Unveiling the effect of Ni on the formation and structure of Earth’s inner core
[1];
[2];
[4];
- Department of Physics, Xiamen University, Xiamen 361005, China, Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027, Department of Physics, Iowa State University, Ames, IA 50011
- Department of Physics, Iowa State University, Ames, IA 50011
- Center for Basic Research on Materials, National Institute for Materials Science, Ibaraki 305-0044, Japan
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027, Department of Earth and Environmental Sciences, Columbia University, New York, NY 10027, Lamont–Doherty Earth Observatory, Columbia University, Palisades, NY 10964, Data Science Institute, Columbia University, New York, NY 10027, Center for Computational Quantum Physics, Flatiron Institute, New York, NY 10010
Ni is the second most abundant element in the Earth’s core. Yet, its effects on the inner core’s structure and formation process are usually disregarded because of its electronic and size similarity with Fe. Using ab initio molecular dynamics simulations, we find that the bcc phase can spontaneously crystallize in liquid Ni at temperatures above Fe’s melting point at inner core pressures. The melting temperature of Ni is shown to be 700 to 800 K higher than that of Fe at 323 to 360 GPa. hcp, bcc, and liquid phase relations differ for Fe and Ni. Ni can be a bcc stabilizer for Fe at high temperatures and inner core pressures. A small amount of Ni can accelerate Fe’s crystallization at core pressures. These results suggest that Ni may substantially impact the structure and formation process of the solid inner core.
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- SC0019759
- OSTI ID:
- 2281740
- Journal Information:
- Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Vol. 121 Journal Issue: 4; ISSN 0027-8424
- Publisher:
- Proceedings of the National Academy of SciencesCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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