Extreme pressures and temperatures are known to drastically affect the chemistry of iron oxides, resulting in numerous compounds forming homologous series nFeOmFe2O3 and the appearance of FeO2. Here, based on the results of in situ single-crystal x-ray diffraction, Mössbauer spectroscopy, x-ray absorption spectroscopy, and density-functional theory+dynamical mean-field theory calculations, we demonstrate that iron in high-pressure cubic FeO2 and isostructural FeO2H0.5 is ferric (Fe3+), and oxygen has a formal valence less than 2. Reduction of oxygen valence from 2, common for oxides, down to 1.5 can be explained by a formation of a localized hole at oxygen sites.

Koemets, E., Leonov, I., Bykov, M., Bykova, E., Chariton, S., Aprilis, G., et al. (2021). Revealing the Complex Nature of Bonding in the Binary High-Pressure Compound FeO2. PHYSICAL REVIEW LETTERS, 126(10) [10.1103/PhysRevLett.126.106001].

Revealing the Complex Nature of Bonding in the Binary High-Pressure Compound FeO2

Cerantola, V;
2021

Abstract

Extreme pressures and temperatures are known to drastically affect the chemistry of iron oxides, resulting in numerous compounds forming homologous series nFeOmFe2O3 and the appearance of FeO2. Here, based on the results of in situ single-crystal x-ray diffraction, Mössbauer spectroscopy, x-ray absorption spectroscopy, and density-functional theory+dynamical mean-field theory calculations, we demonstrate that iron in high-pressure cubic FeO2 and isostructural FeO2H0.5 is ferric (Fe3+), and oxygen has a formal valence less than 2. Reduction of oxygen valence from 2, common for oxides, down to 1.5 can be explained by a formation of a localized hole at oxygen sites.
Articolo in rivista - Articolo scientifico
iron oxides; XRD; Mössbauer spectroscopy; extreme conditions; diamond anvil cell; XAS; DFT; laser heating; synchrotron
English
2021
126
10
106001
none
Koemets, E., Leonov, I., Bykov, M., Bykova, E., Chariton, S., Aprilis, G., et al. (2021). Revealing the Complex Nature of Bonding in the Binary High-Pressure Compound FeO2. PHYSICAL REVIEW LETTERS, 126(10) [10.1103/PhysRevLett.126.106001].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/397746
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