地球中心核の物質と進化の解明

2015 Fiscal Year Annual Research Report

• Project/Area Number: 24000005
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: 廣瀬 敬 東京工業大学, 地球生命研究所, 教授 (50270921)
• Co-Investigator(Kenkyū-buntansha): 大石 泰生 公益財団法人高輝度光科学研究センター, 利用促進部門, 研究員 (20344400) ; ALFRED Baron 国立研究開発法人理化学研究所, 放射線光科学研究センター, 准主任研究員 (90442920)
• Project Period (FY): 2013 – 2015
• Keywords: 地球深部 / コア / 下部マントル / 高圧 / 放射光

Outline of Annual Research Achievements

コアの高圧高温下における液体の鉄-水素合金につき、第一原理計算によって密度と速度を明らかにした。その結果、水素を1.0wt.%含む液体鉄は密度と速度ともに、地震波観測と整合的であることがわかった。さらに、超高圧下での鉄-シリコン-水素合金の密度測定を放射光施設SPring-8で行い、これもコアの観測値をよく説明することを明らかにして、水素がコアの重要な軽元素であることを示した。一方、鉄の電気抵抗率を、レーザー加熱式ダイヤモンドアンビルセルを用いた静的高圧実験としては初めて、コアの超高圧高温下で実測することに成功し、熱伝導率を得た。電気抵抗率が高温で飽和することを確認し、コアの熱伝導率が従来の値の3倍程度高いことを明らかにした。また、エックス線非弾性散乱測定によって液体鉄合金の縦波速度を70万気圧の超高圧下まで決定することに、これも静的高圧実験としては初めて成功した。その結果、炭素が含まれることによって液体鉄の速度が上がること、鉄-炭素合金ではコアの密度と速度を同時に説明できないこと、を明らかにした。マントル深部の圧力まで、FeO-Si02の2成分系の融解実験を行い、共融点温度はFeO端成分の融点に近いこと、つまり共融点組成はFeO端成分にとても近いことがわかった。このことはマントル最深部でシリケイトメルトの分別結晶作用が起こると組成はFeOに近づいていき、少なくともおよそ3500度まで液体のまま存在することを意味している。

Research Products

• [Int'l Joint Research] Geophysical Laboratory/University of California, Berkeley/University of Minnesota(米国)
  • Country Name: U.S.A.
  • Counterpart Institution: Geophysical Laboratory/University of California, Berkeley/University of Minnesota
• [Int'l Joint Research] Université Pierre et Marie Curie/Ecole Normale Supeé-rieure de Lyon(フランス)
  • Country Name: FRANCE
  • Counterpart Institution: Université Pierre et Marie Curie/Ecole Normale Supeé-rieure de Lyon
• [Int'l Joint Research] Universite de Liège(ベルギー)
  • Country Name: BELGIUM
  • Counterpart Institution: Universite de Liège
• [Int'l Joint Research] The University of Edingurgh(英国)
  • Country Name: UNITED KINGDOM
  • Counterpart Institution: The University of Edingurgh
• [Journal Article] Phase transition and melting in the deep lower mantle (2016)
  • Author(s): Hirose, K.
  • Journal Title: AGU monograph "Deep Earth : Physics and Chemistry of the Lower Mantle and Core" Pages: 209-224
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Melting in the Fe0-Si02 system to deep lower mantle pressures : implications for subducted Banded Iron Formations (2016)
  • Author(s): Kato, C., Hirose, K., Nomura, R., Miyake, A., Ohishi, Y.
  • Journal Title: Earth and Planetary Science Letters, Volume: 440 Pages: 56-61
  • DOI: 10.1016/j.epsl.2016.02.011
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Experimental determination of the electrical resistivity of iron at Earth's core conditions, (2016)
  • Author(s): Ohta, K., Kuwayama, Y., Hirose, K., Shimizu, K., Ohishi, Y.
  • Journal Title: Nature
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Post-stishovite transition in hydrous aluminous Si02 (2016)
  • Author(s): Umemoto, K., Kawamura, K., Hirose, K., Wentzcovitch, R. M.
  • Journal Title: Physics of the Earth and Planetary Interiors Volume: 255 Pages: 18-26
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Compression of Fe-Si-H alloys to core pressures (2016)
  • Author(s): Tagawa, S., Ohta, K., Hirose, K., Kato, C., Ohishi, Y
  • Journal Title: Geophysical Research Letters Volume: 43
  • DOI: 10.1002/2016GL068848
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Constraints on Earth's inner core composition inferred from measurements of the sound velocity of hcp-iron in extreme conditions. (2016)
  • Author(s): T. Sakamaki, E. Ohtani, H. Fukui, S. Kamada, S. Takahashi, T. Sakairi, A. Takahata, T. Sakai, S. Tsutsui, D. Ishikawa, R. Shiraishi, Y. Seto, T. Tsuchiya, and A. Q. R. Baron
  • Journal Title: Sci. Adv. Volume: 2
  • URL: http://advances.sciencemag.ort/content/2/2/e1500802.abstract
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Low-energy optical phonon modes in the cage compound LaRu2Zn20 (2016)
  • Author(s): K. Wakiya, T. Onimaru, S. Tsutsui, T. Hasegawa, K. T. Matsumoto, N. Nagasawa, A. Q. R. Baron, N. Ogita, M. Udagawa, and T. Takabatake
  • Journal Title: Phys. Rev. B Volume: 93 Pages: 64105
  • DOI: 10.1103/PhysPevB.93.064105
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Effect of magnetism on lattice dynamics in SrFe2As2 using high-resolution inelastic x-ray scattering. (2016)
  • Author(s): N. Murai, T. Fukuda, T. Kobayashi, M. Nakajima, H. Uchiyama, D. Ishikawa, S. Tsutsui, H. Nakamura, M. Machida, S. Miyasaka, S. Tajima, and A. Q. R. Baron
  • Journal Title: Phys. Rev. B Volume: 93 Pages: 20301
  • DOI: 10.1103/PhysRevB.93.020301
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Mineralogy of the deep mantle - the post-perovskite phase and its geophysical significance (2015)
  • Author(s): Hirose, K., Wentzcovitch, R., Yuen, D., Lay, T.
  • Journal Title: Gerald Schubert (editor- in-chief) Treatise on Geophysics 2nd edition Volume: 2 Pages: 85-115
  • DOI: 10.1016/B978-0-444-53802-4.00054-3
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Electrical resistivity and thermal conductivity of hcp Fe-Ni alloys under high pressure : Implications for thermal convection in the Earth's core (2015)
  • Author(s): Gomi, H., Hirose, K.
  • Journal Title: Physics of the Earth and Planetary Interiors Volume: 247 Pages: 2-10
  • DOI: 10.1016/j.pepi.2015.04.003,2015.
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Stability and compressibility of a new iron-nitride β-Fe7N3 to core pressures (2015)
  • Author(s): Minobe, S., Nakajima, Y., Hirose, K., Ohishi, Y.
  • Journal Title: Geophysical Research Letters Volume: 42
  • DOI: 10.1002/2015GL064496,2015.
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Temperature dependence of the velocity-density relation for liquid metals under high pressure : implications for the Earth's outer core (2015)
  • Author(s): Komabayashi, T., Kato, J., Hirose, K., Tsutsui, S., Imada, S, Nakajima, Y., Baron, A. Q. R.
  • Journal Title: American Mineralogist Volume: 100 Pages: 2602-2609
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Nature of the volume isotope effect in ice, (2015)
  • Author(s): Umemoto, K., Sugimura, E., de Gironcoli, S., Nakajima, Y., Hirose, K., Ohishi, Y., Wentzcovitch, R. M.
  • Journal Title: Physical Review Letters, Volume: 115 Pages: 173,005
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Liquid iron-hydrogen alloys at outer core conditions by first-principles calculations (2015)
  • Author(s): Umemoto, K., Hirose, K.
  • Journal Title: Geophysical Research Letters Volume: 42 Pages: 7513-7520
  • DOI: 10.1002/2015GL065899
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Carbon depleted outer core revealed by sound velocity measurements of liquid Fe-C alloy (2015)
  • Author(s): Nakajima, Y., Imada, S., Hirose, K., Komabayashi, T., Ozawa, H., Tateno, S., Tsutsui, S., Kuwayama, Y., Baron, A. Q. R.
  • Journal Title: Nature Communications Volume: 6
  • DOI: 10.1038/ncomms9942
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Heating of Li in Hydrogen : Possible Synthesis of LiHx (2015)
  • Author(s): K. Kuno, T. Matsuoka, T. Nakagawa, N. Hirao, Y. Ohishi, K. Shimizu, K. Takahama, K. Ohta, M. Sakata, Y. Nakamoto, T. Kume, and S. Sasaki
  • Journal Title: High Pressure Research Volume: 133 Issue: 1 Pages: 16-21
  • DOI: 10.1063/1.4914844
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] High-Presure Generation using Double Stage Micro-Paired Diamond Anvils Shaped by Focused Ion Beam (2015)
  • Author(s): T. Sakai, T. Yagi, H. Ohfuji, T. Irifune, Y. Ohishi, N. Hirao, Y. Suzuki, Y. Kuroida, T. Asakawa, and T. Kanemura
  • Journal Title: Review of Scientific Instruments Volume: 86 Pages: 33905
  • DOI: 10.1063/1.4914844
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Time-resolved X-ray Diffraction and Raman Studies of the Phase Transition mechanisms of Methane Hydrate (2015)
  • Author(s): H. Hirai, H. Kadobayashi, N. Hirao, Y. Ohishi, Y. Tamamoto, and S. Nakano
  • Journal Title: The Journal of Chemcal Physics Volume: 142 Pages: 24707
  • DOI: 10.1063/1.4905482
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] The Structure of Fe-Si Alloy in Earth's Inner Core (2015)
  • Author(s): S. Tateno, Y. Kuwayama, K. Hirose, and Y. Ohishi
  • Journal Title: Earth and Planetary Science Letters Volume: 418 Pages: e1500059
  • DOI: 10.1016/j.epsl.2015.02.008
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Nature of the Volume Isotope Effect in ice (2015)
  • Author(s): K. Umemoto, E. Sugimura, S. Gironcoli, Y. Nakajima, K. Hirose, Y. Ohishi, and R. M. Wentzkovitch
  • Journal Title: Physical Review Letters Volume: 115-7 Pages: 173005
  • DOI: 10.1103/PhysRevLett.115.173005
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] High pressure-low temperature phase diagram of barium : Simplicity versus complexity (2015)
  • Author(s): S. Desgreniers, J. S. Tse, T. Matsuoka, Y. Ohishi, Q. Li, and Y. Ma
  • Journal Title: Applied Physics Letters Volume: 107 Pages: 221908
  • DOI: 10.1063/1.4936849
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Phase boundary of hot dense fluid hydrogen (2015)
  • Author(s): K. Ohta, K. Ichimaru, M. Einaga, S. Kawaguchi, K. Shimizu, T. Matsuoka, N. Hirao, and Y. Ohishi
  • Journal Title: Scientific Reports Volume: 5 Pages: 16560
  • DOI: 10.1038/srep16560
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Mixing unmixables : unexpected formation of Li-Cs alloys at low pressure (2015)
  • Author(s): S. Desgreniers, J. S. Tse, T. Matsuoka, Y. Ohishi, and J. J. Tse
  • Journal Title: Science Advances Volume: 1 Pages: e1500669
  • DOI: 10.1126/sciadv.1500669
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Pressure-induced unusual metallic state in EuNi03 (2015)
  • Author(s): H. Kobayashi, S. Ikeda, Y. Yoda, N. Hirao, Y. Ohishi, J. Alonso, M. J. Martonez-Lope, R. Lengsforf, D. I. Khomskii, and M. M. Abd-Elmequid
  • Journal Title: Physical Review B Volume: 91.19 Pages: 195148
  • DOI: 10.1103/PhysRevB.91.195148
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Inelastic x-ray scattering studies on dynamic structure factor of polymeric liquid Se under pressure (2015)
  • Author(s): M. Inui, Y. Kajihara, K. Kimura, K. Matsuda, K. Ohara, S. Tsutsui, D. Ishikawa, and A. Q. Baron
  • Journal Title: AIP Conf. Proc. Volume: 1673 Pages: 2602
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Signature of a polyamorphic transition in the THz spectrum of vitreous Ge02 (2015)
  • Author(s): A. Cunsolo, Y. Li, C. N. Kodituwakku, S. Wang, D. Antonangeli, F. Bencivenga, A. Battistoni, R. Verbeni, S. Tsutsui, A. Q. R. Baron, H-K. Mao, D Bolmatov, and Y. Q. Cai.
  • Journal Title: Scientific Reports Volume: 5 Pages: 14996
  • DOI: 10.1038/srep14996
  • URL: http://www.nature.com/articles/srep14996#auth-1
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] High-Resolution Inelastic X-Ray Scattering I : Context, Spectrometers, Samples, and Superconductors (2015)
  • Author(s): Alfred Q. R. Baron
  • Journal Title: Synchrotron Light Sources and Free-Electron Lasers Pages: 1-68
  • DOI: 10.1007/978-3-319-04507-8_41-1
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Anomalous dispersion of the acoustic mode in liquid Bi (2015)
  • Author(s): M. Inui, Y. Kajihara, S. Munejiri, S. Hosokawa, A. Chiba, K. Ohara, S. Tsutsui and A. Q. R. Baron
  • Journal Title: Physical Review B Volume: 95 Pages: 54206
  • DOI: 10.1103/PhysRevB.92.054206
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Transverse Excitations in liquid Fe, Cu and Zn. (2015)
  • Author(s): S. Hosokawa, M. Inui, Y. Kajihara, S. Tsutsui and A. Q. R. Baron
  • Journal Title: Journal of Physics : Condensed Matter, Volume: 27 Pages: 194104
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Sound velocity measurement by inelastic X-ray scattering at high pressure and temperature by resistive heating diamond anvil cell (2015)
  • Author(s): E. Ohtani, K. Mibe, T. Sakamaki, S. Kamada, S. Takahashi, Y. Shibazaki, H. Fukui, S. Tsutsui, A. Q. R. Baron
  • Journal Title: Russian Geology and Geophysics Volume: 56 Pages: 190-5
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Inelastic x-ray scattering with 0.75 meV resolution at 25.7 keV using a temperature gradient analyzer. (2015)
  • Author(s): D. Ishikawa, D. S. Ellis, H. Uchiyama and A. Q. R. Baron
  • Journal Title: Journal of Synchrotron Radiation, Volume: 22 Pages: 42,438
  • DOI: 10.1107/S1600577514021006.
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] High-Resolution Inelastic X-Ray Scattering II : Scattering Theory, Harmonic Phonons, and Calculations (2015)
  • Author(s): Alfred Q. R. Baron
  • Journal Title: Synchrotron Light Sources and Free-Electron Lasers Pages: 1-32
  • DOI: 10.1007/978-3-319-04507-8_52-1
  • Peer Reviewed / Int'l Joint Research
• [Presentation] Phonons and Electrons in Superconductors via non-resonant inelastic x-ray scattering (2016)
  • Author(s): Alfred Q. R. Baron
  • Organizer: 17th Crossroads Workshop
  • Place of Presentation: Tokai, Japan
  • Year and Date: 2016-01-18
  • Int'l Joint Research
• [Presentation] Multi-Photon, 14.4 KeV, Nuclear Excitation using the SACLA X-Ray Laser (2016)
  • Author(s): Alfred Q. R. Baron
  • Organizer: Winter Colloquium on the Physics of Quantum Electronics (PQE-2016)
  • Place of Presentation: Snowbird, Utah, USA
  • Year and Date: 2016-01-08
  • Int'l Joint Research
• [Presentation] Crystallization in Earth's core after high-temperature core formation (2015)
  • Author(s): Kei Hirose
  • Organizer: 2015 AGU Fall Meeting
  • Place of Presentation: サンフランシスコ、USA
  • Year and Date: 2015-12-12 – 2015-12-14
  • Int'l Joint Research
• [Presentation] Phonons and Electrons in YBa2Cu306+y via non-resonant inelastic x-ray scattering (2015)
  • Author(s): Alfred Q. R. Baron
  • Organizer: 9th International Conference on Inelastic X-Ray Scattering (IXS 2015)
  • Place of Presentation: Hisnchu, Taiwan
  • Year and Date: 2015-11-22
  • Int'l Joint Research / Invited
• [Presentation] Crystallization of Si02 in Earth's core after high-temperature core formation (2015)
  • Author(s): Kei Hirose
  • Organizer: The Earth's Mantle and Core : Structure, Composition, Evolution
  • Place of Presentation: 道後プリンスホテル(愛媛県、松山市)
  • Year and Date: 2015-11-04 – 2015-11-06
  • Int'l Joint Research
• [Presentation] Overview of the dynamo evolution problem and the heat “paradox (2015)
  • Author(s): Kei Hirose
  • Organizer: Geophysical & Geochemical Constraints on Early Planetary Dynamos
  • Place of Presentation: 山梨県南都留郡
  • Year and Date: 2015-09-16 – 2015-09-17
  • Int'l Joint Research
• [Presentation] High-Pressure Applications by using X-ray Micro-Beam at SPring-8 (2015)
  • Author(s): Y. Ohishi, N. Hirao, Y. Mori, K. Shimizu and Kei Hirose
  • Organizer: Joint AIRAPT-25 & EHPRG-53 International Conference On High Pressure Science And Technology
  • Place of Presentation: Madrid, Spain
  • Year and Date: 2015-09-03
  • Int'l Joint Research
• [Presentation] Pushing the limits of non-resonant IXS to Investigate Cuprate Superconductors (2015)
  • Author(s): Alfred Q. R. Baron
  • Organizer: Gordon Conference on X-Ray Science
  • Place of Presentation: Washington, USA
  • Year and Date: 2015-07-27
  • Int'l Joint Research / Invited
• [Presentation] Melting experiments in a diamond-anvil cell combined with ex-situ textual and chemical characterizations by FIB/SEM/TEM (2015)
  • Author(s): Kei Hirose
  • Organizer: New Frontier in Studying Chemistry under Extreme Conditions
  • Place of Presentation: 中国、上海市
  • Year and Date: 2015-05-19 – 2015-05-23
  • Int'l Joint Research / Invited
• [Book] できたての地球-生命誕生の条件- (2015)
  • Author(s): 廣瀬敬
  • Total Pages: 126
  • Publisher: 岩波書店