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Stability of body-c...
Stability of body-centered cubic iron-magnesium alloys in the Earth's inner core
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- Kádas, Krisztina (författare)
- Uppsala universitet,Institutionen för fysik och materialvetenskap
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- Vitos, Levente (författare)
- Uppsala universitet,KTH,Tillämpad materialfysik,Institutionen för fysik och materialvetenskap
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- Johansson, Börje (författare)
- Uppsala universitet,KTH,Tillämpad materialfysik,Institutionen för fysik och materialvetenskap
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- Ahuja, Rajeev (författare)
- Uppsala universitet,KTH,Materialvetenskap,Institutionen för fysik och materialvetenskap
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(creator_code:org_t)
- 2009-09-15
- 2009
- Engelska.
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 106:37, s. 15560-15562
- Relaterad länk:
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https://europepmc.or...
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https://urn.kb.se/re...
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https://doi.org/10.1...
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https://urn.kb.se/re...
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Abstract
Ämnesord
Stäng
- 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.
Ämnesord
- NATURVETENSKAP -- Fysik (hsv//swe)
- NATURAL SCIENCES -- Physical Sciences (hsv//eng)
Nyckelord
- ab initio calculations
- high pressure
- potential model
- approximation
- phase
- Physics
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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