English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/18266
Compartir / Impacto:
Estadísticas
Add this article to your Mendeley library MendeleyBASE
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Título

X-ray photoelectron spectroscopy characterization of natural chromite from Mercedita Mine (Eastern Cuba): quantification of the Fe3+/Fe2+ ratio

AutorFanlo, Isabel; Gervilla, Fernando; Mateo, Ester; Irusta, Silvia
Palabras claveChromite
FE3+/FE 2+
XPS
EPMA
Fecha de publicación1-feb-2008
EditorSchweizerbart science publishers
CitaciónEuropean Journal of Mineralogy 20(1): 125-129(5) (2008)
ResumenThe quantitative estimation of the Fe3+/Fe2+ ratio has a crucial interest to know the upper-mantle oxidation state. The relative proportions of Fe3+ and Fe2+ are usually estimated from electron microprobe analysis (EPMA) assuming chromite stoichiometry. In order to test a new technique to estimate the Fe3+/Fe2+ ratio and to avoid EPMA systematic errors, X-ray photo-electron spectroscopy (XPS) has been used to determine the Fe3+/Fe2+ ratio in four chromite samples from Cuba and the results compared with those obtained by EPMA. Due to the high surface sensitivity of XPS the samples were etched by removing the outermost layers by bombarding with an Ar+ ion gun. Therefore, the surface, as well as 8, 16 and 24 nm in-depth levels, were analyzed, revealing that the spectra change significantly with depth. Thus, from the surface down to 24 nm deep, Fe3+ concentrations decrease from values up to 10 at.% to values below the detection limit of XPS (0.1 at.%). By contrast, a systematic Fe3+ detection (between 1.32 and 4.04 at.%) was observed by EPMA. Consequently, XPS allows us to calculate ferric iron contents, a key datum for the calculation of the real structural formula of chromite. XPS can therefore be considered a useful tool in evaluating mantle oxidation state.
Versión del editorhttp://dx.doi.org/10.1127/0935-1221/2008/0020-1794
URIhttp://hdl.handle.net/10261/18266
DOI10.1127/0935-1221/2008/0020-1794
ISSN0210-3702
Aparece en las colecciones: (IACT) Artículos
Ficheros en este ítem:
No hay ficheros asociados a este ítem.
Mostrar el registro completo
 

Artículos relacionados:


NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.