X-ray microprobe analysis of iron oxidation states in silicates and oxides using X-ray absorption near edge structure (XANES)

Journal Article · Thu Dec 01 00:00:00 EST 1994 · Geochimica et Cosmochimica Acta

DOI:https://doi.org/10.1016/0016-7037(94)90305-0· OSTI ID:28574

Bajt, S; Sutton, R ^[1]; Delaney, J S ^[2]

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1. Univ. of Chicago, IL (United States)
2. Rutgers Univ., New Brunswick, NJ (United States)

Initial results are reported on a new microprobe technique for determining Fe{sup 3+}/{Sigma}Fe ratios in Fe-bearing minerals. The technique is based on the energy shift of a pre-edge peak in X-ray absorption near-edge structure (XANES) spectra obtained using the synchrotron X-ray fluorescence microprobe. A linear relationship between pre-edge peak energy and iron oxidation state was observed for oxide and silicate standards. Reasonable iron oxidation state results were obtained for pallasitic olivine, acmite, altered magnetites, and synthetic wuestite. Direct measurements of Fe{sup 3+}/{Sigma}Fe in coexisting phases is feasible using this technique.

• Research Organization: Brookhaven National Lab. (BNL), Upton, NY (United States)
• DOE Contract Number: FG02-92ER14244; AC02-76CH00016
• OSTI ID: 28574
• Journal Information: Geochimica et Cosmochimica Acta, Vol. 58, Issue 23; Other Information: PBD: Dec 1994
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
IRON
OXIDATION
ISOTOPE RATIO
ELECTRON MICROPROBE ANALYSIS
FEASIBILITY STUDIES
OLIVINE
SILICATES
X-RAY FLUORESCENCE ANALYSIS
GEOCHEMISTRY