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ABSTRACT Quantification of Fe redox state and hydrogen content of amphibole provides information regarding the relationship between oxygen and water concentrations in terrestrial and planetary materials. Raman spectroscopy is a powerful technique due to its ability to characterize both %Fe3+and H2O from single crystal measurements, in addition to other chemical, mineralogical, and structural properties. Raman spectral measurements of amphibole minerals are used here to estimate %Fe3+(relative to total Fe) and H2O (wt%) contents using partial least squares (PLS) multivariate modeling. The accuracy of our model for prediction of %Fe3+is ± 8.11% (absolute) expressed as root‐mean‐square error (RMSE) of the entire data set, covering the range from 0 to 100% with anR2value of 0.85. The model for prediction of H2O has an internal RMSE of ± 0.09 wt% over the range from 0.1 to 1.9 wt% with anR2value of 0.95. Additional compositional model variables for predicting FeO, Fe2O3, MgO, CaO, Cr2O3, Al2O3, and TiO2have highR2values above 0.82; theR2value for SiO2is 0.63. Reliable models could not be achieved for MnO, Na2O, and K2O. The successful creation of our compositional models along with detailed analysis of the PLS model coefficients indicates that Raman spectroscopy can be used as a quantitative compositional tool in characterizing the amphibole mineral group. Quantifying amphibole compositions is useful for evaluating repositories of hydrogen, constraining the water budget of the terrestrial crust and interior, developing geothermobarometers and geohygrometers, and quantifying magma ascent rates.
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Machine-learning prediction of thermal expansion coefficient for perovskite oxides with experimental validation
The support vector machine model produced the best results with a root mean square error of 1.54 × 10−6K−1. The model was applied to 3 593 726 possible AA′BB′O3compositions, resulting in 150 451 predictions in the model confidence region.
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- Award ID(s):
- 2018427
- PAR ID:
- 10487809
- Publisher / Repository:
- RSC
- Date Published:
- Journal Name:
- Physical Chemistry Chemical Physics
- Volume:
- 25
- Issue:
- 46
- ISSN:
- 1463-9076
- Page Range / eLocation ID:
- 32123 to 32131
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1039/d3cp04017h
