Vibrational spectroscopic characterization of the phosphate mineral bermanite Mn2+Mn23+(PO4)2(OH)2 4(H2O).

Bermanite Mn^2+Mn2^3+(PO4)2(OH)2.4(H2O) is a mixed valent hydrated hydroxy phosphate mineral. The mineral is reddish-brown and occurs in crystal aggregates and as lamellar masses. Bermanite is a common mineral in granitic pegmatites. The chemical composition of bermanite was obtained using EDS techn...

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Detalles Bibliográficos
Autores: Frost, Ray Leslie, Xi, Yunfei, Cipriano, Ricardo Augusto Scholz, Belotti, Fernanda Maria
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2012
País:Brasil
Institución:Universidade Federal de Ouro Preto (UFOP)
Repositorio:Repositório Institucional da UFOP
Idioma:inglés
OAI Identifier:oai:repositorio.ufop.br:123456789/4148
Acceso en línea:http://www.repositorio.ufop.br/handle/123456789/4148
https://doi.org/10.1016/j.saa.2012.12.021
Access Level:acceso abierto
Palabra clave:Raman spectroscopyz
Bermanite
Infrared spectroscopy
Phosphate
Pegmatite
Descripción
Sumario:Bermanite Mn^2+Mn2^3+(PO4)2(OH)2.4(H2O) is a mixed valent hydrated hydroxy phosphate mineral. The mineral is reddish-brown and occurs in crystal aggregates and as lamellar masses. Bermanite is a common mineral in granitic pegmatites. The chemical composition of bermanite was obtained using EDS techniques. We have studied the molecular structure of bermanite using vibrational spectroscopy. The mineral is characterized by a Raman doublet at 991 and 999 cm^-1 attributed to the phosphate stretching mode of two non-equivalent phosphate units. Raman bands at 1071, 1117 and 1142 cm^-1 are assigned to the phosphate antisymmetric stretching modes. The hydroxyl stretching spectral region is complex with overlapping bands attributed to water and hydroxyl stretching vibrations. Vibrational spectroscopy proves most useful for the study of the mineral bermanite.