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The determination of layer charge by curve-fitting of Lorentz- and polarization-corrected X-ray diagrams

Published online by Cambridge University Press:  09 July 2018

H. Stanjek
Affiliation:
Lehrstuhl für Bodenkunde, Technische Universität München, 8050 Freising-Weihenstephan, Federal Republic of Germany
R. Friedrich
Affiliation:
Lehrstuhl für Bodenkunde, Technische Universität München, 8050 Freising-Weihenstephan, Federal Republic of Germany

Abstract

The clay fraction from the B horizon of a Psammentic Hapludalf containing vermiculite and smectite was treated with n-alkylammonium chloride ranging from nc = 6 to nc = 16. X-ray data were obtained by step-scanning, stored in a computer, corrected with the Lorentz and polarization factors and then fitted with a deconvolution programme. The layer charge was determined from the uncorrected, the corrected and the fitted diagrams, respectively. The evaluated confidence limits of ξ decreased in the same order revealing the vermiculite to be a high-charge type. The computed charge distribution of the smectite changed from an unlikely bimodal to a nearly symmetrical distribution.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1986

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References

AIPEA Nomenclature Committee (1980) Clays Clay Miner. 28, 7378.Google Scholar
Brindley, G.W. (1981) Long-spacing organics for calibrating long spacings of interstratified clay minerals. Clays Clay Miner. 29, 6768.Google Scholar
Janik, L.M. & Raupach, M. (1977) An iterative, least-squares program to separate infrared absorption spectra into their component bands. CSIR 0 Div. of Soils Tech. Paper 35, 137.Google Scholar
Klug, H.P. & Alexander, L.E. (1973) X-Ray Diffraction Procedures for Polycrystalline and Amorphous Materials. J. Wiley & Sons, New York, 966 pp.Google Scholar
Lagaly, G. (1979) The “Layer Charge” of regular interstratified 2:1 clay minerals. Clays Clay Miner. 27, 110.Google Scholar
Lagaly, G., Fernandez-Gonzalez, M. & Weiss, A. (1976) Problems in layer charge determination of montmorillonites. Clay Miner. 11, 173187.Google Scholar
Lagaly, G. & Weiss, A. (1969) Determination of layer charge in mica-type layer silicates. Proc. Int. Clay Conf., Tokyo, 1, 6168.Google Scholar
Lagaly, G. & Weiss, A. (1976) The layer charge of smectitic layer silicates. Proc. Int. Clay Conf. Mexico, 157172.Google Scholar
Mehra, O.P. & Jackson, M.L. (1960) Iron oxide removal from soils and sediments by a dithionite-citrate system buffered with sodium bicarbonate. Clays Clay Miner. 7, 317327.Google Scholar
Reynolds, R.C. Jr. (1976) The Lorentz factor for basal reflections from micaceous minerals in oriented powder aggregates. Am. Miner. 61, 484491.Google Scholar
Rühlicke, G. & Niederbudde, E.A. (1985) Determination of layer-charge density of expandable 2:1 clay minerals in soils and Loess sediments using the alkylammonium method. Clay Miner. 20, 291300.Google Scholar
Savitzky, A. & Golay, M.J.E. (1964) Smoothing and differentiation of data by simplified least squares procedures. Anal. Chem. 36, 16271639.Google Scholar
Savitzky, A. & Golay, M.J.E. (1972) Comments on smoothing and differentiation of data by simplified least square procedure. Anal. Chem. 44, 19061909.Google Scholar
Schulze, D.G. (1982) The identification of iron oxides by differential X-ray diffraction and the influence of aluminum substitution on the structure of goethite. PhD thesis, Technische Universitäit München, FRG.Google Scholar
Stul, M.S. & Mortier, W.J. (1974) The heterogeneity of the charge density in montmorillonites. Clays Clay Miner. 22, 391396.CrossRefGoogle Scholar
Van Der Gaast, S.J. & Vaars, A.J. (1981) A method to eliminate the background in X-ray diffraction patterns of oriented clay mineral samples. Clay Miner. 16, 383393.Google Scholar