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Magnetic properties and site occupancy of iron in nontronite

Published online by Cambridge University Press:  09 July 2018

P. R. Lear  and
J. W. Stucki
P. R. Lear
Affiliation:
University of Illinois, Urbana, IL 61801 USA
J. W. Stucki
Affiliation:
University of Illinois, Urbana, IL 61801 USA
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Abstract

The magnetic susceptibilities of seven different nontronites in their natural oxidation states were measured between 5 and 100 K. Results revealed that the magnetic exchange interaction in all samples was antiferromagnetic, except no clear minimum occurred at the Néel temperature. Possible explanations for this phenomenon which are discussed include magnetic dilution due to isomorphous substitution, and antiferromagnetic frustration due to either non-centrosymmetric distribution of octahedral Fe3+ or tetrahedral Fe3+ substitution. A computer simulation model was developed to demonstrate the effects of these variables on long-range magnetic ordering. Magnetic dilution and tetrahedral Fe3+ content could explain the anomalous antiferromagnetic behaviour in some, but not all, samples. The non-centrosymmetric model is the only one which explains the behaviour of all samples. In this model, at least 13% of the octahedral Fe3+ would occupy trans-dihydroxide sites, with the balance in cis sites. Magnetic frustration occurs because two Fe3+ neighbours of a third Fe3+ ion are also neighbours to each other, making the simultaneous satisfaction of all antiferromagnetic exchange interactions impossible.

Type
Research Article
Information
Clay Minerals , Volume 25 , Issue 1 , March 1990 , pp. 3 - 13
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1990

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References

Ballet, O. & Coey, J.M.D. (1982) Magnetic properties of sheet silicates; 2:1 layer minerals. Phys. Chem. Miner., 8, 218–229.Google Scholar
Besson, G., Brookins, A.S., Daynyak, L.G., Rautaureau, M., Tsipursky, S.I., Tchoubar, C. & Drits, V.A. (1983) Use of diffraction and Mössbauer methods for the structural and crystallochemical characterization of nontronites. J. Appl. Cryst., 16, 374–383.CrossRefGoogle Scholar
Bonnin, D., Calas, G., Suquet, H. & Pezerat, H. (1985) Site occupancy of Fe3+ in Garfield nontronite: a spectroscopic study. Phys. Chem. Miner., 12, 55–64.Google Scholar
Cardile, C.M. (1987) Structural studies of montmorillonites by 57Fe Mössbauer spectroscopy. Clay Miner., 22, 387–394.Google Scholar
Cardile, C. M. (1989) Tetrahedral iron in smectite: A critical comment. Clays Clay Miner., 37, 185–188.Google Scholar
Cardile, C.M. & Johnston, J.H. (1985) Structural studies of nontronites with different iron contents by 57Fe Mössbauer spectroscopy. Clays Clay Miner., 33, 295–300.CrossRefGoogle Scholar
Coey, J.M.D. (1984) Mössbauer spectroscopy of silicate minerals. Pp. 443–509 in: Mössbauer Spectroscopy Applied to Inorganic Chemistry, Vol. 1. (G.J. Long, editor). Plenum, New York.CrossRefGoogle Scholar
Coey, J.M.D. (1988) Magnetic properties of iron in soil iron oxides and clay minerals. Pp. 397–466 in: Iron in Soils and Clay Minerals (J. W. Stucki, B.A. Goodman & U. Schwertmann, editors). D. Reidel, Dordrecht.Google Scholar
Daynyak, L.G. & Drits, V.A. (1987) Interpretation of Mössbauer spectra of nontronite, celadonite, and glauconite. Clays Clay Miner., 35, 363–372.CrossRefGoogle Scholar
Eggleton, R.A. (1977) Nontronite; chemistry and X-ray diffraction. Clay Miner., 12, 181–194.Google Scholar
Goodman, B.A. (1978) The Mössbauer spectra of nontronites: consideration of an alternative assignment. Clays Clay Miner., 26, 176–177.CrossRefGoogle Scholar
Goodman, B.A. (1987) On the use of Mössbauer spectroscopy for determining the distribution of iron in aluminosilicate minerals. Clay Miner., 22, 363–366.Google Scholar
Goodman, B.A., Russell, J.D., Fraser, A.R. & Woodhams, F.W.D. (1976) A Mössbauer and infrared spectroscopic study of the structure of nontronite. Clays Clay Miner., 24, 53–59.Google Scholar
Heller-Kallai, L. & Rozenson, I. (1980) Dehydroxylation of dioctahedral phyllosilicates. Clays Clay Miner., 28, 355–368.Google Scholar
Johnston, J.H. & Cardile, C.M. (1985) Iron sites in nontronite and the effect of interlayer cations from Mössbauer spectra. Clays Clay Miner., 33, 21–30.Google Scholar
Johnston, J.H. & Cardile, C.M. (1987) Iron substitution in montmorillonite, illite, and glauconite by 57Fe Mössbauer spectroscopy. Clays Clay Miner., 35, 170–176.Google Scholar
Lear, P.R. & Stucki, J.W. (1987) Intervalence electron transfer and magnetic exchange interactions in reduced nontronite. Clays Clay Miner., 35, 373–378.Google Scholar
Mering, J. & Oberlin, A. (1967) Electron-optical study of smectites. Clays Clay Miner., 15, 3–25.Google Scholar
Moorjani, K. & Coey, J.M.D. (1984) Magnetic Glasses. Elsevier, Amsterdam.Google Scholar
Murad, E. (1987) Mössbauer spectra of nontronites: Structural implications and characterization of associated iron oxides. Z. Pflanzenernahr. Bodenk., 150, 279–285.Google Scholar
Osthaus, B.B. (1954) Chemical determination of tetrahedral ions in nontronite and montmorillonite. Clays Clay Miner., 2, 404–417.Google Scholar
Russell, J.D. & Clark, D.R. (1978) The effect of Fe for Si substitution on the b-dimension of nontronite. Clay Miner., 13, 133–137.Google Scholar
Sherman, D.M. & Vergo, N. (1988) Optical (diffuse reflectance) and Mössbauer spectroscopic study of nontronite and related Fe-bearing smectites. Am. Miner., 73, 1346–1354.Google Scholar
Stauffer, J. (1979) Scaling theory of percolation clusters. Phys. Rep., 54, 1–74.CrossRefGoogle Scholar
Stucki, J.W. (1988) Structural iron in smectites. Pp. 625-675 in: Iron in Soils and Clay Minerals (J.W. Stucki, B.A. Goodman & U. Schwertmann, editors), D. Reidel, Dordrecht.Google Scholar
Tsipursky, S.I. & Drits, V.A. (1984) The distribution of octahedral cations in the 2:1 layers of dioctahedral smectites studied by oblique-texture electron diffraction. Clay Miner., 19, 177–193.Google Scholar