Hostname: page-component-cd9895bd7-lnqnp Total loading time: 0 Render date: 2024-12-27T06:53:56.705Z Has data issue: false hasContentIssue false
  • English
  • Français

X-Ray Powder Diffraction Rietveld Characterization of Synthetic Aluminum-Substituted Goethite

Published online by Cambridge University Press:  02 April 2024

P. G. Fazey ,
B. H. O'Connor  and
L. C. Hammond
P. G. Fazey*
Affiliation:
Department of Applied Physics, Curtin University of Technology, Bentley, Western Australia 6102, Australia
B. H. O'Connor*
Affiliation:
Department of Applied Physics, Curtin University of Technology, Bentley, Western Australia 6102, Australia
L. C. Hammond*
Affiliation:
Department of Applied Physics, Curtin University of Technology, Bentley, Western Australia 6102, Australia
*
1Present address: CSIRO Division of Soils, Private Bag, P.O. Glen Osmond, South Australia 5064, Australia
2To whom all correspondence should be addressed.
3Present address: Materials Research Laboratory, DSTO, P.O. Box 50, Ascot Vale, Victoria 3052, Australia
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Riet veld X-ray powder diffraction (XRD) analysis has been evaluated as a procedure for characterizing Al-substituted goethite according to the Rietveld scale factor, unit-cell parameters, and atom positional parameters. The study was conducted with three synthetic goethite samples for which the degree of Al substitution for Fe determined by chemical analysis was 8.0 ± 0.4, 12.0 ± 0.4, and 20.1 ± 0.4 mole %. The weight fractions of crystalline material (WFCM) in the specimens, determined from the Rietveld scale factors after correcting for adsorbed water and impurities, were 0.878 (esd = 0.014), 0.919 (0.014), and 0.965 (0.015), respectively. The Al mole % substitutions, inferred from the Rietveld cell parameters according to the method of Schulze (1984), were 10.4 ± 2.5, 16.5 ± 2.6, and 17.1 ± 2.6, respectively. The cause of the significant difference between the second value and the chemical analysis result is not known. The atom positional parameters did not differ significantly within the sample suite and agreed satisfactorily with literature values. The results have demonstrated the value of using Rietveld XRD analysis to determine simultaneously the WFCM and Al mole % substitutions, as well as to confirm the non-hydrogen atom positions.

Keywords

AluminumCrystallinityGoethiteRietveld refinementX-ray powder diffraction
Type
Research Article
Information
Clays and Clay Minerals , Volume 39 , Issue 3 , June 1991 , pp. 248 - 253
Copyright
Copyright © 1991, The Clay Minerals Society

References

Bish, D. L. and Howard, S. A., 1988 Quantitative phase analysis using the Rietveld method J. Appl. Crystallogr 21 86 – 91.CrossRefGoogle Scholar
Busing, W. R. and Levy, H.A., 1958 A single crystal neuron diffraction study of diaspore, AlO(OH) Acta Crystallogr 11 798 – 803.CrossRefGoogle Scholar
Cambier, P., 1986 Infrared study of goethites of varying crystallinity and particle size: II. Crystallographic and morphological changes in series of synthetic goethites Clay Miner 21 201 – 210.CrossRefGoogle Scholar
Cornell, R. M., Mann, S. and Skarnulis, A. J., 1983 A high resolution electron microscopy examination of domain boundaries in crystals of synthetic goethite J. Chem. Soc. Faraday Trans. 1 79 2679 – 2684.CrossRefGoogle Scholar
Dollase, W. A., 1986 Correction of intensities for preferred orientation in powder diffractometry: Application of the March model J. Appl. Crystallogr 19 267 – 272.CrossRefGoogle Scholar
Forsyth, J. B., Hedley, I. G. and Johnson, C. E., 1968 The magnetic structure and hyperfine field of goethite (α-Fe-OOH) Proc. Phys. Soc. London, sect. C 1 179 – 188.Google Scholar
Golden, D. C., 1978 Physical and chemical properties of aluminum-substituted goethite .Google Scholar
Hill, R. J., 1979 Crystal structure refinement and electron density distribution in diaspore Phys. Chem. Minerals 5 179 – 200.CrossRefGoogle Scholar
Hill, R. J. and Howard, C. J., 1986 A computer program for Rietveld analysis of fixed wavelength X-ray and neutron powder diffraction patterns: Version LHPM1 New South Wales, Australia Australian Atomic Energy Commission Research Establishment, Lucas Heights.Google Scholar
Hill, R. J. and Howard, C. J., 1987 Quantitative phase analysis from neutron powder diffraction data using the Rietveld method J. Appl. Crystallogr 20 467 – 474.CrossRefGoogle Scholar
Hubbell, J. H., McMaster, W. H., Del Grande, N. K. and Mallett, J. H., 1974 International Tables for X-ray Crystallography (1974), Vol. IV Birmingham, United Kingdom Kynoch Press 47 – 70.Google Scholar
Jordan, B., O’Connor, B. H. and Li, Dey, 1990 Use of Rietveld pattern-fitting to determine the weight fraction of crystalline material in natural low-quartz specimens Powder Diffraction 5 64 – 69.CrossRefGoogle Scholar
Klug, A. and Farkas, L., 1981 Structural investigations of polycrystalline diaspore samples by X-ray powder diffraction Phys. Chem. Minerals 7 138 – 140.CrossRefGoogle Scholar
March, A., 1932 Mathematische Theorie der Regelung nach der Korngestalt bei affiner Deformation Zeit. Kristallogr 81 285 – 297.CrossRefGoogle Scholar
Megaw, H. D., 1973 Crystal Structures—A Working Approach Philadelphia W. B. Sanders Co. 356 – 359.Google Scholar
O’Connor, B. H. and Raven, M. D., 1988 Application of the Rietveld refinement procedure in assaying powdered mixtures Powder Diffraction 3 2 – 6.CrossRefGoogle Scholar
Reynolds, R. C., 1968 Effect of particle size on apparent lattice spacings Acta Crystallogr A24 319 – 320.CrossRefGoogle Scholar
Reitveld, H. M., 1969 A profile refinement method for nuclear and magnetic structures J. Appl. Crystallogr 2 65 – 71.CrossRefGoogle Scholar
Schulze, D. G., 1984 The influence of aluminum on iron oxides, VIII. Unit-cell dimensions of Al-substituted goethites and estimation of Al from them Clays & Clay Minerals 32 36 – 44.CrossRefGoogle Scholar
Schulze, D. G. and Schwertmann, U., 1987 The influence of aluminum on iron oxides: XIII. Properties of goethites synthesised in 0.3 M KOH at 25° Clay Miner 22 83 – 92.CrossRefGoogle Scholar
Shannon, R. D. and Prewitt, C. T., 1969 Effective ionic radii in oxides and fluorides Acta Crystallogr B25 925 – 946.CrossRefGoogle Scholar
Trunz, V., 1976 Influence of crystallite size on the apparent basal spacings of kaolinite Clays & Clay Minerals 24 84 – 87.CrossRefGoogle Scholar
Wiles, D. B. and Young, R. A., 1981 A new computer program for Rietveld analysis of X-ray powder diffraction patterns J. Appl. Crystallogr 14 149 – 151.CrossRefGoogle Scholar