Updated on 2022/04/13

写真a

 
MASHINO Idumi
 
Organization
Institute for Planetary Materials Special-Appointment Assistant Professor
Position
Special-Appointment Assistant Professor
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Degree

  • 博士(理学) ( 東北大学 )

  • 修士(理学) ( 東北大学 )

Research History

  • Okayama University   Institute for Planetary Materials

    2020.6

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  • ETH Zurich

    2019.1 - 2020.5

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  • The University of Tokyo   理学系研究科

    2017.4 - 2018.12

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  • Tohoku University

    2015.4 - 2017.3

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Papers

  • Experimental evidence for silica-enriched Earth's lower mantle with ferrous iron dominant bridgmanite. Reviewed International journal

    Izumi Mashino, Motohiko Murakami, Nobuyoshi Miyajima, Sylvain Petitgirard

    Proceedings of the National Academy of Sciences of the United States of America   117 ( 45 )   27899 - 27905   2020.11

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    Language:English   Publishing type:Research paper (scientific journal)  

    Determination of the chemical composition of the Earth's mantle is of prime importance to understand the evolution, dynamics, and origin of the Earth. However, there is a lack of experimental data on sound velocity of iron-bearing Bridgmanite (Brd) under relevant high-pressure conditions of the whole mantle, which prevents constraints on the mineralogical model of the lower mantle. To uncover these issues, we have conducted sound-velocity measurement of iron-bearing Brd in a diamond-anvil cell (DAC) up to 124 GPa using Brillouin scattering spectroscopy. Here we show that the sound velocities of iron-bearing Brd throughout the whole pressure range of lower mantle exhibit an apparent linear reduction with the iron content. Our data fit remarkably with the seismic structure throughout the lower mantle with Fe2+-enriched Brd, indicating that the greater part of the lower mantle could be occupied by Fe2+-enriched Brd. Our lower-mantle model shows a distinctive Si-enriched composition with Mg/Si of 1.14 relative to the upper mantle (Mg/Si = 1.25), which implies that the mantle convection has been inefficient enough to chemically homogenize the Earth's whole mantle.

    DOI: 10.1073/pnas.1917096117

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  • Melting experiments on the Fe–C binary system up to 255 GPa: Constraints on the carbon content in the Earth's core Reviewed

    Izumi Mashino, Francesca Miozzi, Kei Hirose, Guillaume Morard, Ryosuke Sinmyo

    Earth and Planetary Science Letters   515   135 - 144   2019.6

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    © 2019 Elsevier B.V. Phase relations, including the eutectic liquid composition in the Fe–C binary system, remain unclear under the core pressure range, which makes estimating the carbon budget in the Earth's core difficult. To explore this issue, we have conducted melting and subsolidus experiments on Fe–C alloys in a diamond-anvil cell up to 255 GPa. Textural and compositional characterizations of quenched samples show that carbon concentration in the eutectic liquid slightly decreases with increasing pressure and is about 3 wt.% at the inner core boundary (ICB) pressure. The solubility of carbon in solid Fe is found to be almost constant at ∼1.0 wt.%. In situ X-ray diffraction data indicate that Fe forms eutectic melting with Fe 3 C to 203 GPa and with Fe 7 C 3 at 255 GPa. Previous studies on liquid Fe–C alloys suggested that the density of the outer core is explained by liquid Fe containing 1.8 to 4.2 wt.% C. If the liquid core includes <3 wt.% C as a single light element, hexagonal close-packed (hcp) Fe crystallizes at the ICB. However, the carbon content in such solid Fe is ≤1 wt.%, less than that required to account for the inner core density deficit from pure iron. When the outer core includes ≥3 wt.% C, it forms Fe 7 C 3 at the ICB, whose density is too small for the inner core. Carbon is therefore not a primary light element in the core. Nevertheless, the outer core liquid can be Fe–C–Si, Fe–C–S, or Fe–C–H. Such core liquid crystallizes solid Fe with light elements including less than 1 wt.% C, which may explain the density and the sound velocities observed in the inner core.

    DOI: 10.1016/j.epsl.2019.03.020

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  • Sound velocities of δ-AlOOH up to core-mantle boundary pressures with implications for the seismic anomalies in the deep mantle Reviewed

    Izumi Mashino, Motohiko Murakami, Eiji Ohtani

    Journal of Geophysical Research: Solid Earth   121 ( 2 )   595 - 609   2016.2

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:AMER GEOPHYSICAL UNION  

    ©2016. American Geophysical Union. All Rights Reserved. Recent studies show that δ-AlOOH is stable up to the base of the mantle. This phase is, therefore, a possible carrier and host of water in the deep mantle. To uncover the physical properties of δ-AlOOH under deep mantle pressure conditions, we have conducted high-pressure acoustic wave velocity measurements of δ-AlOOH by using Brillouin spectroscopy combined with high-pressure Raman spectroscopic measurements in a diamond anvil cell up to pressures of 134 GPa. There is a precipitous increase by ∼14% in the acoustic velocities of δ-AlOOH from 6 to 15 GPa, which suggests that pressure-induced O-H bond symmetrization occurs in this pressure range. The best fit values for the high-pressure form of δ-AlOOH of K0 = 190 (2) (GPa), G0 = 160.0 (9) (GPa), (∂K/∂P)0 = K0′ = 3.7 (1), and (∂G/∂P)0 = G0′ = 1.32 (1) indicate that δ-AlOOH has a 20-30% higher VS value compared to those of the major constituent minerals in the mantle transition zone, such as wadsleyite, ringwoodite, and majorite. On the other hand, the VS of δ-AlOOH is ∼7% lower than that of Mg-bridgmanite under lowermost mantle pressure conditions because of the significantly lower value of the pressure derivative of the shear modulus. By comparing our results with seismic observations, we can infer that δ-AlOOH could be one of the potential causes of a positive VS anomaly observed at ∼600 km depth beneath the Korean peninsula and a negative VS jump near 2800 km depth near the northern margin of the large low-shear-velocity province beneath the Pacific.

    DOI: 10.1002/2015JB012477

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  • A cylindrical SiC heater for an externally heated diamond anvil cell to 1500 K

    Yoshiyuki Okuda, Seiji Kimura, Kenji Ohta, Yohan Park, Tatsuya Wakamatsu, Izumi Mashino, Kei Hirose

    Review of Scientific Instruments   92 ( 1 )   2021.1

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    © 2021 Author(s). Semiconductor-based heaters for diamond anvil cells (DACs) have advantages over metal wire heaters in terms of repeated use and the ability to reach higher temperatures. We introduce a cylindrical SiC heater for an externally heated DAC (EHDAC) that works satisfactorily at temperatures up to 1500 K and pressures around 90 GPa. The heater is reusable and inexpensive, and only slight modifications to the DAC are required to fit the heater. Experiments on melting of NaCl and gold are conducted at ambient pressure to test the temperature accuracy of the EHDAC system, and resistance measurements on iodine at high pressures and temperatures are performed to assess the heater assembly. These test runs show that a uniform and accurate temperature can be maintained by the EHDAC assembly, which has potential applications to a variety of transport property measurements.

    DOI: 10.1063/5.0036551

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  • Stability of Hydrous Minerals and Water Reservoirs in the Deep Earth Interior Reviewed

    Eiji Ohtani, Yohei Amaike, Seiji Kamada, Itaru Ohira, Izumi Mashino

    Deep Earth: Physics and Chemistry of the Lower Mantle and Core   265 - 275   2015.1

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    Publishing type:Part of collection (book)  

    © 2016 American Geophysical Union. All rights reserved. This chapter summarizes water storage capacities in hydrous phases and nominally anhydrous minerals in the deep mantle. Water has significant effects on the phase boundaries of the phase transformations of the mantle minerals and can explain some topography of the 410 and 660km seismic discontinuities. There are several electrical conductivity studies of wadsleyite and ringwoodite to determine the water content in the mantle transition zone, since electrical conductivity is very sensitive to the hydrogen contents in minerals. The mantle transition zone has a high water storage capacity due to high water solubility in its major constituents, wadsleyite and ringwoodite, and stores significant amount of water at least locally. Hydrous phase H, MgSiO2(OH)2, and its solid solution with isostructural phase δ-AlOOH store water in the lower mantle, and they transport water into the bottom of the lower mantle by slab subduction.

    DOI: 10.1002/9781118992487.ch21

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  • Chemistry and mineralogy of earth's mantle. the spin state of iron in Fe3+-bearing Mg-perovskite and its crystal chemistry at high pressure Reviewed

    Izumi Mashino, Eiji Ohtani, Naohisa Hirao, Takaya Mitsui, Ryo Masuda, Makoto Seto, Takeshi Sakai, Suguru Takahashi, Satoshi Nakano

    American Mineralogist   99 ( 8-9 )   1555 - 1561   2014.8

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:MINERALOGICAL SOC AMER  

    © 2014 by Walter de Gruyter Berlin/Boston. Valence, spin states, and crystallographic sites of Fe in (Mg,Fe)SiO3perovskite were investigated using energy-domain 57Fe-synchrotron Mössbauer spectroscopy and powder X-ray diffraction up to 86 GPa. The volumes of Fe3+-bearing perovskite in this study are slightly smaller than those of Mg endmember perovskite. Our Mössbauer data suggest that Fe3+prefers A sites coupled with Mg vacancies, which is consistent with previous data at ambient conditions. Fe3+in the A site remains in a high-spin state up to 86 GPa, and some fraction of the A site is occupied by Fe2+at pressures above 30 GPa. Fe2+in the A sites is also in a high-spin state up to 86 GPa. The coupled substitution from Mg2+to a highspin state of Fe3+and Mg2+vacancy would make the volume of perovskite smaller than that of Mg end-member perovskite. If the lower mantle is saturated in silica, perovskite containing high-spin Fe3+in A site has a higher density. Such silica oversaturated regions could sink by the density difference.

    DOI: 10.2138/am.2014.4659

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  • Equation of state of pure iron and Fe<inf>0.9</inf>Ni<inf>0.1</inf> alloy up to 3Mbar Reviewed

    Takeshi Sakai, Suguru Takahashi, Naoya Nishitani, Izumi Mashino, Eiji Ohtani, Naohisa Hirao

    Physics of the Earth and Planetary Interiors   228   114 - 126   2014.3

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

    Pure iron and Fe0.9Ni0.1 alloy were compressed to a pressure of 279GPa and 272GPa, respectively. The compression data sets were fitted using the third order Birch-Murnaghan equation of state based on six different pressure scales. Our result shows the nickel increase the density and the c/a ratio, decrease the bulk modulus. The high temperature data obtained the thermal equation of state parameters. At high temperature, although the nickel effect on density slightly decrease due to the a little larger thermal expansion, the bulk modulus difference increase to 7.3-7.8% at 329GPa and 5000K. Nickel effects on elasticity might be important at multimegabar pressure and especially high temperature such as the inner core condition. The core density deficit was estimated to be 3.5(1)-5.3(1)% for pure iron and 4.7(1)-6.5(2)% for Fe0.9Ni0.1 alloy if the temperature at the inner core boundary is 5000K. © 2014 Elsevier B.V.

    DOI: 10.1016/j.pepi.2013.12.010

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MISC

  • Experimental evidence for silica-enriched Earth's lower mantle with ferrous iron dominant bridgmanite Invited

    I. Mashino, M. Murakami, N. Miyajima, S. Petitgirard

    Bayerisches Forschungsinstitut für Experimentelle Geochemie und Geophysik Universität Bayreuth, ANNUAL REPORT 2020   28 - 29   2021

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    Language:English   Publishing type:Rapid communication, short report, research note, etc. (bulletin of university, research institution)  

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  • Experimental Mineral Physics, Institute of Geochemistry and Petrology, Department of Earth Sciences, ETH Zurich

    MASHINO Izumi

    The Review of High Pressure Science and Technology   29 ( 3 )   217 - 218   2019

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    Language:Japanese   Publisher:The Japan Society of High Pressure Science and Technology  

    DOI: 10.4131/jshpreview.29.217

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  • O9-09 Brillouim散乱法を用いた地球核マントル境界圧力条件までのδ-AlOOH相の音速測定と地球・火星内部への適用(口頭発表セッション9 月・内部構造,口頭発表)

    増野 いづみ, 村上 元彦, 大谷 栄治

    日本惑星科学会秋期講演会予稿集   2014   "O9 - 09"   2014.9

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    Language:Japanese   Publisher:日本惑星科学会  

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  • Equation of state of Fe3+-bearing Mg-perovskite in lower mantle and effects on the spin transition of iron.

    Mashino Izumi, Ohtani Eiji, Sakai Takeshi, Hamada Maki, Nakano Satoshi, Akasaka Masahide, Hirao Naohisa

    Abstracts for Annual Meeting of Japan Association of Mineralogical Sciences   2012 ( 0 )   136 - 136   2012

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    Language:Japanese   Publisher:Japan Association of Mineralogical Sciences  

    In order to study the effects of spin transitions on the equation of state of Mg-perovskite, we performed in situ synchrotron X ray powder diffraction on Fe3+-bearing Mg-perovskite using NaCl or Ne pressure medium. The sample was annealed in measurements using Ne pressure medium, whereas it was not annealed in the runs using NaCl pressure medium. The unit cell volumes of runs using Ne pressure medium are smaller than those using NaCl pressure medium. The difference in compression curves may be caused by the difference in stress conditions and/or Fe2+/Fe3+ ratios of the samples during the experiments.

    DOI: 10.14824/jakoka.2012.0_136

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Presentations

  • Melting experiments on the Fe–C binary system up to 255 GPa: Constraints on the carbon content in the Earth’s core

    Mashino I., Miozzi F., Hirose K., Morard G., Sinmyo R.

    AGU Fall meeting 

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    Event date: 2018.12

    Language:English   Presentation type:Oral presentation (general)  

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  • Mineralogical model of the lower mantle inferred from high pressure sound velocity data Invited

    Mashino I ., Murakami M., Miyajima N., Petitgirard S., Frost D

    IAG-IASPEI 2017 

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    Event date: 2017.7 - 2017.8

    Language:English   Presentation type:Oral presentation (invited, special)  

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  • Sound Velocities of δ-AlOOH up to CMB Pressures with Implications for the Seismic Anomalies in Deep Mantle

    Mashino I., Murakami M., Ohtani E.

    Goldschmidt2016  2016.6 

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  • Sound velocity of δ-AlOOH up to core-mantle boundary pressures: Implications for the seismic anomalies induced by hydrated sediment in subducting slabs

    Mashino I., Murakami M., Ohtani E.

    AGU Fall meeting  2014.12 

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    Language:English   Presentation type:Oral presentation (general)  

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  • Experimental evidence for Si-enriched Earth’s lower mantle with ferrous iron dominant bridgmanite

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    Event date: 2021.7.26 - 2021.7.30

    Language:English   Presentation type:Oral presentation (general)  

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  • Elasticity of hydrous phase δ-AlOOH up to core-mantle boundary pressures: Implications for the seismic anomalies induced by hydrated sediment in subducting slabs

    Mashino I., Murakami M., Ohtani E.

    Deep Carbon Observatory Summer School 2014 

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    Event date: 2014.7.13 - 2014.7.18

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  • Elastic properties of delta-AlOOH under high-pressure: Implications for high Vs anomaly in the mantle transition zone

    Mashino I., Murakami M., Ohtani E.

    Japan Geoscience Union Meeting 2014 

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    Event date: 2014.4 - 2014.5

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  • 高温高圧下におけるMg(OH)2の安定領域

    増田滉己, 増野いづみ, 廣瀬敬

    日本地球惑星科学連合2018年大会  2018.5 

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  • 地球コアの解明に向けて

    廣瀬敬, 増野いづみ, 新名良介, 大石泰生

    SPring-8シンポジウム2017  2017.9 

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    Presentation type:Symposium, workshop panel (nominated)  

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  • Sound velocities of δ-AlOOH up to lowermost mantle pressures; Implications for the seismic anomalies in deep mantle Invited

    Mashino I.

    HPSTAR  2017.2 

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  • Sound Velocities of δ-AlOOH up to CMB Pressures with Implications for the Seismic Anomalies in Deep Mantle

    Mashino I., Murakami M., Ohtani E.

    Tohoku Forum for Creativity, Earth and Planetary Dynamics, International Workshop:New Challenges in Volatile Cycling in the Deep Earth  2016.7 

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  • Sound velocities of delta-AlOOH up to lowermost mantle presuure; Implications for the seismic anomalies in deep mantle

    Mashino I., Murakami M., Ohtani E.

    Japan Geoscience Union Meeting 2016  2016.5 

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  • 核マントル境界圧力条件までのδ-AlOOH相の音速測定;沈み込むスラブの含水堆積岩層による地震波不連続への影響

    増野いづみ, 村上元彦, 大谷栄治

    第55回高圧討論会  2014.11 

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  • 高温高圧下における含水H相-δ相固溶体(MgSi,Al2)O2(OH)2の安定領域と下部マントルの水

    大谷栄治, 天池洋平, 鎌田誠司, 坂巻竜也, 増野いづみ, 村上元彦, 鈴木昭夫, 平尾直久

    第55回高圧討論会  2014.11 

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  • Sound velocities of MgGeO3 gel at high pressure: Implication for structural changes in mgSiO3 melt

    Kawadai T., Murakami M., Ohtani E., Mashino I.

    International Symposium “Advances in High Pressure Research: Breaking scales and horizons”  2014.9 

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    Presentation type:Symposium, workshop panel (nominated)  

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  • Brillouin散乱法を用いた地球核マントル境界圧力条件までのδ-AlOOH相の音速測定と地球・火星内部への適用

    増野いづみ, 村上元彦, 大谷栄治

    日本惑星科学会  2014.9 

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  • Elasticity of δ-AlOOH under high pressure: Implications for positive Vs anomaly at 600 km depth

    Mashino I., Murakami M., Ohtani E.

    11th International Workshop on WATER DYNAMICS, Deep Carbon Cycle  2014.3 

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  • Equations of state of iron and Fe0.9Ni0.1 alloy.

    Sakai T., Takahashi S., Nishitani N., Mashino I., Ohtani E., Hirao N.

    Workshop on Elasticity and Iron  2014.2 

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  • Stability and melting relations of Fe3C up to 3 Mbar: Implication for the carbon in the Earth’s inner core

    Takahashi S., Ohtani E., Sakai T., Mashino I., Kamada S., Miyahara M., Sakamaki T., Hirao N., Ohishi Y.

    AGU Fall meeting  2013.12 

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  • Melting relations and stability of Fe3C up to 230 GPa: Implication for the carbon in the Earth’s inner core

    Takahashi S., Ohtani E., Sakai T., Miyahara M., Kamada S., Mashino I., Hirao N., Ohishi Y.

    Japan Geoscience Union Meeting 2013  2013.3 

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  • Equation of state of Fe and Fe-Ni alloy at multi-megabar

    Sakai T., Takahashi S., Nishitani N, Mashino I., Ohtani E., Hirao N.

    AGU Fall meeting  2012.12 

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  • Equation of state of Fe3+-bearing Mg-perovskite in the lower mantle and effects of spin transition of iron

    Mashino I., Hirao N., Ohtani E., Sakai T., Hamada M., Nakano S., Akasaka M.

    AGU Fall meeting  2012.12 

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  • Fe0.9Ni0.1合金の状態方程式

    境毅, 高橋豪, 西谷尚也, 増野いづみ, 大谷栄治, 平尾直久

    第53回高圧討論会  2012.11 

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  • 核モノクロメータによる高圧放射光メスバウアー分光法の開発とX線回折との同時測定

    平尾直久, 大石泰生, 三井隆也, 増野いづみ, 浜田麻希, 松岡岳洋, 大谷栄治

    第53回高圧討論会  2012.11 

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  • Equations of state of vore materials; implication for the core composition

    Sakai T., Takahashi S., Nishitani N., Mashino I., Ohtani E., Hirao N.

    G-COE International Symposium “Achievements of G-COE Program for Earth and Planetary Dynamics and the Future Perspective  2012.9 

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  • Equation of state of Fe3+-bearing perovskite in Earth’s lower mantle and effects of spin transision of iron

    Mashino I., Hirao N., Ohtani E., Sakai T., Hamada M., Nakano S., Akasaka M.

    G-COE International Symposium “Achievements of G-COE Program for Earth and Planetary Dynamics and the Future Perspective  2012.9 

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  • 下部マントルにおけるFe3+を含むMg-ペロブスカイトの状態方程式とスピン転移の影響

    増野いづみ, 大谷栄治, 境毅, 浜田麻希, 中野智志, 赤坂正秀, 平尾直久

    日本鉱物科学会  2012.9 

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  • 放射光X線回折法およびスペクトロスコピーを併用した地球中心部の総合的解明

    増野いづみ, 大谷栄治, 境毅, 寺崎英紀, 村上元彦, 平尾直久, 大石泰生

    SPring-8シンポジウム2012  2012.8 

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Research Projects

  • Experimental study on deep mantle by Kawai-type multianvil press

    Grant number:21H04996  2021.07 - 2026.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (S)  Grant-in-Aid for Scientific Research (S)

    芳野 極, 辻野 典秀, 桑原 秀治, 増野 いづみ, 山崎 大輔

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    Grant amount:\193570000 ( Direct expense: \148900000 、 Indirect expense:\44670000 )

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  • ケイ酸塩ガラスの超高圧その場弾性波速度測定から導く最下部マントルのメルトの安定性

    Grant number:21K14013  2021.04 - 2023.03

    日本学術振興会  科学研究費助成事業 若手研究  若手研究

    増野 いづみ

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    Grant amount:\4550000 ( Direct expense: \3500000 、 Indirect expense:\1050000 )

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  • 超高温高圧その場物性精密測定から導き出す最下部マントルの地震波異常の原因

    Grant number:19K21049  2020.04 - 2022.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Research Activity start-up  Grant-in-Aid for Research Activity start-up

    増野 いづみ

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    Grant amount:\2860000 ( Direct expense: \2200000 、 Indirect expense:\660000 )

    ダイヤモンドアンビルセルを用いた高温高圧実験における高温発生方法は、主にレーザー加熱式と外熱式加熱に分けられる。外熱式の加熱方法を用いることで試料中の温度勾配が少なくすることができるが、技術的な困難さにより、現在まで下部マントル上部の温度圧力条件での測定にとどまっていた。本研究では真空チャンバーおよびグラファイトをヒーターに用いるなど、セル構成を工夫することにより、実際の地球マントル全領域を網羅するような条件まで発生温度圧力を拡張し、X線回折法や分光法と組み合わせ、マントル物質の物性を明らかにすることを目的としている。
    初年度である今年度は、真空チャンバーおよびグラファイトヒーターを導入した外熱式ダイヤモンドアンビル超高温高圧発生装置の開発に着手し、実際に放射光X線回折法やラマン分光法と組み合わせて高温高圧実験を行うことができた。放射光X線回折は兵庫県にあるSPring-8にて、ラマン分光測定は東京大学にて実験を行った。外熱式加熱には比較的低温下(1000K以下)の実験ではプラチナ・タングステン・モリブデン等の金属ワイヤーを使用した円柱状ヒーターを用い、高温下(1000K以上)の実験ではグラファイトヒーターと真空チャンバーを用い、H2O・Mg(OH)2・ブリッジマナイトの高温高圧その場X線回折データおよびラマンスペクトルの取得を試みた。H2Oにおいては、地球の下部マントル温度圧力条件である~1500K, 65万気圧までX線回折データの取得に成功した。

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  • 沈み込むスラブ物質の高温高圧下における弾性と融解関係の解明;地球内部の水のゆくえ

    Grant number:15J02017  2015.04 - 2017.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for JSPS Fellows  Grant-in-Aid for JSPS Fellows

    増野 いづみ

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    Grant amount:\2300000 ( Direct expense: \2300000 )

    今年度は前年度に引き続き、超高圧下における鉄を含むブリッジマナイトの音速測定を行い、今までに報告されている数倍以上の圧力であるメガバール圧力下までの鉄を含むブリッジマナイトの弾性波速度の測定に成功した。鉄を含むブリッジマナイトは下部マントルに最も多く存在する鉱物であるが、従来の研究では鉄を含むブリッジマナイトのメガバール圧力下における音速測定は実験の困難さにより行われていなかった。本実験の音速測定結果を用い、実際の地球の地震波観測データと比較することで、下部マントルの鉱物学的モデルをより強く制約することができる。本研究では音速測定に加え、ブリッジマナイトの音速に対する鉄の効果を決めるため、透過型電子顕微鏡(TEM)- 電子エネルギー損失分光法(EELS)装置を用いた高圧高温発生装置ダイヤモンドアンビルセル(DAC)の回収試料の鉄の量および価数の測定を試みた。鉄を含むブリッジマナイトのTEM-EELS測定はバイロイト大学バイエルン地球科学研究所で行った。その結果、鉄の濃度・鉄のスピン転移によりブリッジマナイトの音速が有意に変化することが明らかになった。現在、ブリッジマナイトの鉄の濃度およびスピン転移の効果を考慮に入れた下部マントルの鉱物学的モデルを検討しており、今までのところ下部マントルは上部マントルよりもSiに富むモデルがもっともらしいということが導き出された。上部マントルよりも下部マントルがSiに富むという結果は、地球の進化過程や地球の材料物質について大きな示唆を与える。Siが下部マントルに富むことで、現在のマントル対流は、従来考えられていたような一層対流とは異なる可能性が示唆される。また、地球の材料物質については、典型的なCIコンドライトとは一致せず、地球に特有のコンドライト(たとえばEarthコンドライトなど)を考える必要があることが示唆される。

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