OHFUJI Hiroaki

J-GLOBAL         Last updated: Dec 11, 2018 at 22:32
 
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Name
OHFUJI Hiroaki
Affiliation
Ehime University
Section
Geodynamics Research Center
Job title
Professor
Degree
Ph.D.(Cardiff University (UK))

Research Areas

 
 

Academic & Professional Experience

 
Apr 2016
 - 
Today
Professor, Geodynamics Research Center, Ehime University
 
Apr 2012
 - 
Mar 2016
Associate Professor, Geodynamics Reserch Center, Ehime University
 
Apr 2007
 - 
Mar 2012
Assistant Professor, Geodynamics Research Center, Ehime University
 
Oct 2005
 - 
Mar 2007
Assistant Professor, Geodynamics Research Center, Ehime University
 
Nov 2004
 - 
Sep 2005
Postdoctoral Fellow, Geodynamics Research Center, Ehime University
 

Education

 
Sep 2001
 - 
Oct 2004
Department of Earth, Ocean and Planetary Sciences, Cardiff University
 
Apr 1999
 - 
Mar 2001
Earth and Environmental Science, Graduate School of Science and Technology, Niigata University
 
Apr 1995
 - 
Mar 1999
Department of Geology, Faculty of Science, Niigata University
 

Awards & Honors

 
Sep 2017
Award of Japan Association of Mineralogical Sciences, Japan Association of Mineralogical Sciences
 
Sep 2002
Overseas Research Student Award, Universities UK
 

Published Papers

 
Rei Fukuta, Naoya Yamamoto, Fumitaro Ishikawa, Fumitaro Ishikawa, Masafumi Matsushita, Masafumi Matsushita, Tsuyoshi Yoshitake, Hiroshi Ikenoue, Hiroaki Ohfuji, Toru Shinmei, Tetsuo Irifune
Japanese Journal of Applied Physics   57    Nov 2018
© 2018 The Japan Society of Applied Physics. We propose a simple and easy electrode formation technique on nanopolycrystalline diamond (NPD) synthesized by a high-temperature and high-pressure technique. The stronger light absorption nature of NPD...
Yasuhide Nakamura, Izumi Iwata, Izumi Iwata, Rie S. Hori, Naomi Uchiyama, Akihiro Tuji, Masaki J. Fujita, Daiske Honda, Daiske Honda, Hiroaki Ohfuji
Journal of Structural Biology   204 45-51   Oct 2018
© 2018 Elsevier Inc. Cross-sections were prepared by ultramicrotome (UM) and focused ion beam (FIB) system in order to examine the skeletal structure of ecologically and geologically important shell-bearing protists: phaeodarians and radiolarians....
Y. Zhou, T. Irifune, T. Irifune, H. Ohfuji, T. Kuribayashi
Geophysical Research Letters   45 8167-8172   Aug 2018
©2018. American Geophysical Union. All Rights Reserved. Phase relations of Al2SiO5 have been studied by multianvil experiments at pressures of 13–23 GPa and temperatures of 2000–2900 K. Al2SiO5 kyanite was found to transform into two new high-pres...
Li Lei, Leilei Zhang, Shangpan Gao, Qiwei Hu, Leiming Fang, Xiping Chen, Yuanhua Xia, Xianlong Wang, Hiroaki Ohfuji, Yohei Kojima, Simon A.T. Redfern, Zhi Zeng, Bo Chen, Duanwei He, Tetsuo Irifune
Journal of Alloys and Compounds   752 99-105   Jul 2018
© 2018 Elsevier B.V. Binary ε-Fe3N1.098 and ternary ε-Fe2.322Co0.678N0.888 were synthesized as spherical bulk materials using novel high-pressure solid-state metathesis reactions (HPSSM). The structural and magnetic properties of the two nitrides ...
N. Chertkova, H. Ohfuji, R. Nomura, H. Kadobayashi, T. Irifune
High Pressure Research   38 337-347   Jul 2018
© 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group. Using an external heating system, specifically designed for the lever-type diamond anvil cell, we investigated for the first time the phase relationships in the C2H2O4 system ...
Yoshio Ichida, Hiroaki Ohfuji, Tetsuo Irifune, Takehiro kunimoto, Yohei Kojima, Toru Shinmei
Journal of the European Ceramic Society   38 2815-2822   Jul 2018
© 2018 Elsevier Ltd Using a turbostratic pyrolytic boron nitride as a starting material, we synthesized a variety of ultrahard polycrystalline cubic boron nitride (PcBN) as a function of the heating duration changing from 1 to 60 min under a const...
D. S. Mikhailenko, O. V. Shchepetova, K. A. Musiyachenko, A. V. Korsakov, Hiroaki Ohfuji, I. V. Pekov
Doklady Earth Sciences   480 814-817   Jun 2018
© 2018, Pleiades Publishing, Ltd. The results of studying an aggregate of graphite-and-diamond crystal in tourmaline 5 μm of the Kokchetav massif by the method of transmission electron microscopy are presented. The detail studies of the interface ...
Takashi Mizuguchi, Tsutomu Ito, Tsutomu Ito, Kota Kimura, Kota Kimura, Tokiko Kurisaka, Hiroaki Ohfuji
Zairyo/Journal of the Society of Materials Science, Japan   67 568-573   May 2018
© 2018 The Society of Materials Science, Japan. The stress–strain relationship and microstructural evolution of a fine-grained 5083 aluminum alloy produced via friction-stir processing (FSP) during high-temperature tensile deformation were investi...
Terumi Ejima, Yasuhito Osanai, Masahide Akasaka, Tatsuro Adachi, Nobuhiko Nakano, Yoshiaki Kon, Hiroaki Ohfuji, Jargalan Sereenen
Minerals   8    May 2018
© 2018 by the authors. Licensee MDPI, Basel, Switzerland. The oxidation states of Fe within olivine, orthopyroxene, clinopyroxene, and spinel in a spinel lherzolite xenolith from the Tariat Depression, Mongolia were investigated using57Fe Mössbaue...
Hirokazu Kadobayashi, Hisako Hirai, Hiroaki Ohfuji, Michika Ohtake, Yoshitaka Yamamoto
Journal of Chemical Physics   148    Apr 2018
© 2018 Author(s). High-temperature and high-pressure experiments were performed under 2-55 GPa and 298-653 K using in situ Raman spectroscopy and X-ray diffraction combined with externally heated diamond anvil cells to investigate the stability of...
Keisuke Niwase, Mititaka Terasawa, Shin Ichi Honda, Masahito Niibe, Tomohiko Hisakuni, Tadao Iwata, Yuji Higo, Takeshi Hirai, Toru Shinmei, Hiroaki Ohfuji, Tetsuo Irifune
Journal of Applied Physics   123    Apr 2018
© 2018 Author(s). The super hard material of "compressed graphite" (CG) has been reported to be formed under compression of graphite at room temperature. However, it returns to graphite under decompression. Neutron-irradiated graphite, on the othe...
Takeshi Sakai, Takehiko Yagi, Tetsuo Irifune, Tetsuo Irifune, Hirokazu Kadobayashi, Naohisa Hirao, Takehiro Kunimoto, Hiroaki Ohfuji, Saori Kawaguchi-Imada, Yasuo Ohishi, Shigehiko Tateno, Kei Hirose, Kei Hirose
High Pressure Research   38 107-119   Apr 2018
© 2018 Informa UK Limited, trading as Taylor & Francis Group. We have developed a double stage diamond anvil cell (ds-DAC) technique for reproducible pressure by precisely fabricating 2nd stage anvils using a focused ion beam system. We used 2nd...
Rei Fukuta, Fumitaro Ishikawa, Akihiro Ishikawa, Kohsuke Hamada, Masafumi Matsushita, Hiroaki Ohfuji, Toru Shinmei, Tetsuo Irifune
Diamond and Related Materials   84 66-70   Apr 2018
© 2018 Elsevier B.V. We investigated inherent electronic properties of ultra-hard nano-polycrystalline diamond (NPD) synthesised at 15 GPa and 2300 °C. NPD exhibited a p-type semiconducting property with a resistivity of 1 × 106and 4 × 102Ω cm at ...
Leilei Zhang, Ya Cheng, Ya Cheng, Li Lei, Xianlong Wang, Xianlong Wang, Qiwei Hu, Qiming Wang, Hiroaki Ohfuji, Yohei Kojima, Qiang Zhang, Zhi Zeng, Zhi Zeng, Fang Peng, Zili Kou, Duanwei He, Tetsuo Irifune
Crystal Growth and Design   18 1843-1847   Mar 2018
© 2018 American Chemical Society. The well-crystallized mixed anions compound cerium oxychloride (CeOCl) was successfully synthesized by a high-pressure solid-state metathesis reaction. The photoluminescence experiment shows that the CeOCl, with a...
Lei Qi, Li Lei, Qiwei Hu, Leilei Zhang, Leihao Feng, Meifang Pu, Hiroaki Ohfuji, Tetsuo Irifune
Journal of Applied Physics   123    Feb 2018
© 2018 Author(s). Introducing interstitial nitrogen atoms into the rhenium lattices is accepted for enhancing the mechanical and thermal properties of the metal. Here, we present an experimental study on the strengthening effects of interstitial n...
Mititaka Terasawa, Shin ichi Honda, Keisuke Niwase, Masahito Niibe, Tomohiko Hisakuni, Tadao Iwata, Yuji Higo, Toru Shinmei, Hiroaki Ohfuji, Tetsuo Irifune
Diamond and Related Materials   82 132-136   Feb 2018
© 2018 Elsevier B.V. Highly oriented pyrolytic graphite (HOPG) is a unique source material for the synthesis of new types of diamond. It can transform to layered nano-polycrystalline diamond (NPD) under static high pressure and high temperature (H...
Lei Hao Feng, Qi Wei Hu, Li Lei, Lei Ming Fang, Lei Qi, Lei Lei Zhang, Mei Fang Pu, Zi Li Kou, Fang Peng, Xi Ping Chen, Yuan Hua Xia, Yohei Kojima, Hiroaki Ohfuji, Duan Wei He, Bo Chen, Tetsuo Irifune
Chinese Physics B   27    Feb 2018
© 2018 Chinese Physical Society and IOP Publishing Ltd. Tantalum nitride (TaN) compact with a Vickers hardness of 26 GPa is prepared by a high-pressure and hightemperature (HPHT) method. The crystal structure and atom occupations of WC-type TaN ha...
Qiwei Hu, Xiaozhi Yan, Li Lei, Qiming Wang, Leihao Feng, Lei Qi, Leilei Zhang, Fang Peng, Hiroaki Ohfuji, Duanwei He
Physical Review B   97    Jan 2018
© 2018 American Physical Society. Pressure induced solid-solid reconstructive phase transitions for graphite-diamond, and wurtzite-rocksalt in GaN and AlN occur at significantly higher pressure than expected from equilibrium coexistence and their ...
Hiroaki Ohfuji
Japanese Magazine of Mineralogical and Petrological Sciences   47 1-12   Jan 2018
© 2018. Here I introduce the crystallization and texturing mechanism of nano-polycrystalline diamond (NPD) in the graphite-diamond direct transformation in laboratory and in nature. Two types of transformation processes, diŠusion-controlled (nucle...
Naira S. Martirosyan, Naira S. Martirosyan, Konstantin D. Litasov, Konstantin D. Litasov, Sergey S. Lobanov, Alexander F. Goncharov, Anton Shatskiy, Anton Shatskiy, Hiroaki Ohfuji, Vitali Prakapenka
Geoscience Frontiers      Jan 2018
© 2018 China University of Geosciences (Beijing) and Peking University The fate of subducted carbonates in the lower mantle and at the core-mantle boundary was modelled via experiments in the MgCO3-Fe0 system at 70–150 GPa and 800–2600 K in a lase...
H. Kadobayashi, H. Hirai, H. Ohfuji, Y. Kojima, Y. Ohishi, N. Hirao, M. Ohtake, Y. Yamamoto
Journal of Physics: Conference Series   950    Nov 2017
© Published under licence by IOP Publishing Ltd. The phase transition mechanism of methane hydrate from sH to filled-ice Ih structure was examined using a combination of time-resolved X-ray diffractometry (XRD) and Raman spectroscopy in conjunctio...
Olga V. Shchepetova, Olga V. Shchepetova, Andrey Korsakov, Andrey Korsakov, Denis Mikhailenko, Denis Mikhailenko, Pavel Zelenovskiy, Vladimir Shur, Hiroaki Ohfuji
Journal of Raman Spectroscopy   48 1606-1612   Nov 2017
Copyright © 2017 John Wiley & Sons, Ltd. Confocal 2D and 3D Raman imaging was applied to SiO 2 inclusions in kyanite porphyroblasts from diamond-bearing kyanite gneisses of the Kokchetav Massif (Northern Kazakhstan). The study reveals a mineral ...
Tomohiro Ohuchi, Xinglin Lei, Hiroaki Ohfuji, Yuji Higo, Yoshinori Tange, Takeshi Sakai, Kiyoshi Fujino, Tetsuo Irifune, Tetsuo Irifune
Nature Geoscience   10 771-775   Oct 2017
© 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved. The occurrence of intermediate-depth and deep earthquakes at depths greater than 60 km in subducting slabs has long puzzled geoscientists. These earthquakes require...
Yoshio Ichida, Hiroaki Ohfuji, Tetsuo Irifune, Takehiro Kunimoto, Yohei Kojima, Toru Shinmei
Diamond and Related Materials   77 25-34   Aug 2017
© 2017 Elsevier B.V. Using a turbostratic pyrolytic boron nitride produced by a chemical vapor deposition process as a starting material, we conducted experiments for synthesizing polycrystalline cubic boron nitride (PcBN) at a temperature of 1600...
T. Kimura, H. Ohfuji, M. Nishi, T. Irifune
Nature Communications   8    Jun 2017
© The Author(s) 2017. Periclase (MgO) is the second most abundant mineral after bridgmanite in the Earth's lower mantle, and its melting behaviour under pressure is important to constrain rheological properties and melting behaviours of the lower ...
Norimasa Nishiyama, Ryo Ishikawa, Hiroaki Ohfuji, Hauke Marquardt, Alexander Kurnosov, Takashi Taniguchi, Byung Nam Kim, Hidehiro Yoshida, Atsunobu Masuno, Jozef Bednarcik, Eleonora Kulik, Eleonora Kulik, Yuichi Ikuhara, Fumihiro Wakai, Tetsuo Irifune, Tetsuo Irifune
Scientific Reports   7    Mar 2017
© The Author(s) 2017.Glasses and single crystals have traditionally been used as optical windows. Recently, there has been a high demand for harder and tougher optical windows that are able to endure severe conditions. Transparent polycrystalline ...
Terumi Ejima, Terumi Ejima, Terumi Ejima, Mari Yoneda, Masahide Akasaka, Hiroaki Ohfuji, Yoshiaki Kon, Mariko Nagashima, Yoshihiro Nakamuta
Journal of Mineralogical and Petrological Sciences   112 116-126   Jan 2017
Mineral precipitates within olivine grains are a sensitive recorder of the oxidation conditions of scoria. The crystallization process of precipitates within olivine phenocrysts in andesitic scoria from Kasayama volcano, Hagi, Yamaguchi Prefecture...
Nico A. Gaida, Nico A. Gaida, Norimasa Nishiyama, Norimasa Nishiyama, Atsunobu Masuno, Atsunobu Masuno, Ulrich Schürmann, Christopher Giehl, Oliver Beermann, Hiroaki Ohfuji, Jozef Bednarcik, Eleonora Kulik, Eleonora Kulik, Astrid Holzheid, Tetsuo Irifune, Tetsuo Irifune, Lorenz Kienle
Journal of the American Ceramic Society      Jan 2017
© 2017 American Ceramic Society. Transparent polycrystalline nanoceramics consisting of triclinic Al 2 SiO 5 kyanite (91.4 vol%) and Al 2 O 3 corundum (8.6 vol%) were fabricated at 10 GPa and 1200-1400°C. These materials were obtained by direct co...
Takashi Mizuguchi, Tsutomu Ito, Tsutomu Ito, Kota Kimura, Tokiko Kurisaka, Hiroaki Ohfuji, Masaki Kimura
Keikinzoku/Journal of Japan Institute of Light Metals   67 361-366   Jan 2017
© 2017 The Japan Institute of Light Metals. This work investigated the microstructural evolution occurring during high-temperature tensile tests (743 K, strain rate 1×10 -3 s -1 ) of a friction stir processed polycrystalline solid solution 5083 a...
Zhaodong Liu, Zhaodong Liu, Masayuki Nishi, Takayuki Ishii, Hongzhan Fei, Nobuyoshi Miyajima, Tiziana Boffa Ballaran, Hiroaki Ohfuji, Takeshi Sakai, Lin Wang, Svyatoslav Shcheka, Takeshi Arimoto, Yoshinori Tange, Yuji Higo, Tetsuo Irifune, Tomoo Katsura
Journal of Geophysical Research: Solid Earth      Jan 2017
©2017. American Geophysical Union. All Rights Reserved. Phase relations in the system MgSiO 3 -Al 2 O 3 were investigated at pressures of 27-45 GPa and temperatures of 1700, 2000, and 2300 K using sintered diamond and tungsten carbide anvils in a ...
Youmo Zhou, Tetsuo Irifune, Tetsuo Irifune, Hiroaki Ohfuji, Toru Shinmei, Wei Du, Wei Du
Physics and Chemistry of Minerals   44 33-42   Jan 2017
© 2016, Springer-Verlag Berlin Heidelberg.Lingunite (hollandite with Na contents of 80–85 mol%) discovered in the shock veins of strongly shocked meteorites is an important signature of shock metamorphism. To seek the stability region of lingunite...
Hiroaki Ohfuji, Motosuke Nakaya, Alexander P. Yelisseyev, Valentin P. Afanasiev, Konstantin D. Litasov, Konstantin D. Litasov
Journal of Mineralogical and Petrological Sciences   112 46-51   Jan 2017
This study revealed for the first time the microtexture and crystallographic features of natural polycrystalline diamond, yakutite found in placer deposits in the Siberian Platform, Russia. Yakutite consists of well-sintered nanocrystalline (5-50 ...
Nico A. Gaida, Nico A. Gaida, Norimasa Nishiyama, Norimasa Nishiyama, Atsunobu Masuno, Atsunobu Masuno, Astrid Holzheid, Hiroaki Ohfuji, Ulrich Schürmann, Christin Szillus, Eleonora Kulik, Eleonora Kulik, Jozef Bednarcik, Oliver Beermann, Christopher Giehl, Lorenz Kienle
Journal of the American Ceramic Society   100 323-332   Jan 2017
© 2016 The American Ceramic SocietyWe report the synthesis of alumina/stishovite nano-nano composite ceramics through a pressure-induced dissociation in Al2SiO5 at a pressure of 15.6 GPa and temperatures of 1300°C-1900°C. Stishovite is a high-pres...
T. Irifune, T. Irifune, K. Kawakami, T. Arimoto, H. Ohfuji, T. Kunimoto, T. Shinmei
Nature Communications   7    Dec 2016
Transparent ceramics are important for scientific and industrial applications because of the superior optical and mechanical properties. It has been suggested that optical transparency and mechanical strength are substantially enhanced if transpar...
Hiroyuki Kagi, Dmitry A. Zedgenizov, Dmitry A. Zedgenizov, Hiroaki Ohfuji, Hidemi Ishibashi
Geochemistry International   54 834-838   Oct 2016
© 2016, Pleiades Publishing, Ltd.We report cloudy micro- and nano-inclusions in a superdeep diamond from São-Luiz, Brazil which contains inclusions of ferropericlase (Mg, Fe)O and former bridgmanite (Mg, Fe)SiO3 and ringwoodite (Mg, Fe)2SiO4. Fiel...
Hidemi Ishibashi, Hiroyuki Kagi, Shoko Odake, Hiroyuki Ohfuji, Hiroshi Kitawaki
Geochemistry International   54 882-889   Oct 2016
© 2016, Pleiades Publishing, Ltd.Field Emission SEM (FESEM) textural observations, crystal size distribution (CSD) analyses, UV-excited luminescence imaging, and photoluminescence (PL) microspectroscopy excited by 488 nm laser were conducted on tw...
Shang Pan Gao, Li Lei, Qi Wei Hu, Lei Ming Fang, Xian Long Wang, Hiroaki Ohfuji, Yohei Kojima, Lei Lei Zhang, Li Jie Tan, Zhi Zeng, Fang Peng, Duan Wei He, Tetsuo Irifune
Gaoya Wuli Xuebao/Chinese Journal of High Pressure Physics   30 265-270   Aug 2016
© 2016, Editorial Board of Chinese Journal of High Pressure Physics. All right reserved.Ternary ε-Fe3-xMxN1+δ (M=Co,Ni) were synthesized as spherical bulk materials with variable components through composite high-pressure solid-state metathesis (H...
Péter Németh, Kurt Leinenweber, Hiroaki Ohfuji, Thomas Groy, Kenneth J. Domanik, István J. Kovács, Judit S. Kovács, Peter R. Buseck, Peter R. Buseck
Earth and Planetary Science Letters      Jul 2016
© 2017 Elsevier B.V.Water-bearing minerals provide fundamental knowledge regarding the water budget of the mantle and are geophysically significant through their influence on the rheological and seismic properties of Earth's interior. Here we inve...
Taku Fujii, Hiroaki Ohfuji, Toru Inoue
Physics and Chemistry of Minerals   1-9   Feb 2016
© 2016 Springer-Verlag Berlin Heidelberg Calcium sulfate (CaSO4), one of the major sulfate minerals in the Earth’s crust, is expected to play a major role in sulfur recycling into the deep mantle. Here, we investigated the crystal structure and ph...
Ayako Shinozaki, Ayako Shinozaki, Hiroyuki Kagi, Hisako Hirai, Hiroaki Ohfuji, Taku Okada, Satoshi Nakano, Takehiko Yagi
Physics and Chemistry of Minerals   1-9   Dec 2015
© 2015 Springer-Verlag Berlin Heidelberg Stability andphase relations of coexisting enstatite and H2 fluid were investigated in the pressure and temperature regions of 3.1–13.9 GPa and 1500–2000 K using laser-heated diamond-anvil cells. XRD measur...
T. Ejima, T. Ejima, M. Akasaka, T. Nagao, H. Ohfuji
Mineralogical Magazine   79 1833-1848   Dec 2015
© 2016 by Walter de Gruyter Berlin/Boston.The oxidation state of Fe and precipitates within olivine phenocrysts froman olivine-basalt from Kuroshima volcano, Goto Islands, Nagasaki Prefecture, Japan, were determined using electron microprobe analy...
Eleonora Kulik, Eleonora Kulik, Norimasa Nishiyama, Norimasa Nishiyama, Atsunobu Masuno, Yan Zubavichus, Vadim Murzin, Evgeny Khramov, Akihiro Yamada, Hiroaki Ohfuji, Hans Christian Wille, Tetsuo Irifune, Tetsuo Irifune, Tomoo Katsura
Journal of the American Ceramic Society   98 4111-4116   Dec 2015
© 2015 The American Ceramic Society. High pressure and temperature synthesis of compositions made of (Si1-x,Gex)O2 where x is equal to 0, 0.1, 0.2, 0.5, 0.7, and 1 was performed at 7-12 GPa and 1200-1600°C using a Kawai-type high-pressure apparatu...
Hiroaki Ohfuji, Tetsuo Irifune, Tetsuo Irifune, Konstantin D. Litasov, Konstantin D. Litasov, Tomoharu Yamashita, Futoshi Isobe, Valentin P. Afanasiev, Nikolai P. Pokhilenko
Scientific Reports   5    Oct 2015
Consolidated bodies of polycrystalline diamond with grain sizes less than 100 nm, nanopolycrystalline diamond (NPD), has been experimentally produced by direct conversion of graphite at high pressure and high temperature. NPD has superior hardness...
Hideaki Yasuhara, Naoki Kinoshita, Hiroaki Ohfuji, Manabu Takahashi, Kazumasa Ito, Kiyoshi Kishida
Water Resources Research   51 5425-5449   Jul 2015
© 2015. American Geophysical Union. All Rights Reserved. In this study, a series of long-term, intermittent permeability experiments utilizing Berea sandstone and Horonobe mudstone samples, with and without a single artificial fracture, is conduct...
Takeshi Sakai, Takehiko Yagi, Hiroaki Ohfuji, Tetsuo Irifune, Tetsuo Irifune, Yasuo Ohishi, Naohisa Hirao, Yuya Suzuki, Yasushi Kuroda, Takayuki Asakawa, Takashi Kanemura
Review of Scientific Instruments   86    Mar 2015
© 2015 AIP Publishing LLC. Micron-sized diamond anvils with a 3 μm culet were successfully processed using a focused ion beam (FIB) system and the generation of high pressures was confirmed using the double stage diamond anvil cell technique. The ...
Taku Fujii, Hiroaki Ohfuji
Measurement Science and Technology   26    Feb 2015
© 2015 IOP Publishing Ltd. Pressure estimation using the frequency shift of the diamond Raman peak from the anvil culet is readily and widely used in diamond anvil cell experiments along with the conventional ruby fluorescence method. Here, we pro...
Mitsuhiro Okayasu, Shuhei Takeuchi, Masaki Yamamoto, Hiroaki Ohfuji, Toshihiro Ochi
Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science   46 1597-1609   Jan 2015
© 2015, The Minerals, Metals & Materials Society and ASM International. The effects of microstructural characteristics (secondary dendrite arm spacing, SDAS) and Si- and Fe-based eutectic structures on the mechanical properties and failure behavio...
Koji Maruyama, Hiroyuki Kagi, Toru Inoue, Hiroaki Ohfuji, Toru Yoshino
Chemistry Letters   44 434-436   Jan 2015
© 2015 The Chemical Society of Japan. Pressure-induced crystallization from amorphous calcium carbonate (ACC) was observed with X-ray diffraction at room temperature. Time-resolved diffraction patterns revealed that calcite and vaterite simultaneo...
Hiroaki Ohfuji, Masashi Yamamoto
Journal of Mineralogical and Petrological Sciences   110 189-195   Jan 2015
This study demonstrates the validity of a thin osmium coating for quantitative energy-dispersive spectroscopic (EDS) analysis, particularly for light elements such as O (and potentially C and N) in natural/synthetic minerals. An osmium coating pre...
Nao Cai, Toru Inoue, Kiyoshi Fujino, Hiroaki Ohfuji, Hisayoshi Yurimoto
American Mineralogist   100 2330-2335   Jan 2015
© 2015 by Walter de Gruyter Berlin/Boston. A new Al-bearing hydrous Mg-silicate that we named as 23 Å phase was synthesized at 10 GPa and 1000 °C, while also coexisting with diaspore and pyrope in the following system: phase A [Mg7Si2O8(OH)6] + Al...
Yoshio Kono, Curtis Kenney-Benson, Daniel Hummer, Hiroaki Ohfuji, Changyong Park, Guoyin Shen, Yanbin Wang, Abby Kavner, Craig E. Manning
Nature Communications   5    Oct 2014
© 2014 Macmillan Publishers Limited. All rights reserved. Knowledge of the occurrence and mobility of carbonate-rich melts in the Earth's mantle is important for understanding the deep carbon cycle and related geochemical and geophysical processes...
M. Okayasu, H. Fukui, H. Ohfuji, T. Shiraishi
Materials Science and Technology (United Kingdom)   30 301-308   Mar 2014
The strain induced martensitic transformation (SMT) of the austenite stainless steel (SUS 304) under cyclic loading and static loading was investigated directly using electron backscattered diffraction. Two different SMT characteristics are observ...
M. Okayasu, K. Ota, S. Takeuchi, H. Ohfuji, T. Shiraishi
Materials Science and Engineering A   592 189-200   Jan 2014
The effects of microstructural characteristics on the mechanical properties of an aluminum alloy (ADC12: Al-Si11.3-Cu1.9-Zn0.8-Fe0.8-Mg0.2-Mn0.2) produced by various casting technologies are studied experimentally and numerically. Six different ca...
Kiyoshi Fujino, Daisuke Nishio-Hamane, Takaya Nagai, Yusuke Seto, Yasuhiro Kuwayama, Matthew Whitaker, Matthew Whitaker, Hiroaki Ohfuji, Toru Shinmei, Tetsuo Irifune, Tetsuo Irifune
Physics of the Earth and Planetary Interiors   228 186-191   Jan 2014
Spin transition and substitution of Fe3+ in Fe3+AlO3-bearing MgSiO3 perovskite (Pv) and post-perovskite (PPv) were examined up to 200 and 165GPa, respectively, at room temperature by X-ray emission spectroscopy (XES) and XRD. The results of XES an...
Mitsuhiro Okayasu, Shuhei Takeuchi, Hiroaki Ohfuji
Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science   45 5767-5776   Jan 2014
© 2014, The Minerals, Metals & Materials Society and ASM International. The mechanical properties and failure characteristics of a cast Mg alloy (AZ91: Mg-Al<inf>8.9</inf>-Zn<inf>0.6</inf>-Mn<inf>0.2</inf>) produced by a heated-mold continuous cas...
Norimasa Nishiyama, Norimasa Nishiyama, Fumihiro Wakai, Hiroaki Ohfuji, Yusuke Tamenori, Hidenobu Murata, Takashi Taniguchi, Masafumi Matsushita, Manabu Takahashi, Eleonora Kulik, Eleonora Kulik, Kimiko Yoshida, Kouhei Wada, Jozef Bednarcik, Tetsuo Irifune, Tetsuo Irifune
Scientific Reports   4    Jan 2014
Silicon dioxide has eight stable crystalline phases at conditions of the Earth's rocky parts. Many metastable phases including amorphous phases have been known, which indicates the presence of large kinetic barriers. As a consequence, some crystal...
Ayako Shinozaki, Hiroyuki Kagi, Naoki Noguchi, Naoki Noguchi, Hisako Hirai, Hiroaki Ohfuji, Taku Okada, Satoshi Nakano, Takehiko Yagi
American Mineralogist   99 1265-1269   Jan 2014
Species dissolved in H2 fluid were investigated in a SiO2-H2 system. Raman and infrared (IR) spectra were measured at high pressure and room temperature after heating experiments were conducted at two pressure and temperature conditions: 2.0 GPa, ...
Norimasa Nishiyama, Takashi Taniguchi, Hiroaki Ohfuji, Kimiko Yoshida, Fumihiro Wakai, Byung Nam Kim, Hidehiro Yoshida, Yuji Higo, Astrid Holzheid, Oliver Beermann, Tetsuo Irifune, Yoshio Sakka, Ken Ichi Funakoshi
Scripta Materialia   69 362-365   Sep 2013
Transparent nanocrystalline bulk alumina was obtained at 7.7 GPa and 800 C. The alumina has an average grain size of ∼150 nm and an in-line transmission of 71% for a wavelength of 640 nm and a thickness of 0.8 mm. The values of microhardness and f...
Mitsuhiro Okayasu, Hironobu Fukui, Hiroaki Ohfuji, Tetsuro Shiraishi
Journal of Materials Science   48 6157-6166   Sep 2013
In situ measurements of the strain-induced martensitic transformation (SMTs) of SUS304 stainless steel that takes place during tensile loading at room temperature were performed around the notch of a dumbbell-shaped specimen where high stress conc...
Yohei Kojima, Hiroaki Ohfuji
Diamond and Related Materials   39 1-7   Aug 2013
The crystal structure of carbon nitride under high pressure and temperature was investigated up to megabar pressures using graphitic C3N 4 as a starting material. It transformed to an orthorhombic phase above 30 GPa and 1600 K, which has a similar...
Ayako Shinozaki, Ayako Shinozaki, Hisako Hirai, Hiroaki Ohfuji, Taku Okada, Shin Ichi Machida, Shin Ichi Machida, Takehiko Yagi
American Mineralogist   98 1604-1609   Aug 2013
High-pressure and high-temperature experiments were carried out in a Mg2SiO4-H2 system using laser-heated diamond-anvil cells to understand the influence of H2 fluid on the stability of forsterite. In situ X ray diffraction experiments and Raman s...
Lei Ming Fang, Lei Ming Fang, Xi Ping Chen, H. Ohfuji, T. Irifune, Guang Ai Sun, Bo Chen, Shu Ming Peng
Chinese Physics C   37    Aug 2013
High pressure pyrolysis of melamine has been attracting great interest recently, due to it being considered as a suitable precursor to realize the g-C3N4 and even superhard C3N4. In this work, we studied the detailed pyrolysis behavior of melamine...
Leiming Fang, Leiming Fang, Hiroaki Ohfuji, Tetsuo Irifune
Journal of Nanomaterials   2013    Jul 2013
We developed a novel technique to synthesize nanodiamond powder through the decomposition of graphitic C3N4 under high pressure and high temperature. The nanodiamond obtained by the present method is in an extremely pure form with no sp2 carbon co...
Li Lei, Li Lei, Hiroaki Ohfuji, Jiaqian Qin, Jiaqian Qin, Xinyu Zhang, Fulong Wang, Tetsuo Irifune
Solid State Communications   164 6-10   Jun 2013
The high-pressure phase transitions and Raman phonon behaviors of LiGaO2 were investigated by high-pressure Raman spectroscopy and first-principle calculations. The β-LiGaO2 was evidenced to undergo irreversible phase transitions to Raman silent γ...
Futoshi Isobe, Hiroaki Ohfuji, Hitoshi Sumiya, Tetsuo Irifune
Journal of Nanomaterials   2013    May 2013
A new type of polycrystalline sintered diamond has been successfully synthesized by direct conversion from highly oriented pyrolytic graphite at 15 GPa and 2300°C. It is optically transparent and consists entirely of layered nanocrystals (50-100 n...
Terumi Ejima, Masahide Akasaka, Takashi Nagao, Hiroaki Ohfuji
Journal of Mineralogical and Petrological Sciences   108 25-36   Apr 2013
Oxidation states of Fe and precipitates within olivine in orthopyroxene-olivine-clinopyroxene andesite (Opx-Ol-Cpx andesite) lava from Kasayama volcano, Hagi, Yamaguchi Prefecture, were investigated to reveal the oxidation process of the lava at h...
Kiyoshi Fujino, Daisuke Nishio-Hamane, Yasuhiro Kuwayama, Nagayoshi Sata, Sayaka Murakami, Matthew Whitaker, Matthew Whitaker, Ayako Shinozaki, Hiroaki Ohfuji, Yohei Kojima, Tetsuo Irifune, Nozomu Hiraoka, Hirofumi Ishii, Ku Ding Tsuei
Physics of the Earth and Planetary Interiors   217 31-35   Apr 2013
The spin transition and substitution of Fe3+ in Mg0.85Fe3+ 0.15Al0.15Si0.85O3 post-Mg-perovskite (PPv) synthesized at 165-170GPa, 2100K were examined by X-ray emission spectroscopy (XES) and X-ray diffraction (XRD) during decompression to 37GPa wi...
Mitsuhiro Okayasu, Yuki Ohkura, Tatsuaki Sakamoto, Shuhei Takeuchi, Hiroaki Ohfuji, Tetsuro Shiraishi
Materials Science and Engineering A   560 643-652   Jan 2013
To better understand the fatigue and tensile properties of SPCC steels welded by metal inert gas welding, the mechanical properties of the welded component in several localized regions, e.g., weld metal, heat affected zone (HAZ) and base metal, we...
Masayuki Nishi, Tomoaki Kubo, Hiroaki Ohfuji, Takumi Kato, Yu Nishihara, Tetsuo Irifune
Earth and Planetary Science Letters   361 44-49   Jan 2013
Si4++M2+↔2Al3+ (M=Mg+Fe+Ca) interdiffusion rates in majoritic garnet have been determined at pressure of 17GPa and temperatures of 1550-1700°C using a Kawai-type high-pressure apparatus. The diffusion profiles were measured across the interface be...
Yoshio Kono, Yoshio Kono, Tetsuo Irifune, Hiroaki Ohfuji, Yuji Higo, Ken Ichi Funakoshi
Geophysical Research Letters   39    Dec 2012
Compressional (Vp) and shear (Vs) wave velocities of mid-ocean-ridge basalt (MORB) was investigated at in situ high pressure and high temperature conditions of the mantle transition region by using a combination of ultrasonic and in situ x-ray mea...
Masayuki Nishi, Tetsuo Irifune, Hiroaki Ohfuji, Yoshinori Tange
Geophysical Research Letters   39    Dec 2012
The mechanism of the post-garnet transformation in natural single-crystalline pyropic garnet has been examined under large overpressure conditions of ∼31-43GPa using the multianvil apparatus with sintered diamond anvils. Intracrystalline nucleatio...
Norimasa Nishiyama, Norimasa Nishiyama, Satoshi Seike, Teruo Hamaguchi, Tetsuo Irifune, Masafumi Matsushita, Manabu Takahashi, Hiroaki Ohfuji, Yoshio Kono
Scripta Materialia   67 955-958   Dec 2012
Nanocrystalline bulk stishovite, with pure SiO 2 composition, was synthesized under high pressure and temperature. We found that this material has an extremely high fracture toughness (∼13 MPa m 1/2), nearly eight times higher than that of stishov...
Terumi Ejima, Masahide Akasaka, Takashi Nagao, Hiroaki Ohfuji
Journal of Mineralogical and Petrological Sciences   107 215-225   Dec 2012
The oxidation state of an olivine phenocryst separate from clinopyroxene-olivine andesitic black scoria with red-brown tint from Kasayama volcano, Hagi, Yamaguchi Prefecture, was determined using 57Fe Mössbauer spectroscopy, to examine the effect ...
A. Kurio, A. Kurio, Y. Tanaka, H. Sumiya, T. Irifune, T. Shinmei, H. Ohfuji, H. Kagi
Journal of Superhard Materials   34 343-349   Nov 2012
Wear resistance of nano-polycrystalline diamond (NPD) rods containing various amounts of hexagonal diamond has been tested with a new method for practical evaluation of the wear-resistance rate of superhard ceramics, in addition to the measurement...
Xi Liu, Xi Liu, Hiroaki Ohfuji, Norimasa Nishiyama, Qiang He, Takeshi Sanehira, Tetsuo Irifune
Journal of Geophysical Research: Solid Earth   117    Sep 2012
Multianvil experiments with long experimental durations have been made with the anorthite composition CaAl<inf>2</inf>Si<inf>2</inf>O<inf>8</inf> at pressure-temperature (P-T) conditions of 14-25 GPa and 1400-2400° C. At subsolidus conditions, the...
Li Lei, Li Lei, Hiroaki Ohfuji, Tetsuo Irifune, Jiaqian Qin, Xinyu Zhang, Toru Shinmei
Journal of Applied Physics   112    Aug 2012
Disorder-activated phonon behaviors of the cubic rocksalt-type semiconductor alloy Li (1-x)/2Ga (1-x)/2M xO (M Mg, Zn) prepared by high-pressure and high-temperature method has been studied by Raman scattering analysis. The LO Raman phonon in Li (...
Jiaqian Qin, Norimasa Nishiyama, Hiroaki Ohfuji, Toru Shinmei, Li Lei, Li Lei, Duanwei He, Tetsuo Irifune
Scripta Materialia   67 257-260   Aug 2012
The Vickers hardness of polycrystalline γ-boron (γ-B) was measured using a diamond indentation method. The elastic properties of polycrystalline γ-B were determined using an ultrasonic measurement method. Under a loading force of up to 20 N our te...
Hidemi Ishibashi, Hidemi Ishibashi, Hiroyuki Kagi, Haruko Sakuai, Hiroaki Ohfuji, Hirochika Sumino
American Mineralogist   97 1366-1372   Aug 2012
Carbonado, a variety of natural polycrystalline diamond whose origin remains unknown, differs notably in the properties from common diamonds of mantle origin. In this study, infrared spectroscopic and microscopic analyses were conducted on carbona...
Hiroaki Ohfuji, Shinsuke Okimoto, Takehiro Kunimoto, Futoshi Isobe, Hitoshi Sumiya, Kazuo Komatsu, Tetsuo Irifune
Physics and Chemistry of Minerals   39 543-552   Jul 2012
Nano-polycrystalline diamond (NPD) is a super-hard pure polycrystalline aggregate of nano-diamonds and has a characteristic microtexture composed of a mixture of granular and lamellar crystals. We investigated the origin of the unique microtexture...
D. Spengler, D. Spengler, D. Spengler, M. Obata, T. Hirajima, L. Ottolini, H. Ohfuji, A. Tamura, S. Arai
Journal of Petrology   53 1477-1504   Jul 2012
Serpentinized massif peridotite in the Xugou, Su-Lu ultrahigh-pressure (UHP) metamorphic belt, eastern China, preserves texturally old (porphyroclastic) ortho- and clinopyroxene with up to two generations of lamellae of garnet, clinopyroxene and M...
Yongtao Zou, Yongtao Zou, Tetsuo Irifune, Steeve Gréaux, Matthew L. Whitaker, Toru Shinmei, Hiroaki Ohfuji, Ryo Negishi, Yuji Higo
Journal of Applied Physics   112    Jul 2012
Elastic wave velocities of synthetic polycrystalline Mg 3Al 2(SiO 4) 3 garnet have been successfully measured to 20 GPa and temperatures up to 1700 K by ultrasonic interferometry combined with energy-dispersive synchrotron x-ray diffraction in a K...
M. Okayasu, Y. Ohkura, S. Takeuchi, S. Takasu, H. Ohfuji, T. Shiraishi
Materials Science and Engineering A   543 185-192   May 2012
The mechanical properties of an Al-Si-Cu alloy (ADC12), produced using various casting technologies, have been examined experimentally. Four different casting processes were employed, including gravity casting (GC), cold-chamber die-casting (CD), ...
Nobuhiro Settsu, Masafumi Matsushita, Manabu Takahashi, Masaki Tanimoto, Hiroaki Ohfuji
Zairyo/Journal of the Society of Materials Science, Japan   61 197-202   Feb 2012
The effects of brazing filler metal diffusion on the mechanical strength of a ceramic/metal composite are described. First, a specimen of a SUS304/Cu/Si 3N 4 system, including brazing filler metals of AgCu and/or AgCuTi, was prepared by brazing in...
M. Matsushita, S. Nakano, H. Ohfuji, I. Yamada, T. Kikegawa
Journal of Magnetism and Magnetic Materials   324 655   Feb 2012
Jiaqian Qin, Tetsuo Irifune, Haruhiko Dekura, Hiroaki Ohfuji, Norimasa Nishiyama, Li Lei, Toru Shinmei
Physical Review B - Condensed Matter and Materials Physics   85    Jan 2012
The phase relations in boron have been investigated at high pressure and high temperature using a multianvil apparatus, and the quenched sample has been analyzed by x-ray diffraction, Raman spectra, and transmission electron microscopy. We demonst...
OFUJI HIROAKI
岩石鉱物科学   41(1) 12-18 (J-STAGE)   2012
Junji Yamamoto, Junji Yamamoto, Kazuhiko Otsuka, Hiroaki Ohfuji, Hidemi Ishibashi, Hidemi Ishibashi, Naoto Hirano, Hiroyuki Kagi
European Journal of Mineralogy   23 805-815   Dec 2011
To assess the capacity of fluid inclusions in mantle minerals for CO 2 retention, annealing experiments were conducted for two mantle xenoliths with CO 2 inclusions for 8 days at 1000°C under atmospheric pressure and fO2 of 10 -11 MPa. The results...
Hide Yasuhara, Naoki Kinoshita, Hiroaki Ohfuji, Dae Sung Lee, Shinichiro Nakashima, Kiyoshi Kishida
Applied Geochemistry   26 2074-2088   Dec 2011
Examining the evolution of fracture permeability under stressed and temperature-elevated conditions, a series of flow-through experiments on a single rock fracture in granite has been conducted under confining pressures of 5 and 10. MPa, under dif...
Terumi Ejima, Masahide Akasaka, Hiroaki Ohfuji
Journal of Mineralogical and Petrological Sciences   106 246-254   Nov 2011
The oxidation state and distribution of Fe in olivine in a lherzolite xenolith from the Oku district, Oki-Dogo Islands, Japan, were investigated. A lherzolite xenolith collected from a volcanic neck of alkali olivine basalt contains olivine, ortho...
Shigeto Hirai, Yohei Kojima, Hiroaki Ohfuji, Norimasa Nishiyama, Tetsuo Irifune, Stephan Klemme, Geoffrey Bromiley, J. Paul Attfield
Physics and Chemistry of Minerals   38 631-637   Sep 2011
Raman spectroscopy and heat capacity measurements have been used to study the post-perovskite phase of CaIr0.5Pt0.5O3, recovered from synthesis at a pressure of 15 GPa. Laser heating CaIr0.5Pt0.5O3 to 1,900 K at 60 GPa produces a new perovskite ph...
Leiming Fang, Hiroaki Ohfuji, Toru Shinmei, Tetsuo Irifune
Diamond and Related Materials   20 819-825   May 2011
The stability and decomposition of graphitic C3N4 (g-C3N4) were studied in the pressure and temperature range of 10-25 GPa and up to 2000°C by multi-anvil experiments and phase characterization of the quenched products. g-C3N4 was found to remain ...
Steeve Gréaux, Norimasa Nishiyama, Yoshio Kono, Laurent Gautron, Hiroaki Ohfuji, Takehiro Kunimoto, Nicolas Menguy, Tetsuo Irifune
Physics of the Earth and Planetary Interiors   185 89-99   Apr 2011
High-pressure and high-temperature phase transformations of Ca3Al2Si3O12 grossular garnet were examined at 19-26GPa and 700-2000K using Kawai-type multi-anvil apparatus coupled with in situ X-ray diffraction (XRD). Recovered samples were analyzed ...
M. Matsushita, S. Nakano, H. Ohfuji, I. Yamada, T. Kikegawa
Journal of Magnetism and Magnetic Materials   323(6) 838-841   Mar 2011
We have investigated the pressure variation of the volume and structure of an FCC Fe64Mn36 anti-ferromagnetic Invar alloy. The inclination of the pressurevolume (PV) curve of the FCC structure becomes discontinuous at a pressure of 4 GPa. Accordin...
Li Lei, Tetsuo Irifune, Toru Shinmei, Hiroaki Ohfuji, Leiming Fang
Journal of Applied Physics   108    Oct 2010
Two new high-pressure phases of LiGaO2 have been discovered by direct compression of orthorhombic wurtzite-type LiGaO2 at pressures between 7 and 22 GPa and the temperatures of 25-2000 °C by means of the multianvil apparatus. The new intermediate ...
Yoshio Kono, Steeve Gréaux, Yuji Higo, Hiroaki Ohfuji, Tetsuo Irifune
Journal of Earth Science   21 782-791   Oct 2010
Simultaneous ultrasonic elastic wave velocity and in situ synchrotron X-ray measurements on grossular garnet were carried out up to 17 GPa and 1 650 K. P- and S-wave velocities and bulk and shear modulus showed linear pressure and temperature depe...
Ikuya Yamada, Ikuya Yamada, Yuka Takahashi, Kenya Ohgushi, Kenya Ohgushi, Norimasa Nishiyama, Ryoji Takahashi, Kohei Wada, Takehiro Kunimoto, Hiroaki Ohfuji, Yohei Kojima, Toru Inoue, Tetsuo Irifune
Inorganic Chemistry   49 6778-6780   Aug 2010
A novel A-site ordered perovskite CaCu3Pt4O 12 was synthesized under high pressure and high temperature of 12 GPa and 1250 °C. CaCu3Pt4O12 is the first perovskite in which the B site is fully occupied by Pt4+. The crystal structure refinement base...
MATSUSHITA MASAFUMI, NISHIMURA YUSUKE, OFUJI HIROAKI
銅と銅合金   49 56-60   Aug 2010
Hiroaki Ohfuji, Takuo Okuchi, Shoko Odake, Hiroyuki Kagi, Hitoshi Sumiya, Tetsuo Irifune
Diamond and Related Materials   in press 1040-1051   Jul 2010
Micrometer- to nanometer-scale structures of the cut surfaces of single- and polycrystalline diamonds by a pulsed ultraviolet laser have been thoroughly investigated by scanning and transmission electron microscopy. Within the laser-cut grooves, t...
H. Ohfuji, T. Okada, T. Yagi, H. Sumiya, T. Irifune
Journal of Physics: Conference Series   215    May 2010
Laser heating in a diamond anvil cell equipped with nano-polycrystalline diamond anvils (NPDAC) was tested for the first time. NPDAC was found to provide better heating efficiency than the standard DAC with single crystal anvils. This is probably ...
H. Ohfuji, T. Okada, T. Yagi, H. Sumiya, T. Irifune
High Pressure Research   30(1) 142-150   Mar 2010
Laser heating in diamond anvil cell (DAC) equipped with nano-polycrystalline diamond (NPD) anvils was tested for the first time using various types of lasers. An NPD-based DAC was found to provide better heating efficiency than a standard DAC with...

Research Grants & Projects

 
Ministry of Education, Culture, Sports, Science and Technology: Grants-in-Aid for Scientific Research(挑戦的萌芽研究)
Project Year: 2011 - 2013    Investigator(s): Junji YAMAMOTO
Dislocations provide a direct proof of plastic deformation of minerals. We observed dislocation structure around fluid inclusions in olivine and orthopyroxene. For olivine, development of edge dislocations with loop shape whose size is analogous t...
Ministry of Education, Culture, Sports, Science and Technology: Grants-in-Aid for Scientific Research(若手研究(B))
Project Year: 2011 - 2013    Investigator(s): Hiroaki OHFUJI
We performed a series of high pressure and high temperature experiments using a large-volume press to synthesize a pure, single-phase hexagonal diamond sintered body. Our study demonstrated that single-phase hexagonal diamond, which includes neith...
Ministry of Education, Culture, Sports, Science and Technology: Grants-in-Aid for Scientific Research(基盤研究(B))
Project Year: 2011 - 2013    Investigator(s): Jun-ichi ANDO
In this research, we observed the microstructures of both alpine-type peridotites and peridotite xenoliths in basalt, and analyzed the microchemistry around the dislocations developed in the olivine grains of the studied samples, using optical mic...
Ministry of Education, Culture, Sports, Science and Technology: Grants-in-Aid for Scientific Research(特別推進研究)
Project Year: 2008 - 2012    Investigator(s): Tetsuo IRIFUNE
Behaviors of iron and iron-bearing minerals have been studiedby both multianvil and diamond anvil cell experiments, in conjunction with ab initio calculations, under the pressure and temperature conditions from the deep lower mantle to the inner c...
Ministry of Education, Culture, Sports, Science and Technology: Grants-in-Aid for Scientific Research(基盤研究(A))
Project Year: 2008 - 2012    Investigator(s): Toru INOUE
Distribution of water in the Earth’s interiors and the effect of water for phase transition boundaries were clarified, and the water content in the Earth’s interior s was estimated by combining with the seismic data. Moreover, the studies for the ...
Ministry of Education, Culture, Sports, Science and Technology: Grants-in-Aid for Scientific Research(学術創成研究費)
Project Year: 2007 - 2012    Investigator(s): Hiroyuki KAGI
This research project aimed at developing neutron diffraction measurements at high pressure using a intense spallation neutron source at J-PARC and clarifying crystal structures of hydrogen-bearing materials in the deep earth, interior of planets,...
Ministry of Education, Culture, Sports, Science and Technology: Grants-in-Aid for Scientific Research(若手研究(B))
Project Year: 2008 - 2010    Investigator(s): Hiroaki OHFUJI
Laser heating in diamond anvil cell (DAC) equipped with nano-polycrystalline diamond (NPD) anvils was tested for the first time using various types of lasers. NPD-based DAC was found to provide better heating efficiency than a standard DAC with si...
Ministry of Education, Culture, Sports, Science and Technology: Grants-in-Aid for Scientific Research(基盤研究(B))
Project Year: 2006 - 2008    Investigator(s): Daisuke YAMAZAKI
Ministry of Education, Culture, Sports, Science and Technology: Grants-in-Aid for Scientific Research(特定領域研究)
Project Year: 2004 - 2008    Investigator(s): 入舩 徹男, Norimasa NISHIYAMA
Ministry of Education, Culture, Sports, Science and Technology: Grants-in-Aid for Scientific Research(学術創成研究費)
Project Year: 2003 - 2007    Investigator(s): Tetsuo IRIFUNE
Technical developments have been made in producing higher pressures in multianvil apparatus using sintered diamond (SD) anvils and also for precise measurements of sound velocities of high-pressure phases under the P/T conditions of the mantle tra...
Ministry of Education, Culture, Sports, Science and Technology: Grants-in-Aid for Scientific Research(基盤研究(B))
Project Year: 2003 - 2006    Investigator(s): Toru INOUE
We have clarified the physical properties of deep Earth mantle minerals and the effect of water. Experiments were conducted by in situ X-ray measurements in addition to quench experiments.From our previous studies, it has been clarified that high ...