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Electron spin resonance studies of montmorillonites

Published online by Cambridge University Press:  09 July 2018

C. Crăciun  and
Aurelia Meghea
C. Crăciun
Affiliation:
Institutul de Cercetări pentru Pedologie şi Agrochimie
Aurelia Meghea
Affiliation:
Institutul Politechnic Bucureşti, B-dul Mărăşti 61, 71331 Bucureşti 32, Romania
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Abstract

Sixteen montmorillonites (8 normal and 8 abnormal using DTA dehydroxylation criteria) from the Gurasada bentonite deposits, Romania, were investigated by ESR. The spectra showed two features: a g = 4·3 signal attributed to isolated Fe3+ ions and a broad resonance with g ∼ 2·0 which was interpreted as arising from exchange interactions between clusters of Fe3+ ions. Additional experiments suggested that the latter resonance could have a structural component. The line-shape of the two resonances varied between normal and abnormal montmorillonites, indicating that the distribution of the Fe3+ ions between internal phase (montmorillonite lattice) and external phase (montmorillonite surface) was different for the two varieties.

Type
Research Article
Information
Clay Minerals , Volume 20 , Issue 3 , September 1985 , pp. 281 - 290
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1985

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