Abstract
Synchrotron radiation has been used to collect high-resolution Fe K absorption near-edge spectra of a suite of Fe minerals and compounds having a range of Fe environments. These spectra, along with those of previous workers, indicate that the number, position, and intensity of near-edge features are characteristic of Fe valence and general site geometry. For example, the crest of the K-edge for Fe2+ in a six-coordinated site in the oxides studied is about 3 eV lower in energy than that for Fe3+ in a similar site. The K-edge crest for Fe3+ in a four-coordinated site is 1 to 2 eV lower than for Fe3+ in a regular site. The shape of the edge crest is sensitive to the details of first-neighbor bonding distances, tending to be broader in species with irregular Fe sites and varying in energy according to the average bond length. Comparison with Ca2+ and Zn2+ spectra from the literature is made and the applicability and utility of edge measurements discussed.
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Waychunas, G.A., Apted, M.J. & Brown, G.E. X-ray K-edge absorption spectra of Fe minerals and model compounds: Near-edge structure. Phys Chem Minerals 10, 1–9 (1983). https://doi.org/10.1007/BF01204319
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DOI: https://doi.org/10.1007/BF01204319


