Vibrational spectroscopic characterization of the phosphate mineral series eosphorite-childrenite-(Mn,Fe)Al(PO4)(OH)2 (H2O).

The phosphate mineral series eosphorite–childrenite–(Mn,Fe)Al(PO4)(OH)2•(H2O) has been studied using a combination of electron probe analysis and vibrational spectroscopy. Eosphorite is the manganese rich mineral with lower iron content in comparison with the childrenite which has higher iron and lo...

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Detalhes bibliográficos
Autores: Frost, Ray Leslie, Xi, Yunfei, Cipriano, Ricardo Augusto Scholz, López, Andrés, Lima, Rosa Malena Fernandes, Ferreira, Claudiane Moraes
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2013
País:Brasil
Recursos:Universidade Federal de Ouro Preto (UFOP)
Repositório:Repositório Institucional da UFOP
Idioma:inglês
OAI Identifier:oai:repositorio.ufop.br:123456789/4151
Acesso em linha:http://www.repositorio.ufop.br/handle/123456789/4151
https://doi.org/10.1016/j.vibspec.2013.03.005
Access Level:Acceso aberto
Palavra-chave:Eosphorite
Childrenite
Phosphate
Pegmatite
Raman spectroscopy
Descrição
Resumo:The phosphate mineral series eosphorite–childrenite–(Mn,Fe)Al(PO4)(OH)2•(H2O) has been studied using a combination of electron probe analysis and vibrational spectroscopy. Eosphorite is the manganese rich mineral with lower iron content in comparison with the childrenite which has higher iron and lower manganese content. The determined formulae of the two studied minerals are: (Mn0.72,Fe0.13,Ca0.01)(Al)1.04(PO4, OHPO3)1.07(OH1.89,F0.02)•0.94(H2O) for SAA-090 and (Fe0.49,Mn0.35,Mg0.06,Ca0.04)(Al)1.03(PO4, OHPO3)1.05(OH)1.90•0.95(H2O) for SAA-072. Raman spectroscopy enabled the observation of bands at 970 cm−1 and 1011 cm−1 assigned to monohydrogen phosphate, phosphate and dihydrogen phosphate units. Differences are observed in the area of the peaks between the two eosphorite minerals. Raman bands at 562 cm−1, 595 cm−1, and 608 cm−1 are assigned to the _4 bending modes of the PO4, HPO4 and H2PO4 units; Raman bands at 405 cm−1, 427 cm−1 and 466 cm−1 are attributed to the _2 modes of these units. Raman bands of the hydroxyl and water stretching modes are observed. Vibrational spectroscopy enabled details of the molecular structure of the eosphorite mineral series to be determined.