Quick
Search: 		  
advanced search
 GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help 
European Journal of Mineralogy Don't get GSW? Talk to your librarian.
JOURNAL HOME HELP FEEDBACK/COMMNET SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
European Journal of Mineralogy; October/November; v. 21; no. 5; p. 995-1008; DOI: 10.1127/0935-1221/2009/0021-1954
© 2009 E. Schweizerbart'sche Verlagsbuchhandlung Science Publishers
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Google Scholar
Right arrow Articles by Dainyak, L. G.
Right arrow Articles by Drits, V. A.

Articles

An improved model for the interpretation of Mössbauer spectra of dioctahedral 2:1 trans-vacant Fe-rich micas: refinement of parameters

Lidia G. Dainyak1,*, Viacheslav S. Rusakov2, Ivan A. Sukhorukov2, Bella B. Zviagina1 and Victor A. Drits1

1 Geological Institute of the Russian Academy of Science, Pyjzhevsky Street 7, 119017 Moscow, Russia
2 Department of Physics, Lomonosov Moscow State University, Vorobyovy Gory, 119899 Moscow, Russia

* Corresponding author, e-mail: dainyak{at}ginras.ru; lidia_dainyak{at}yahoo.com

Two Upper Riphean glauconite samples of the Southern Urals with unusually low Fe3+/Fe2+ ratios were studied by 57Fe Mössbauer and IR spectroscopy. Room and liquid-nitrogen temperature Mössbauer spectra were analyzed with quasi-continuous model-independent quadrupole splitting distributions (QSDs). The obtained QSDs were interpreted using a crystal-chemical model taking account of the effects of the local structural and chemical heterogeneity of layer silicates. The main parameters of the crystal-chemical model are individual quadrupole splittings, {Delta}ipred and {Delta}itent, for Fe3+ and Fe2+, respectively, in different local cationic arrangements (LCAs) with their occurrence probabilities, wi, provided by two-dimensional simulation of the cation distribution (CD). Using the parameters of the crystal-chemical model, QSDsim profiles were simulated and compared with the experimental QSDs. To obtain agreement between QSDexp and QSDsim profile, wi and {Delta}i values were adjusted using the method of successive approximations. As a result, the tentative {Delta}itent values for Fe2+ contributions to Mössbauer spectra were refined. The sequence of refined {Delta}iref values corresponding to specific LCA types remained the same as that for the {Delta}itent values. For the studied glauconites, the CD reconstructions satisfying the experimental QSDs are characterized by similar local distribution of cations around Fe3+ and by different local cation distribution around Fe2+.

Key-words: Mössbauer spectroscopy, glauconite, quasi-continuous model-independent QSD, crystal-chemical model.






JOURNAL HOME HELP FEEDBACK/COMMNET SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2009 by E. Schweizerbart'sche Verlagsbuchhandlung Science Publishers