Vibrational spectroscopy of the phosphate mineral lazulite – (Mg, Fe)Al2(PO4)2·(OH)2 found in the Minas Gerais, Brazil
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15/04/2013
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Resumo |
This research was done on lazulite samples from the Gentil mine, a lithium bearing pegmatite located in the municipality of Mendes Pimentel, Minas Gerais, Brazil. Chemical analysis was carried out by electron microprobe analysis and indicated a magnesium rich phase with partial substitution of iron. Traces of Ca and Mn, (which partially replaced Mg) were found. The calculated chemical formula of the studied sample is: (Mg0.88, Fe0.11)Al1.87(PO4)2.08(OH)2.02. The Raman spectrum of lazulite is dominated by an intense sharp band at 1060 cm-1 assigned to PO stretching vibrations of of tetrahedral [PO4] clusters presents into the HPO2/4- units. Two Raman bands at 1102 and 1137 cm-1 are attributed to both the HOP and PO antisymmetric stretching vibrations. The two infrared bands at 997 and 1007 cm-1 are attributed to the m1 PO3/4- symmetric stretching modes. The intense bands at 1035, 1054, 1081, 1118 and 1154 cm-1 are assigned to the v3PO3/4- antisymmetric stretching modes from both the HOP and tetrahedral [PO4] clusters. A set of Raman bands at 605, 613, 633 and 648 cm-1 are assigned to the m4 out of plane bending modes of the PO4, HPO4 and H2PO4 units. Raman bands observed at 414, 425, 460, and 479 cm-1 are attributed to the m2 tetrahedral PO4 clusters, HPO4 and H2PO4 bending modes. The intense Raman band at 3402 and the infrared band at 3403 cm-1 are assigned to the stretching vibration of the OH units. A combination of Raman and infrared spectroscopy enabled aspects of the molecular structure of the mineral lazulite to be understood. |
Formato |
application/pdf |
Identificador | |
Publicador |
Elsevier BV |
Relação |
http://eprints.qut.edu.au/61334/3/lazulite_authors_version_combined.pdf DOI:10.1016/j.saa.2013.01.056 Frost, Ray L., Xi, Yunfei, Beganovic, Martina, Belotti, Fernanda Maria, & Scholz, Ricardo (2013) Vibrational spectroscopy of the phosphate mineral lazulite – (Mg, Fe)Al2(PO4)2·(OH)2 found in the Minas Gerais, Brazil. Spectrochimica Acta Part A : Molecular and Biomolecular Spectroscopy, 107, pp. 241-247. |
Direitos |
Copyright 2013 Elsevier B.V. All rights reserved. This is the author's version of a work that was accepted for publication in Spectrochimica Acta Part A : Molecular and Biomolecular Spectroscopy. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Spectrochimica Acta Part A : Molecular and Biomolecular Spectroscopy, [107, (2013)] http://dx.doi.org/10.1016/j.saa.2013.01.056 |
Fonte |
School of Chemistry, Physics & Mechanical Engineering; Science & Engineering Faculty |
Palavras-Chave | #030606 Structural Chemistry and Spectroscopy #Raman spectroscopy #Lazulite #Infrared spectroscopy #Phosphate #Pegmatite |
Tipo |
Journal Article |