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Mössbauer Spectra of Soil Kaolins from South-Western Australia

Published online by Cambridge University Press:  28 February 2024

Tim G. St. Pierre
Affiliation:
School of Mathematical and Physical Sciences, Murdoch University, Murdoch, Western Australia 6150
Balwant Singh
Affiliation:
Soil Science and Plant Nutrition, School of Agriculture, University of Western Australia, Nedlands, Western Australia 6009
John Webb*
Affiliation:
School of Mathematical and Physical Sciences, Murdoch University, Murdoch, Western Australia 6150
Bob Gilkes
Affiliation:
Soil Science and Plant Nutrition, School of Agriculture, University of Western Australia, Nedlands, Western Australia 6009
*
3Person to whom correspondence should be addressed.
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Abstract

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Six well-characterized soil kaolins from widely separated sites in south-western Australia and four reference kaolins were studied by 57Fe Mössbauer spectroscopy at room temperature after removal of non-structurally-bound iron with dithionite-citrate-bicarbonate solution. The soil kaolins and one of the reference kaolins were also studied at temperatures near 16 K. The soil kaolins were remarkably similar in crystal size, crystallinity, dehydroxylation temperature, cation exchange capacity, surface area and iron content. Müssbauer spectra of the soil kaolins at room temperature were also essentially identical consisting of a quadrupole-split doublet superimposed on a broad component which indicated that all of the iron was present as Fe(III) and that slow paramagnetic relaxation effects were present. Mean values for the chemical isomer shift and quadrupole splitting of the doublet for the soil kaolins were 0.33 and 0.55 mm/s respectively which indicates that the iron is in the octahedral sites of the kaolin lattice. The spectra of the soil kaolin samples at temperatures near 16 K showed a further slowing down of the paramagnetic relaxation and confirmed that no discrete iron oxide minerals were present.

Mössbauer spectra of the four reference kaolins at room temperature showed a doublet component similar to those for the soil kaolins. Three of them showed evidence for other spectral components including, in two cases, a component due to the presence of Fe(II).

Type
Research Article
Copyright
Copyright © 1992, The Clay Minerals Society

References

Bailey, S. W., Brindley, G. W. and Brown, G., 1980 Structures of layer silicates Crystal Structures of Clay Minerals and Their X-ray Identification London Mineralogical Society 1124.Google Scholar
Bolland, M D A Posner, A. M. and Quirk, J. P., 1976 Surface charge on kaolinites in aqueous suspension Austr. J. Soil. Res. 14 197216 10.1071/SR9760197.Google Scholar
Cuttler, A. H., 1980 The behaviour of a synthetic 57Fe-doped kaolin: Mossbauer and electron paramagnetic resonance studies Clay Miner. 15 429444 10.1180/claymin.1980.015.4.10.Google Scholar
Dixon, J. B., Dixon, J. B. and Weed, S. B., 1989 Kaolin and serpentine group minerals Minerals in Soil Environments 2nd ed. Madison, Wisconsin, USA Soil Sci. Soc. Am. Book Series 467525.CrossRefGoogle Scholar
Fysh, S. A., Cashion, J. D. and Clark, P. E., 1983 Mossbauer effect studies of iron in kaolin. I. Structural iron Clays & Clay Minerals 31 285292 10.1346/CCMN.1983.0310406.Google Scholar
Herbillon, A. J., Mestdagh, M. M., Vielvoye, L. and Derouane, E. G., 1976 Iron in kaolinite with special reference to kaolinite from tropical soils Clay Miner. 11 201220 10.1180/claymin.1976.011.3.03.Google Scholar
Hughes, J. C. and Brown, G., 1979 A crystallinity index for soil kaolins and its relation to parent rock, climate and soil maturity J. Soil. Sci. 30 557563 10.1111/j.1365-2389.1979.tb01009.x.Google Scholar
Malden, P. J. and Meads, R. E., 1967 Substitution by iron in kaolinite Nature 215 844846 10.1038/215844b0.CrossRefGoogle Scholar
Mehra, O. P. and Jackson, M. L., 1960 Iron oxide removal from soils and clays by a dithionite-citrate system buffered with sodium bicarbonate Clays & Clay Minerals 7 317327 10.1346/CCMN.1958.0070122.Google Scholar
Mestdagh, M. M., Vielvoye, L. and Herbillon, A. J., 1980 Iron in kaolinite: II. The relationship between kaolinite crystallinity and iron content Clay Miner. 15 113 10.1180/claymin.1980.015.1.01.Google Scholar
Murad, E. and Wagner, U., 1991 Mossbauer spectra of kaolinite, halloysite and the firing products of kaolinite: New results and a reappraisal of published work N. Jahrb. Miner. Abh. 162 281309.Google Scholar
Petit, S. and Decarreau, A., 1990 Hydrothermal (200°C) synthesis and crystal chemistry of iron-rich kaolinites Clay Miner. 25 181196 10.1180/claymin.1990.025.2.04.CrossRefGoogle Scholar
Singh, B., 1991 Mineralogical and chemical characterization of soils from south-western Australia Nedlands, Western Australia University of Western Australia.Google Scholar
Singh, B. and Gilkes, R. J., 1992 Properties of soil kaolins from southwestern Australia J. Soil Sci. .Google Scholar