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Application of the Rietveld Method in the Reynolds Cup Contest

Published online by Cambridge University Press:  01 January 2024

Kristian Ufer  and
Mark D. Raven
Kristian Ufer*
Affiliation:
Federal Institute for Geosciences and Natural Resources, Hannover, Germany
Mark D. Raven
Affiliation:
CSIRO Land and Water, Urrbrae, Australia
*
*E-mail address of corresponding author: [email protected]
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Abstract

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The Reynolds Cup (RC) is a unique round-robin competition that was established by The Clay Minerals Society in 2000 to assess the level of precision and accuracy that is attainable for the mineralogical analysis of a wide range of complex clay-rich materials. Although the Reynolds Cup roundrobin allows any possible analysis methods, X-ray diffraction (XRD) is by far the most frequently used technique. It is not only used to identify components, but also for quantitative phase analysis (QPA). QPA means determination of the relative concentrations of the coexisting phases in a mixture, commonly as a weight percent (wt.%) or mass fraction. Several approaches allow a quantitative determination of mineral contents, such as the Rietveld method (Rietveld, 1967). The successful application of the Rietveld method for QPA requires that all components are correctly identified and that the component diffraction patterns are appropriately described, which is preferably based on structure. In addition, the quality of a Rietveld quantification also depends on suitable sample preparation and measurement conditions, as well as a correct description of instrument configurations. Results from all previous Reynolds Cup contests show that a successful quantification depends strongly on the skill of users. Although the refinement procedure itself is automatic and, therefore, user independent, the results are strongly influenced by the structural models and refinable parameters that are selected and on the limitations of those parameters. Selected examples for the successful application of Rietveld refinement as well as the limitations of the method will be discussed in this article. The goal of the present work was to demonstrate that the Rietveld method is in principle capable of quantifying all Reynolds Cup samples with a high degree of accuracy, but sample specific difficulties and analysts’ inexperience may impede successful application. Incorrect results are often not indicated simply by low residuals or good fits. All refinement results should be validated and corrected using supplementary techniques, even if the results appear acceptable.

Keywords

Quantitative Phase AnalysisReynolds CupRietveld Refinement
Type
Article
Information
Clays and Clay Minerals , Volume 65 , Issue 4 , August 2017 , pp. 286 - 297
Copyright
Copyright © Clay Minerals Society 2017

References

Bergmann, J. Friedel, P. and Kleeberg, R., 1998 BGMN - a new fundamental parameter based Rietveld program for laboratory X-ray sources, its use in quantitative analysis and structure investigations CPD Newsletter, Commission of Powder Diffraction, International Union of Crystallography 20 5–8.Google Scholar
Bergmann, J. and Kleeberg, R., 1998 Rietveld analysis of disordered layer silicates Materials Science Forum 278-281 300–305.CrossRefGoogle Scholar
Bruker AXS, 2009 Topas V4.2 General Profile and Structure Analysis Software for Powder Diffraction Data Karlsruhe, Germany Bruker AXS.Google Scholar
Bish, D.L. and Howard, S.A., 1988 Quantitative phase analysis using the Rietveld method Journal of Applied Crystallography 21 86–91.CrossRefGoogle Scholar
Guthrie, G.D. Jr. Bish, D.L. Reynolds, R.C. Jr., 1995 Modeling the X-ray diffraction pattern of opal-CT American Mineralogist 80 969–872.CrossRefGoogle Scholar
Hill, R.J. and Howard, C.J., 1987 Quantitative phase analysis from neutron powder diffraction data using the Rietveld method Journal of Applied Crystallography 20 467–474.CrossRefGoogle Scholar
Madsen, I.C. Scarlett, N.V.Y. and Kern, A., 2011 Description and survey of methodologies for the determination of amorphous content via X-ray powder diffraction Zeitschrift für Kristallographie 226 944–955.CrossRefGoogle Scholar
Moore, D.M. Reynolds, R.C. Jr., 1997 X-ray Diffraction and the Identification and Analysis of Clay Minerals Oxford Oxford University Press.Google Scholar
Raven, M.D. and Self, P.G., 2011.Secrets to winning the 5th Reynolds Cup competition Abstracts: 48th Annual Meeting of The Clay Minerals SocietyGoogle Scholar
Raven, M.D. and Self, P.G., 2017 Outcomes of 12 years of the Reynolds Cup quantitative mineral analysis round robin Clays and Clay Minerals 65 122–134.CrossRefGoogle Scholar
Rietveld, H.M., 1967 Line profiles of neutron powder-diffraction peaks for structure refinement Acta Crystallografica 22 151–152.CrossRefGoogle Scholar
Scarlett, N.V.Y. and Madsen, I.C., 2006 Quantification of phases with partial or no known crystal structures Powder Diffraction 21 278–284.CrossRefGoogle Scholar
Taylor, J.C., 1991 Computer programs for standardless quantitative analysis of minerals using the full powder diffraction profile Powder Diffraction 6 2–9.CrossRefGoogle Scholar
Taylor, J.C. and Matulis, C.E., 1994 A new method for Rietveld clay analysis: Part 1 Use of a universally measured standard profile for Rietveld quantification of montmorillonites. Powder Diffraction 9 119–123.Google Scholar
Treacy, M.M. Newsam, J.M. and Deem, M.W., 1991 A general recursion method for calculating diffracted intensities from crystals containing planar faults Proceedings of the Royal Society of London A433 499–520.Google Scholar
Ufer, K. Kleeberg, R. Bergmann, J. Curtius, H. and Dohrmann, R., 2008 Refining real structure parameters of disordered layer structures within the Rietveld method Zeitschrift für Kristallographie Suppl. 27 151–158.CrossRefGoogle Scholar
Ufer, K. Kleeberg, R. Bergmann, J. and Dohrmann, R., 2012 Rietveld refinement of disordered illite-smectite mixed layered structures by a recursive algorithm. Part II: Powder-pattern refinement and quantitative phase analysis Clays and Clay Minerals 60 535–552.CrossRefGoogle Scholar
Ufer, K. Roth, G. Kleeberg, R. Stanjek, H. and Dohrmann, R., 2004 Description of X-ray powder pattern of turbostratically disordered layer structures with a Rietveld compatible approach Zeitschrift fur Kristallographie 219 519–527.Google Scholar
Viani, A. Gualtieri, A.F. and Artioli, G., 2002 The nature of disorder in montmorillonite by simulation of X-ray powder patterns American Mineralogist 87 966–975.CrossRefGoogle Scholar
Westphal, T. Füllmann, T. and Pöllmann, H., 2009 Rietveld quantification of amorphous portions with an internal standard - Mathematical consequences of the experimental approach Powder Diffraction 24 239–243.CrossRefGoogle Scholar
Young, R.A., 1993 Introduction to the Rietveld method The Rietveld Method Oxford, UK Oxford University Press 1–38.CrossRefGoogle Scholar