Structure of Mn and Fe oxides and oxyhydroxides: A topological approach by EXAFS
Identifieur interne : 001588 ( Main/Exploration ); précédent : 001587; suivant : 001589Structure of Mn and Fe oxides and oxyhydroxides: A topological approach by EXAFS
Auteurs : A. Manceau [France] ; J. M. Combes [France]Source :
- Physics and Chemistry of Minerals [ 0342-1791 ] ; 1988-02-01.
Abstract
Abstract: The structure of Mn and Fe oxides and oxyhydroxides has been probed by EXAFS. It is shown that EXAFS spectroscopy is sensitive to the nature of interpolyhedral linkages relying on metal-two nearest metal distances. Spectra recorded at 290 K and 30 K indicate that intercationic distances can be determined by EXAFS with a good accuracy (0.02 Å) assuming a purely Gaussian distribution function, even at room temperature. Although the accuracy on atomic numbers determination is fair for these disordered systems, EXAFS can differentiate structures with contrasted edge- over corner-sharing ratio like pyrolusite, ramsdellite, todorokite and lithiophorite or lepidocrocite and goethite. A direct application of this result has shown that the proportion of pyrolusite domains within the lattice of nsutite from Ghana is equal to 35±15 percent. The systematic study of Mn dioxides also put forward the sensitivity of EXAFS to the presence of corner-sharing octahedra, with a detection limit found to be less than 8 percent. In spite of their similar XRD patterns, the EXAFS study of todorokite and asbolane confirms that they possess a distinct structure; that is, a tunnel structure for the former and a layered structure for the second. Such a topological approach has been used to probe the structure of ferruginous vernadite; a highly disordered iron-bearing Mn oxide. Fe and Mn K-edges EXAFS spectra are very dissimilar, traducing a different short range order. The Mn phase is constituted by MnO2 layers. Its large local structural order contrasts with the short range disorder of the iron phase. This hydrous Fe oxyhydroxide is constituted by face-, edge- and corner-sharing octahedra. This iron phase possesses the same local order as feroxy-hyte, but is long range disordered. The presence of face-sharing Fe(O,OH)6 octahedra prevents its direct solid-state transformation into well crystallized oxyhydroxides, and explains the necessary dissolution-reprecipitation mechanism generally invoked for the hydrous ferric gel → goethite transformation.
Url:
DOI: 10.1007/BF00307518
Affiliations:
Links toward previous steps (curation, corpus...)
- to stream Istex, to step Corpus: 001283
- to stream Istex, to step Curation: 000D91
- to stream Istex, to step Checkpoint: 000D74
- to stream Main, to step Merge: 001643
- to stream Main, to step Curation: 001588
Le document en format XML
<record><TEI wicri:istexFullTextTei="biblStruct"><teiHeader><fileDesc><titleStmt><title xml:lang="en">Structure of Mn and Fe oxides and oxyhydroxides: A topological approach by EXAFS</title><author><name sortKey="Manceau, A" sort="Manceau, A" uniqKey="Manceau A" first="A." last="Manceau">A. Manceau</name></author><author><name sortKey="Combes, J M" sort="Combes, J M" uniqKey="Combes J" first="J. M." last="Combes">J. M. Combes</name></author></titleStmt><publicationStmt><idno type="wicri:source">ISTEX</idno><idno type="RBID">ISTEX:FBFCD3DDC5F6A6965212DF1921F32E099CB5411E</idno><date when="1988" year="1988">1988</date><idno type="doi">10.1007/BF00307518</idno><idno type="url">https://api.istex.fr/document/FBFCD3DDC5F6A6965212DF1921F32E099CB5411E/fulltext/pdf</idno><idno type="wicri:Area/Istex/Corpus">001283</idno><idno type="wicri:explorRef" wicri:stream="Istex" wicri:step="Corpus" wicri:corpus="ISTEX">001283</idno><idno type="wicri:Area/Istex/Curation">000D91</idno><idno type="wicri:Area/Istex/Checkpoint">000D74</idno><idno type="wicri:explorRef" wicri:stream="Istex" wicri:step="Checkpoint">000D74</idno><idno type="wicri:doubleKey">0342-1791:1988:Manceau A:structure:of:mn</idno><idno type="wicri:Area/Main/Merge">001643</idno><idno type="wicri:Area/Main/Curation">001588</idno><idno type="wicri:Area/Main/Exploration">001588</idno></publicationStmt><sourceDesc><biblStruct><analytic><title level="a" type="main" xml:lang="en">Structure of Mn and Fe oxides and oxyhydroxides: A topological approach by EXAFS</title><author><name sortKey="Manceau, A" sort="Manceau, A" uniqKey="Manceau A" first="A." last="Manceau">A. Manceau</name><affiliation wicri:level="3"><country xml:lang="fr">France</country><wicri:regionArea>Laboratoire de Minéralogie-Cristallographie, Universités Paris 6 et 7, et CNRS UA09, Tour 16, 2ème Etage, 4 Place Jussieu, Paris</wicri:regionArea><placeName><region type="region">Île-de-France</region><region type="old region">Île-de-France</region><settlement type="city">Paris</settlement></placeName></affiliation></author><author><name sortKey="Combes, J M" sort="Combes, J M" uniqKey="Combes J" first="J. M." last="Combes">J. M. Combes</name><affiliation wicri:level="3"><country xml:lang="fr">France</country><wicri:regionArea>Laboratoire de Minéralogie-Cristallographie, Universités Paris 6 et 7, et CNRS UA09, Tour 16, 2ème Etage, 4 Place Jussieu, Paris</wicri:regionArea><placeName><region type="region">Île-de-France</region><region type="old region">Île-de-France</region><settlement type="city">Paris</settlement></placeName></affiliation></author></analytic><monogr></monogr><series><title level="j">Physics and Chemistry of Minerals</title><title level="j" type="abbrev">Phys Chem Minerals</title><idno type="ISSN">0342-1791</idno><idno type="eISSN">1432-2021</idno><imprint><publisher>Springer-Verlag</publisher><pubPlace>Berlin/Heidelberg</pubPlace><date type="published" when="1988-02-01">1988-02-01</date><biblScope unit="volume">15</biblScope><biblScope unit="issue">3</biblScope><biblScope unit="page" from="283">283</biblScope><biblScope unit="page" to="295">295</biblScope></imprint><idno type="ISSN">0342-1791</idno></series><idno type="istex">FBFCD3DDC5F6A6965212DF1921F32E099CB5411E</idno><idno type="DOI">10.1007/BF00307518</idno><idno type="ArticleID">BF00307518</idno><idno type="ArticleID">Art10</idno></biblStruct></sourceDesc><seriesStmt><idno type="ISSN">0342-1791</idno></seriesStmt></fileDesc><profileDesc><textClass></textClass><langUsage><language ident="en">en</language></langUsage></profileDesc></teiHeader><front><div type="abstract" xml:lang="en">Abstract: The structure of Mn and Fe oxides and oxyhydroxides has been probed by EXAFS. It is shown that EXAFS spectroscopy is sensitive to the nature of interpolyhedral linkages relying on metal-two nearest metal distances. Spectra recorded at 290 K and 30 K indicate that intercationic distances can be determined by EXAFS with a good accuracy (0.02 Å) assuming a purely Gaussian distribution function, even at room temperature. Although the accuracy on atomic numbers determination is fair for these disordered systems, EXAFS can differentiate structures with contrasted edge- over corner-sharing ratio like pyrolusite, ramsdellite, todorokite and lithiophorite or lepidocrocite and goethite. A direct application of this result has shown that the proportion of pyrolusite domains within the lattice of nsutite from Ghana is equal to 35±15 percent. The systematic study of Mn dioxides also put forward the sensitivity of EXAFS to the presence of corner-sharing octahedra, with a detection limit found to be less than 8 percent. In spite of their similar XRD patterns, the EXAFS study of todorokite and asbolane confirms that they possess a distinct structure; that is, a tunnel structure for the former and a layered structure for the second. Such a topological approach has been used to probe the structure of ferruginous vernadite; a highly disordered iron-bearing Mn oxide. Fe and Mn K-edges EXAFS spectra are very dissimilar, traducing a different short range order. The Mn phase is constituted by MnO2 layers. Its large local structural order contrasts with the short range disorder of the iron phase. This hydrous Fe oxyhydroxide is constituted by face-, edge- and corner-sharing octahedra. This iron phase possesses the same local order as feroxy-hyte, but is long range disordered. The presence of face-sharing Fe(O,OH)6 octahedra prevents its direct solid-state transformation into well crystallized oxyhydroxides, and explains the necessary dissolution-reprecipitation mechanism generally invoked for the hydrous ferric gel → goethite transformation.</div></front></TEI><affiliations><list><country><li>France</li></country><region><li>Île-de-France</li></region><settlement><li>Paris</li></settlement></list><tree><country name="France"><region name="Île-de-France"><name sortKey="Manceau, A" sort="Manceau, A" uniqKey="Manceau A" first="A." last="Manceau">A. Manceau</name></region><name sortKey="Combes, J M" sort="Combes, J M" uniqKey="Combes J" first="J. M." last="Combes">J. M. Combes</name></country></tree></affiliations></record>Pour manipuler ce document sous Unix (Dilib)
EXPLOR_STEP=$WICRI_ROOT/Wicri/Terre/explor/CobaltMaghrebV1/Data/Main/Exploration
HfdSelect -h $EXPLOR_STEP/biblio.hfd -nk 001588 | SxmlIndent | more
Ou
HfdSelect -h $EXPLOR_AREA/Data/Main/Exploration/biblio.hfd -nk 001588 | SxmlIndent | more
Pour mettre un lien sur cette page dans le réseau Wicri
{{Explor lien
|wiki= Wicri/Terre
|area= CobaltMaghrebV1
|flux= Main
|étape= Exploration
|type= RBID
|clé= ISTEX:FBFCD3DDC5F6A6965212DF1921F32E099CB5411E
|texte= Structure of Mn and Fe oxides and oxyhydroxides: A topological approach by EXAFS
}}
| This area was generated with Dilib version V0.6.32. |  |