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Structural Study of a Benzidine-Vermiculite Intercalate Having a High Tetrahedral-Iron Content by 57Fe Mössbauer Spectroscopy

Published online by Cambridge University Press:  02 April 2024

C. M. Cardile*
Affiliation:
Chemistry Department, Victoria University of Wellington, Private Bag, Wellington, New Zealand
P. G. Slade
Affiliation:
CSIRO Division of Soils, Private Bag No. 2, Glen Osmond, South Australia 5064, Australia
*
3Present address: DSIR Chemistry Division, Private Bag, Petone, New Zealand.
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Abstract

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57Fe Mössbauer spectra obtained at room temperature and 78 K for natural Mg-saturated, Ca-saturated, and benzidinium-intercalated vermiculite having a high tetrahedral iron content are presented. For all samples the spectra were computer-fitted with five overlapping doublets, representing Fe in both tetrahedral and octahedral sites. One doublet has parameters consistent with the weathered ilmenite known to be present as inclusions. For the intercalated vermiculite, the δ value of the doublet assigned to the tetrahedral Fe3+ increased with respect to the untreated sample, suggesting that the electron densities about the Fe sites had decreased following intercalation. A charge movement from the silicate layers towards the interlayer monovalent benzidinium ions is also implied. The direction of this charge movement is opposite to that found when blue monopositive radical cations form on montmorillonite surfaces. The Mössbauer evidence suggests the absence of an interlayer-Fe3+ complex.

Type
Research Article
Copyright
Copyright © 1987, The Clay Minerals Society

References

Annersten, H. and Olesch, M., 1978 Distribution of ferrous and ferric iron in clintonite and the Mössbauer characteristics of ferric iron in tetrahedral co-ordination Can. Mineral. 16 199203.Google Scholar
Cardile, C. M. and Johnston, J. H., 1985 Structural studies of nontronites with different iron contents by 57Fe Mössbauer spectroscopy Clays & Clay Minerals 33 295300.CrossRefGoogle Scholar
Cardile, C. M. and Johnston, J. H., 1986 A 57Fe Mössbauer spectroscopic study of montmorillonites: A new interpretation Clays & Clay Minerals 34 307313.CrossRefGoogle Scholar
Coey, J. M. D., 1980 Clay minerals and their transformations studied with nuclear techniques: The contribution of Mössbauer spectroscopy At. Energy Rev. 18 73124.Google Scholar
Ericsson, T., Linares, J. and Lotse, E., 1984 A Mössbauer study of dithionite/citrate/bicarbonate treatment on a Vermiculite, a smectite and a soil Clay Miner. 19 8591.CrossRefGoogle Scholar
Ericsson, T., Wäppling, R. and Punakivi, K., 1977 Mössbauer spectroscopy applied to clay and related minerals Geol. Fören. Förhandl. 99 229244.CrossRefGoogle Scholar
Gibb, T. C., Greenwood, N. N. and Twist, W., 1969 The Mössbauer spectra of natural ilmenites J. Inorg. Nucl. Chem. 31 947954.CrossRefGoogle Scholar
Goodman, B. A. and Wilson, M. J., 1973 A study of the weathering of a biotite using the Mössbauer effect Mineral. Mag. 39 448454.CrossRefGoogle Scholar
Heller-Kallai, L. and Rozenson, I., 1981 The use of Mössbauer spectroscopy of iron in clay mineralogy Phys. Chem. Minerals 7 223238.CrossRefGoogle Scholar
Johnston, J. H. and Cardile, C. M., 1985 Iron sites in nontronite and the effect of interlayer cations from Mössbauer spectra Clays & Clay Minerals 33 2130.CrossRefGoogle Scholar
Johnston, J. H. and Cardile, C. M., 1987 Iron substitution in montmorillonite, illite, and glauconite by 57Fe Mössbauer spectroscopy Clays & Clay Minerals 35 170176.CrossRefGoogle Scholar
Johnston, J. H., Lewis, D. G., Long, G. J. and Stephens, J. G., 1986 A study of the initially formed hydrolysis species and intermediate polymers and their role in determining the product iron oxides formed in the weathering of iron Proc. Conf. on Industrial Applications of the Mössbauer Effect, Honolulu, Hawaii, 1984 New York Plenum Publishing Co..Google Scholar
Norrish, K. and Serratoza, J. M., 1973 Factors in the weathering of mica to vermiculite Proc. Int. Clay Conf, Madrid, 1972 Madrid Div. Ciencias, C.S.I.C. 417432.Google Scholar
Rozenson, I. and Heller-Kallai, L., 1977 Mössbauer spectra of dioctahedral smectites Clays & Clay Minerals 25 94101.CrossRefGoogle Scholar
Slade, P. G. and Raupach, M., 1982 Structural model for benzidine-vermiculite Clays & Clay Minerals 30 297305.CrossRefGoogle Scholar
Taylor, G. L., Ruotsala, A. P. and Keeling, R. O., 1968 Analysis of iron in layer silicates by Mössbauer spectroscopy Clays & Clay Minerals 16 381391.CrossRefGoogle Scholar
Tennakoon, D. T. P. Thomas, J. M. and Tricker, M. J., 1974 Surface and intercalate chemistry of layered silicates. Pt. II. An iron-57 Mössbauer study of the role of lattice-substituted iron in the benzidine blue reaction of montmorillonite J. Chem. Soc. Dalton Trans. 20 22112215.CrossRefGoogle Scholar
Tsipursky, S. I. and 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 177193.CrossRefGoogle Scholar