The Influence of Si, C, and S on the Structure and Dynamics of Liquid Fe-Ni Alloys Under High Pressure
ORAL
Abstract
The effect of light elements (LEs) such as silicon, carbon, and sulfur on the physical properties of liquid iron–nickel alloys under conditions representative of the Earth's outer core is fundamental to understanding its composition and dynamics.
We present first-principles molecular dynamics simulations of liquid Fe-Ni alloys with ~5.5 wt% Ni and varying concentrations of Si (5.3 wt%), S (6.0 wt%), and C (2.3 wt%) at the extreme pressure-temperature conditions (150–330 GPa, 4000–6300 K) of the Earth's liquid outer core.
We find Si incorporates substitutionally, while C occupies interstitial sites. Sulfur transitions from interstitial to substitutional under increasing pressure. Furthermore, we quantify how these LEs influence some dynamic properties essential to core dynamics, including self-diffusion coefficients and adiabatic sound velocities.
We present first-principles molecular dynamics simulations of liquid Fe-Ni alloys with ~5.5 wt% Ni and varying concentrations of Si (5.3 wt%), S (6.0 wt%), and C (2.3 wt%) at the extreme pressure-temperature conditions (150–330 GPa, 4000–6300 K) of the Earth's liquid outer core.
We find Si incorporates substitutionally, while C occupies interstitial sites. Sulfur transitions from interstitial to substitutional under increasing pressure. Furthermore, we quantify how these LEs influence some dynamic properties essential to core dynamics, including self-diffusion coefficients and adiabatic sound velocities.
*Work supported by University of Valladolid (GIR 18.46.20)
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Presenters
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David J Gonzalez
- University de Valladolid