Theoretical study of Earth/planet-forming materials in Earth's inner core and deep inside of exoplanets
| Project/Area Number |
17K05627
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Solid earth and planetary physics
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2019: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2018: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2017: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
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| Keywords | 第一原理計算 / 高圧相転移 / スーパーアース / 外核 / 液体鉄合金 / ポストポストペロブスカイト / 低圧アナログ物質 / 超高圧 / 相転移 / 地球外核 / 地球惑星構成物質 / 超高圧物性 / 超高圧相転移 / 地球惑星物質 / 固体地球物理学 / 計算物理 / 高圧力物性 |
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| Outline of Final Research Achievements |
・We performed first-principles molecular dynamics simulations on liquid iron alloys with hydrogen, oxygen, carbon, sulfur, and silicon. By comparing the computational results with seismic observation, we have constrained the kind and amount of the light elements in the outer core of the Earth. Then, we have determined the chemical composition of the outer core which shows the best coincidence with the seismic observation.
・For the Mg-Si-O system, we have predicted the post-post-perovskite transitions which are expected to occur in deep interiors of super-Earths. Under ultrahigh pressures, MgSiO3 PPV should undergo the three-stage dissociations. When MgSiO3 PPV coexists with MgO or SiO2, they should recombine. In addition, we have proposed that Mg-Ge-O and Na-Mg-F systems can be used as useful low-pressure analogs of the Mg-Si-O system.
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| Academic Significance and Societal Importance of the Research Achievements |
・地球外核の化学組成は、地球物理学において長年未解決であり続ける問題である。本研究はこの問題の解決に向けて大きな一歩となり、さらに今後どのような研究が必要なのかの指針を示した。
・2019年のノーベル物理学賞の対象になったことからも明らかな通り、近年数多く見つかっている系外惑星への注目は非常に高まっている。地球型系外惑星（スーパーアース）の内部構造を明らかにする上で、本研究が予言した相転移は最も基本的な情報の一つとなる。
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Report
(4 results)
Research Products
(26 results)
