Fe-57 Mossbauer effect study of bannisterite: a modulated 2 : 1-type phyllosilicate
(2006) In Mineralogical Magazine 70(2). p.187-199- Abstract
- Bannisterite is a modulated 2:1-type phyllosilicate having ten octahedral sites with hydroxyl groups in trans, cis and combined trans-cis configurations. Each octahedral site, depending on its proximity to the layer modulation, is exposed to a different degree of distortion. The electric field gradient at the Fe site and the site distortion are used to propose a model for the site assignment and oxidation mechanism in bannisterite. The results show that two models are compatible with the experimental results of fitting the spectrum of bannisterite. However, the model which allows for site distortion accounts better for the observed line overlap of the Fe-[6](2+) sites. Accordingly, the octahedral sites with a greater degree of distortion... (More)
- Bannisterite is a modulated 2:1-type phyllosilicate having ten octahedral sites with hydroxyl groups in trans, cis and combined trans-cis configurations. Each octahedral site, depending on its proximity to the layer modulation, is exposed to a different degree of distortion. The electric field gradient at the Fe site and the site distortion are used to propose a model for the site assignment and oxidation mechanism in bannisterite. The results show that two models are compatible with the experimental results of fitting the spectrum of bannisterite. However, the model which allows for site distortion accounts better for the observed line overlap of the Fe-[6](2+) sites. Accordingly, the octahedral sites with a greater degree of distortion are assigned to the Fe-[6](2+) with lower electric quadrupole splitting, and the octahedral sites with lower site distortion are assigned to the Fe-[6](2+) with higher electric quadrupole splitting. Moreover, the ease of oxidation decreases in the order trans > trans-cis > cis. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/406764
- author
- Ferrow, Embaie LU
- organization
- publishing date
- 2006
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- electric field gradient, distortion, bannisterite, Mossbauer, assignment, site
- in
- Mineralogical Magazine
- volume
- 70
- issue
- 2
- pages
- 187 - 199
- publisher
- Mineralogical Society of Great Britain and Ireland
- external identifiers
-
- wos:000238074400004
- scopus:33745065819
- ISSN
- 0026-461X
- DOI
- 10.1180/0026461067020323
- language
- English
- LU publication?
- yes
- id
- 973aeab3-3a9b-4a92-a720-15640662b2ec (old id 406764)
- date added to LUP
- 2016-04-01 11:49:01
- date last changed
- 2022-01-26 18:41:16
@article{973aeab3-3a9b-4a92-a720-15640662b2ec,
abstract = {{Bannisterite is a modulated 2:1-type phyllosilicate having ten octahedral sites with hydroxyl groups in trans, cis and combined trans-cis configurations. Each octahedral site, depending on its proximity to the layer modulation, is exposed to a different degree of distortion. The electric field gradient at the Fe site and the site distortion are used to propose a model for the site assignment and oxidation mechanism in bannisterite. The results show that two models are compatible with the experimental results of fitting the spectrum of bannisterite. However, the model which allows for site distortion accounts better for the observed line overlap of the Fe-[6](2+) sites. Accordingly, the octahedral sites with a greater degree of distortion are assigned to the Fe-[6](2+) with lower electric quadrupole splitting, and the octahedral sites with lower site distortion are assigned to the Fe-[6](2+) with higher electric quadrupole splitting. Moreover, the ease of oxidation decreases in the order trans > trans-cis > cis.}},
author = {{Ferrow, Embaie}},
issn = {{0026-461X}},
keywords = {{electric field gradient; distortion; bannisterite; Mossbauer; assignment; site}},
language = {{eng}},
number = {{2}},
pages = {{187--199}},
publisher = {{Mineralogical Society of Great Britain and Ireland}},
series = {{Mineralogical Magazine}},
title = {{Fe-57 Mossbauer effect study of bannisterite: a modulated 2 : 1-type phyllosilicate}},
url = {{http://dx.doi.org/10.1180/0026461067020323}},
doi = {{10.1180/0026461067020323}},
volume = {{70}},
year = {{2006}},
}