Spin State and Structural Stability of Ferropericlase up to 30 Mbar
Abstract
Ferropericlase (Fp), (Mg1-xFex)O, the second most abundant mineral in the Earth mantle, is expected to be an essential component of the deep mantle of terrestrial super-Earths. Thus, an understanding of Fp across a wide range of pressure, temperature, and iron concentrations is crucial to model the internal structure and dynamics of terrestrial exoplanets. Understanding pressure-induced electronic spin transitions in iron in Fp is a challenging problem given the strongly correlated nature of iron. Here, we present an LDA+Usc study of the structure and magnetic ground state of Fp from 200 GPa to 3 TPa in a range of iron concentrations, xFe, varying from ~3% to 25%. The quasiharmonic approximation (QHA) is used to compute the free energy and stability field of the B1 an B2 phases, as well as thermodynamic properties of these phases up to 3 Mbar. Such properties will be useful modeling the mantle of super-Earth-type planets.
Research supported by NSF grant EAR-1918126- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMMR0160006W
- Keywords:
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- 3909 Elasticity and anelasticity;
- MINERAL PHYSICS;
- 3919 Equations of state;
- MINERAL PHYSICS;
- 3924 High-pressure behavior;
- MINERAL PHYSICS;
- 3672 Planetary mineralogy and petrology;
- MINERALOGY AND PETROLOGY;
- 5430 Interiors;
- PLANETARY SCIENCES: SOLID SURFACE PLANETS