scholarly journals The effect of Si and S on the stability of bcc iron with respect to tetragonal strain at the Earth's inner core conditions

2013 ◽  
Vol 40 (12) ◽  
pp. 2958-2962 ◽  
Author(s):  
Hang Cui ◽  
Zhigang Zhang ◽  
Yigang Zhang
Keyword(s):  
Inner Core ◽  
Bcc Iron ◽  
Earth’S Inner Core ◽  
Core Conditions ◽  
The Stability

scholarly journals No system-size anomalies in entropy of bcc iron at Earth’s inner-core conditions

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Andrew J. Schultz ◽  
Sabry G. Moustafa ◽  
David A. Kofke
Keyword(s):  
Inner Core ◽  
System Size ◽  
Bcc Iron ◽  
Earth’S Inner Core ◽  
Core Conditions

Measuring the melting curve of iron at super-Earth core conditions

Science ◽  
2022 ◽  
Vol 375 (6577) ◽  
pp. 202-205
Author(s):  
Richard G. Kraus ◽  
Russell J. Hemley ◽  
Suzanne J. Ali ◽  
Jonathan L. Belof ◽  
Lorin X. Benedict ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Inner Core ◽  
Melting Curve ◽  
Radiation Shielding ◽  
Metal Core ◽  
Earth Core ◽  
Core Boundary ◽  
Earth Like Planets ◽  
Earth’S Inner Core ◽  
Core Conditions

Terapascal iron-melting temperature The pressure and temperature conditions at which iron melts are important for terrestrial planets because they determine the size of the liquid metal core, an important factor for understanding the potential for generating a radiation-shielding magnetic field. Kraus et al . used laser-driven shock to determine the iron-melt curve up to a pressure of 1000 gigapascals (see the Perspective by Zhang and Lin). This value is about three times that of the Earth’s inner core boundary. The authors found that the liquid metal core lasted the longest for Earth-like planets four to six times larger in mass than the Earth. —BG

scholarly journals Stability of body-centered cubic iron–magnesium alloys in the Earth's inner core

2009 ◽  
Vol 106 (37) ◽  
pp. 15560-15562 ◽  
Author(s):  
Krisztina Kádas ◽  
Levente Vitos ◽  
Börje Johansson ◽  
Rajeev Ahuja
Keyword(s):  
Inner Core ◽  
The Body ◽  
Mg Alloys ◽  
Functional Study ◽  
Body Centered Cubic ◽  
Calculated Density ◽  
The Core ◽  
Earth’S Inner Core ◽  
Core Conditions ◽  
Bcc Phase

The composition and the structure of the Earth's solid inner core are still unknown. Iron is accepted to be the main component of the core. Lately, the body-centered cubic (bcc) phase of iron was suggested to be present in the inner core, although its stability at core conditions is still in discussion. The higher density of pure iron compared with that of the Earth's core indicates the presence of light element(s) in this region, which could be responsible for the stability of the bcc phase. However, so far, none of the proposed composition models were in full agreement with seismic observations. The solubility of magnesium in hexagonal Fe has been found to increase significantly with increasing pressure, suggesting that Mg can also be an important element in the core. Here, we report a first-principles density functional study of bcc Fe–Mg alloys at core pressures and temperatures. We show that at core conditions, 5–10 atomic percent Mg stabilizes the bcc Fe both dynamically and thermodynamically. Our calculated density, elastic moduli, and sound velocities of bcc Fe–Mg alloys are consistent with those obtained from seismology, indicating that the bcc-structured Fe–Mg alloy is a possible model for the Earth's inner core.

scholarly journals Electronic correlations in Fe at Earth's inner core conditions: Effects of alloying with Ni

2015 ◽  
Vol 91 (24) ◽  
Author(s):  
O. Yu. Vekilova ◽  
L. V. Pourovskii ◽  
I. A. Abrikosov ◽  
S. I. Simak
Keyword(s):  
Inner Core ◽  
Electronic Correlations ◽  
Earth’S Inner Core ◽  
Core Conditions

scholarly journals Ni Doping: A Viable Route to Make Body-Centered-Cubic Fe Stable at Earth’s Inner Core

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 258
Author(s):  
Swastika Chatterjee ◽  
Sujoy Ghosh ◽  
Tanusri Saha-Dasgupta
Keyword(s):  
Inner Core ◽  
Computational Study ◽  
Stable Phase ◽  
Face Centered Cubic ◽  
Body Centered Cubic ◽  
Ni Doping ◽  
Earth’S Inner Core ◽  
Core Condition ◽  
Theoretical Evidence ◽  
The Stability

With the goal of answering the highly debated question of whether the presence of Ni at the Earth’s inner core can make body-centered cubic (bcc) Fe stable, we performed a computational study based on first-principles calculations on bcc, hexagonal closed packed (hcp), and face-centered cubic (fcc) structures of the Fe1−xNix alloys (x = 0, 0.0312, 0.042, 0.0625, 0.084, 0.125, 0.14, 0.175) at 200–364 GPa and investigated their relative stability. Our thorough study reveals that the stability of Ni-doped bcc Fe is crucially dependent on the nature of the distribution of Ni in the Fe matrix. We confirm this observation by considering several possible configurations for a given concentration of Ni doping. Our theoretical evidence suggests that Ni-doped bcc Fe could be a stable phase at the Earth’s inner core condition as compared to its hcp and fcc counterparts.

scholarly journals Two-phase mixture of iron–nickel–silicon alloys in the Earth’s inner core

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Daijo Ikuta ◽  
Eiji Ohtani ◽  
Naohisa Hirao
Keyword(s):  
Inner Core ◽  
Earth Model ◽  
Two Phase ◽  
Silicon Alloys ◽  
Hexagonal Close Packed ◽  
Iron Nickel ◽  
Earth’S Inner Core ◽  
Phase Mixture ◽  
Core Conditions ◽  
Nickel Silicon

AbstractThe Earth’s inner core comprises iron-nickel alloys with light elements. However, there is no clarity on the phase properties of these alloys. Here we show phase relations and equations of state of iron–nickel and iron–nickel–silicon alloys up to 186 gigapascals and 3090 kelvin. An ordered derivative of the body-centred cubic structure (B2) phase was observed in these alloys. Results show that nickel and silicon influence the stability field associated with the two-phase mixture of B2 and hexagonal close-packed phases under core conditions. The two-phase mixture can give the inner core density of the preliminary reference Earth model. The compressional wave velocity of the two-phase mixture under inner core conditions is consistent with that of the preliminary reference Earth model. Therefore, a mixture of B2 and hexagonal close-packed phases may exist in the inner core and accounts for the seismological properties of the inner core such as density and velocity deficits.

scholarly journals The elastic properties of hcp-Fe 1−x Si x at Earth's inner-core conditions

2016 ◽  
Vol 451 ◽  
pp. 89-96 ◽  
Author(s):  
Benjamí Martorell ◽  
Ian G. Wood ◽  
John Brodholt ◽  
Lidunka Vočadlo
Keyword(s):  
Elastic Properties ◽  
Inner Core ◽  
Earth’S Inner Core ◽  
Core Conditions

scholarly journals Electronic properties and magnetism of iron at the Earth's inner core conditions

2013 ◽  
Vol 87 (11) ◽  
Author(s):  
L. V. Pourovskii ◽  
T. Miyake ◽  
S. I. Simak ◽  
A. V. Ruban ◽  
L. Dubrovinsky ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Inner Core ◽  
Earth’S Inner Core ◽  
Core Conditions
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