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| Titel |
Vibrational spectroscopic study of hydroxylpyromorphite-hydroxylmimetite solid solutions |
| VerfasserIn |
Monika Kwaśniak-Kominek, Jakub Matusik, Tomasz Bajda, Maciej Manecki |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250083693
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| Zusammenfassung |
| Hydroxylpyromorphite Pb5(PO4)3OH and hydroxylmimetite Pb5(AsO4)3OH minerals
belong to the apatite supergroup. Their structure allows isomorphous substitutions in both
cationic and anionic positions. They are isostructural with pyromorphite Pb5(PO4)3Cl and
mimetite Pb5(AsO4)3OH which are the end products of in situ phosphate induced
remediation of soils polluted with heavy metals e.g. lead. The research objective was to
synthesize and characterize the members of above mentioned solid solution. The minerals
were synthesized at room temperature and analyzed by X-Ray diffraction and Infrared
spectroscopy (FTIR-DRIFT).
The product syntheses was crystalline phase without any impurities within the detection
limit of XRD. Shifts of certain diffraction peaks were observed in solid solution series due to
replacement PO4 after AsO4.
The bands v3 and v4 attributed to vibrations in the PO4 and AsO4 tetrahedra appear at
1050-790 and 580-534 cm-1. Due to difference in atomic mass of P and As as well as
bonding strength of P-O and As-O the skeletal bands shift to lower wavenumbers with the
increase of AsO4 substitution.
The correlation between the position of vibrational modes and the chemical composition
is observed. The OH stretching mode in the FTIR spectra appears in the range of 3765-3552
cm-1 as a sharp band for the end members of the solid solution. For the intermediate
minerals the OH band becomes complex. The analysis of deconvoluted OH bands indicated
several vibrational modes which suggested a significant change of OH group local
environment induced by substitutions.
The study was supported by the AGH University of Science and Technology (Krakow,
Poland) as the research project No. 307 473Â 638. |
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