The melting curve of iron at the pressures of the Earth's core from ab initio calculations

Nature ◽  
10.1038/46758 ◽  
1999 ◽  
Vol 401 (6752) ◽  
pp. 462-464 ◽  
Author(s):  
D. Alfè ◽  
M. J. Gillan ◽  
G. D. Price
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Melting Curve ◽  
Earth’S Core ◽  
Earth's Core

Constraints on the composition of the Earth's core from ab initio calculations

Nature ◽  
2000 ◽  
Vol 405 (6783) ◽  
pp. 172-175 ◽  
Author(s):  
D. Alfè ◽  
M. J. Gillan ◽  
G. D. Price
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Earth’S Core ◽  
Earth's Core

scholarly journals New high-pressure phases of Fe7N3 and Fe7C3 stable at Earth's core conditions: evidences for carbon–nitrogen isomorphism in Fe-compounds

RSC Advances ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 3577-3581 ◽  
Author(s):  
Nursultan Sagatov ◽  
Pavel N. Gavryushkin ◽  
Talgat M. Inerbaev ◽  
Konstantin D. Litasov
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Ab Initio ◽  
Structure Prediction ◽  
Harmonic Approximation ◽  
Crystal Structure Prediction ◽  
Earth’S Core ◽  
Earth's Core ◽  
Core Conditions

We carried out ab initio calculations on the crystal structure prediction and determination of P–T diagrams within the quasi-harmonic approximation for Fe7N3 and Fe7C3.

scholarly journals Ab Initio Molecular Dynamics Investigation of Molten Fe–Si–O in Earth's Core

2019 ◽  
Vol 46 (12) ◽  
pp. 6397-6405 ◽  
Author(s):  
Dongyang Huang ◽  
James Badro ◽  
John Brodholt ◽  
Yunguo Li
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Ab Initio Molecular Dynamics ◽  
Earth’S Core ◽  
Earth's Core

scholarly journals Origins of ultralow velocity zones through slab-derived metallic melt

2016 ◽  
Vol 113 (20) ◽  
pp. 5547-5551 ◽  
Author(s):  
Jiachao Liu ◽  
Jie Li ◽  
Rostislav Hrubiak ◽  
Jesse S. Smith
Keyword(s):  
Large Scale ◽  
Thermal Structure ◽  
Melting Curve ◽  
Oceanic Lithosphere ◽  
Earth’S Core ◽  
Eutectic Melting ◽  
Earth's Core ◽  
Mantle Boundary ◽  
Core Mantle Boundary ◽  
Metallic Melt

Understanding the ultralow velocity zones (ULVZs) places constraints on the chemical composition and thermal structure of deep Earth and provides critical information on the dynamics of large-scale mantle convection, but their origin has remained enigmatic for decades. Recent studies suggest that metallic iron and carbon are produced in subducted slabs when they sink beyond a depth of 250 km. Here we show that the eutectic melting curve of the iron−carbon system crosses the current geotherm near Earth’s core−mantle boundary, suggesting that dense metallic melt may form in the lowermost mantle. If concentrated into isolated patches, such melt could produce the seismically observed density and velocity features of ULVZs. Depending on the wetting behavior of the metallic melt, the resultant ULVZs may be short-lived domains that are replenished or regenerated through subduction, or long-lasting regions containing both metallic and silicate melts. Slab-derived metallic melt may produce another type of ULVZ that escapes core sequestration by reacting with the mantle to form iron-rich postbridgmanite or ferropericlase. The hypotheses connect peculiar features near Earth's core−mantle boundary to subduction of the oceanic lithosphere through the deep carbon cycle.

The ab initio simulation of the Earth's core

2002 ◽  
Vol 360 (1795) ◽  
pp. 1227-1244 ◽  
Author(s):  
D. Alfè ◽  
M. J. Gillan ◽  
L. Vočadlo ◽  
J. Brodholt ◽  
G. D. Price
Keyword(s):  
Ab Initio ◽  
Earth’S Core ◽  
Ab Initio Simulation ◽  
Earth's Core

Thermodynamics from first principles: temperature and composition of the Earth’s core

2003 ◽  
Vol 67 (1) ◽  
pp. 113-123 ◽  
Author(s):  
D. Alfé ◽  
M. J. Gillan ◽  
G. D. Price
Keyword(s):  
Melting Temperature ◽  
First Principles ◽  
Inner Core ◽  
Melting Curve ◽  
Outer Core ◽  
Earth’S Core ◽  
Earth's Core ◽  
The Core ◽  
Core Conditions ◽  
Main Ideas

AbstractWe summarize the main ideas used to determine the thermodynamic properties of pure systems and binary alloys from first principles calculations. These are based on the ab initio calculations of free energies. As an application we present the study of iron and iron alloys under Earth,s core conditions. In particular, we report the whole melting curve of iron under these conditions, and we put constraints on the composition of the core. We found that iron melts at 6350士600 K at the pressure corresponding to the boundary between the solid inner core and the liquid outer core (ICB). We show that the core could not have been formed from a binary mixture of Fe with S, Si or O and we propose a ternary or quaternary mixture with 8—10% of S/Si in both liquid and solid and an additional ~8% of oxygen in the liquid. Based on this proposed composition we calculate the shift of melting temperature with respect to the melting temperature of pure Fe of ~—700 K, so that our best estimate for the temperature of the Earth's core at ICB is 5650±600 K.

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