. Clays Clay Miner., 28, 19–28.CrossRefGoogle Scholar
Kheiker, D.M. & Zevin, L.S. (1963) X-ray diffractometry of coarse-grain samples. Industrial Laboratory, USSR, 29, 168–173.Google Scholar
Klug, H.P. & Alexander, L.E. (1974) X-ray Diffraction Procedures. Wiley, New York.Google Scholar
Lippmann, F. (1970) Functions dsecribing preferred orientation in flat aggregates of flake-like clay minerals and in other axially symmetric fabrics. Contr. Miner. Petrol., 25, 77–94.CrossRefGoogle Scholar
Mildner, D.F.R. & Carpenter, J.M. (1987) Resolution of small-angle scattering with Soller collimation. J. Appl. Cryst., 20, 419424.CrossRefGoogle Scholar
Reynolds, R.C. (1976) The Lorentz factor for basal reflections from micaceous minerals in oriented powder aggregates Am. Miner., 6, 484–491.Google Scholar
Reynolds, R.C. (1986) Lorentz-polarization factor and preferred orientation in oriented clay aggregates. Clays Clay Miner., 34, 359–367.CrossRefGoogle Scholar
Roe, R.J. & Krigbaum, W.R. (1964) Description of crystalline orientation in polycrystalline materials having fiber texture. J. Chem. Phys., 40, 2608–2615.CrossRefGoogle Scholar
Smith, S.T., Snyder, R.L. & Brownell, W.E. (1978) Minimization of preferred orientation in powders by spray drying. Adv, X-ray Anal., 22, 77–87.Google Scholar
Sturm, E. & Lodding, W. (1968) Correction for preferred orientation of platelike particles in diffractometrix powder analysis. Acta Cryst., 24, 650–653.CrossRefGoogle Scholar
Taylor, R.M. & Norrish, K. (1966) The measurement of orientation distribution and its application to quantitative X-ray diffraction analysis. Clay Miner., 6, 127–142.CrossRefGoogle Scholar
Van Olphen, H. & Fripiat, J.J. (editors) (1979) Data Handbook for Clay Materials and other Non-Metallic Minerals. Pergamon Press, New York.Google Scholar
Wilson, A.J.C. (1963) Mathematical Theory of X-ray Powder Diffractometry. Philips Technical Library, Eindhoven.Google Scholar
Wolff de, P.M. (1958) Particle statistics in X-ray diffractometry. Appl. Sci. Res. B7, 102107.CrossRefGoogle Scholar
Zevin, L. (1990) Lorentz factor for oriented samples in powder diffractometry. Acta Cryst. A (in press).CrossRefGoogle Scholar