Quantitative determination of iron oxidation state in tourmaline-supergroup minerals using electron microprobe
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| Year of publication | 2024 |
| Type | Appeared in Conference without Proceedings |
| MU Faculty or unit | |
| Citation | |
| Description | The flank method, developed by Höfer et al. (1994), quantitatively determines the Fe oxidation state in minerals using an electron microprobe. It is based on measuring X-ray intensities at specific spectral positions (FeL? and FeLß flanks) where the largest differences between Fe2+ and Fe3+ spectra are observed. The calibration of the flank method for tourmaline-supergroup minerals is based on measuring the FeL?/FeLß flank X-ray intensities on natural tourmaline standards with low Fe3+ content, previously determined by Mössbauer Spectroscopy, and on their annealed and fully oxidized equivalents. Optimal conditions include 15 kV accelerating voltage and 50 nA beam current. Using parameters defining the calibration space, a relationship was derived to calculate the Fe3+/?Fe content in tourmalines. The accuracy of the methodology was tested on a series of natural tourmalines with known variable Fe3+ content. The calculated results are comparable with data from Mössbauer Spectroscopy. |
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