Fe microenvironments in heat treated rare-earth exchanged montmorillonites

The rare-earth bentonites were prepared from Ca-bentonite by suspending Ca-bentonite in rare-earth (Ce, La, Y) perchlorate solution. 57 Fe Mössbauer spectra of rare earth montmorillonites before heat treatments showed a doublet envelop at room temperature, reflecting dominantly Fe 3+ assigned to (ci...

Full description

Saved in:
Bibliographic Details
Published in:Hyperfine interactions 2019-12, Vol.240 (1), p.1-7, Article 87
Main Authors: Kuzmann, Erno, Kovács, Eszter M., Homonnay, Zoltan, Csákvári, Szabolcs, Klencsár, Zoltan, Kónya, Peter, Nagy, Noemi M., Kónya, Jozsef
Format: Article
Language:English
Subjects:
19-23 May 2019
Atomic
Bentonite
Condensed Matter Physics
France
Hadrons
Heat exchange
Heat treatment
Heavy Ions
Interlayers
Iron
Iron 57
Magnetic resonance
Mica
Molecular
Montmorillonite
Montpellier
Mossbauer spectroscopy
Muscovite
Nuclear Physics
Optical and Plasma Physics
Phase transitions
Physics
Physics and Astronomy
Proceedings of the 5th Mediterranean Conference on the Applications of the Mössbauer Effect (MECAME 2019) and 41st Workshop of the French-speaking Group of Mössbauer Spectroscopy (GFSM 2019)
Rare earth elements
Spectra
Spectrum analysis
Surfaces and Interfaces
Thin Films
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The rare-earth bentonites were prepared from Ca-bentonite by suspending Ca-bentonite in rare-earth (Ce, La, Y) perchlorate solution. 57 Fe Mössbauer spectra of rare earth montmorillonites before heat treatments showed a doublet envelop at room temperature, reflecting dominantly Fe 3+ assigned to (cis) octahedral site in the montmorillonite. At the same time, the 80 K spectra of these rare-earth exchanged montmorillonites revealed an additional magnetically split component, too, associated with iron atoms intercalated in the interlayer space. In the case of heat treated samples (250 °C, 360 °C and 500 °C for 4 h), a new doublet component associated with Fe 3+ at trans octahedral site, appeared in both the 295 K and 80 K Mössbauer spectra. Powder X-ray diffractometry (XRD) measurements of the heat treated rare earth montmorillonites revealed that a gradual mineral phase transformation of montmorillonite to muscovite occurred upon the applied heat treatments, being consistent with the completing electron magnetic resonance (EMR) and Mössbauer spectroscopy (MS) results.
ISSN:0304-3843
1572-9540
DOI:10.1007/s10751-019-1622-7