scholarly journals THE OH COMPONENTS IN GARNETS FROM DIFFERENTGEOLOGICAL ENVIRONMENTS: P-T AND BULK COMPOSITION CONSTRAINTS

2013 ◽  
Author(s):  
Danielle Piuzana ◽  
Cristiane Castañeda ◽  
Sigrid Griet Eeckhout ◽  
Eddy De Grave
Keyword(s):  
Mössbauer Spectroscopy ◽  
Ferric Iron ◽  
Mossbauer Spectroscopy ◽  
Bulk Composition ◽  
Structural Disorder ◽  
Garnet Structure ◽  
Central Brazil ◽  
Mößbauer Spectroscopy ◽  
Dodecahedral Site ◽  
Petrogenetic Indicator

Metamorphic garnet from the Anápolis-Itauçu Complex (AIC), central Brazil, were investigated by electron microprobe analyses and Mössbauer spectroscopy, in order to contribute on their geological history. The data were further extended by magmatic samples from complex and simple pegmatites, as reported by Eeckhout et al. (2002). Three clear chemical tendencies within garnets from AIC rocks were revealed. From Mössbauer spectroscopy data it is obvious that ferrous iron is present at dodecahedral site. Very small amounts of ferric iron at octahedral site of garnet structure are additionally present in garnets from sample of ultra-high temperature (UHT) granulites from AIC, implying slightly oxidizing conditions during this metamorphicevent. In addition, a higher degree of structural disorder has been discerned in these samples.Keywords: Garnet, petrogenetic indicator, hydroxyl, Mössbauer spectroscopy.

Accurate determination of ferric iron in garnets by bulk Mossbauer spectroscopy and synchrotron micro-XANES

2012 ◽  
Vol 97 (10) ◽  
pp. 1726-1740 ◽  
Author(s):  
M. D. Dyar ◽  
E. A. Breves ◽  
E. Emerson ◽  
S. W. Bell ◽  
M. Nelms ◽  
...  
Keyword(s):  
Mössbauer Spectroscopy ◽  
Ferric Iron ◽  
Mossbauer Spectroscopy ◽  
Accurate Determination ◽  
Mößbauer Spectroscopy

scholarly journals Structural disorder in Lix(C5H5N)yFe2−zSe2 and CsxFe2−zSe2 superconductors studied by Mössbauer spectroscopy

2016 ◽  
Vol 406 ◽  
pp. 244-250 ◽  
Author(s):  
K. Komędera ◽  
A.K. Jasek ◽  
A. Błachowski ◽  
K. Ruebenbauer ◽  
J. Żukrowski ◽  
...  
Keyword(s):  
Mössbauer Spectroscopy ◽  
Mossbauer Spectroscopy ◽  
Structural Disorder ◽  
Mößbauer Spectroscopy

scholarly journals Processes and Conditions of the Origin for Fe3+-Bearing Magnesiowüstite under Lithospheric Mantle Pressures and Temperatures

Minerals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 474
Author(s):  
Bataleva ◽  
Palyanov ◽  
Borzdov ◽  
Bayukov
Keyword(s):  
Mössbauer Spectroscopy ◽  
Lithospheric Mantle ◽  
Redox Reactions ◽  
Ferric Iron ◽  
Mossbauer Spectroscopy ◽  
Formation Processes ◽  
Metal Carbides ◽  
Mößbauer Spectroscopy ◽  
Metal Carbonate ◽  
Reducing Conditions

An experimental study, implicated in the revealing of the conditions for the origin for Fe3+-bearing magnesiowüstite in the lithospheric mantle, was performed using Mössbauer spectroscopy of pre-synthesized samples. Experiments were carried out using a multi-anvil high-pressure split-sphere apparatus at 6.3–7.5 GPa, in the range of 1100–1650 °C in carbonate-metal, carbonate–oxide-metal, carbonate-oxide, carbide-oxide and carbonate–metal- sulphur systems. In three experimental series, oxygen fugacity gradient in the samples was created, which enabled the study of the processes of magnesiowüstite formation under oxidizing and reducing conditions (ΔlogfO2 (FMQ) values from −1 to −5). It was established that Fe3+-bearing magnesiowüstite can form both in assemblage with oxidized phases, such as carbonate or with reduced ones—metal, carbides, sulphides, graphite and diamond. According to the Mössbauer spectroscopy, the composition of synthesized magnesiowüstite varied within a range of Fe3+/ΣFe values from 0 to 0.3, with IV and VI coordination of Fe3+ depending on P, T, fO2, x-parameters. It was established that Fe3+-bearing magnesiowüstite formation processes under upper mantle P,T-conditions include redox reactions, with magnesiowüstite being (1) reductant or (2) product of interaction, (3) crystallization processes of magnesiowüstite from an oxidized melt, where magnesiowüstite acts as a sink for ferric iron and (4) iron disproportionation.

Local Structural Disorder and Relaxation in SnO2 Nanostructures Studied by 119Sn MAS NMR and 119Sn Mössbauer Spectroscopy

2011 ◽  
Vol 115 (14) ◽  
pp. 6433-6437 ◽  
Author(s):  
Sylvio Indris ◽  
Marco Scheuermann ◽  
Sebastian M. Becker ◽  
Vladimir Šepelák ◽  
Robert Kruk ◽  
...  
Keyword(s):  
Mössbauer Spectroscopy ◽  
Mossbauer Spectroscopy ◽  
Structural Disorder ◽  
Mas Nmr ◽  
Sno2 Nanostructures ◽  
119Sn Mössbauer Spectroscopy ◽  
Mößbauer Spectroscopy
Sign in / Sign up

Export Citation Format

Share Document