Accurate predictions of iron redox state in silicate glasses: A multivariate approach using X-ray absorption spectroscopy
American Mineralogist, 2016•degruyter.com
Pre-edge features in the K absorption edge of X-ray absorption spectra are commonly used
to predict Fe3+ valence state in silicate glasses. However, this study shows that using the
entire spectral region from the pre-edge into the extended X-ray absorption fine-structure
region provides more accurate results when combined with multivariate analysis techniques.
The least absolute shrinkage and selection operator (lasso) regression technique yields%
Fe3+ values that are accurate to±3.6% absolute when the full spectral region is employed …
to predict Fe3+ valence state in silicate glasses. However, this study shows that using the
entire spectral region from the pre-edge into the extended X-ray absorption fine-structure
region provides more accurate results when combined with multivariate analysis techniques.
The least absolute shrinkage and selection operator (lasso) regression technique yields%
Fe3+ values that are accurate to±3.6% absolute when the full spectral region is employed …
Abstract
Pre-edge features in the K absorption edge of X-ray absorption spectra are commonly used to predict Fe3+ valence state in silicate glasses. However, this study shows that using the entire spectral region from the pre-edge into the extended X-ray absorption fine-structure region provides more accurate results when combined with multivariate analysis techniques. The least absolute shrinkage and selection operator (lasso) regression technique yields %Fe3+ values that are accurate to ±3.6% absolute when the full spectral region is employed. This method can be used across a broad range of glass compositions, is easily automated, and is demonstrated to yield accurate results from different synchrotrons. It will enable future studies involving X-ray mapping of redox gradients on standard thin sections at 1 × 1 μm pixel sizes.
De Gruyter