JAEA
  • help
  • PC | SP
  • JP | EN
          
Refine your search：     
Report No.
 - 
Clear All
Search Results: Records 1-15 displayed on this page of 15
  • 1

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

${it In situ}$ X-ray observations of the diamond formation process in the C-H$$_{2}$$O-MgO system

Okada, Taku; Utsumi, Wataru; Shimomura, Osamu

Journal of Physics; Condensed Matter, 14(44), p.11331 - 11335, 2002/11

https://doi.org/10.1088/0953-8984/14/44/477
 Times Cited Count：5 Percentile：29.64(Physics, Condensed Matter)

In order to clarify the mechanism of diamond formation in the Earth's mantle, we studied the diamond formation in the H$$_{2}$$O-fluid by in situ X-ray observation with the simple C-H$$_{2}$$O-MgO system. The results suggest that the solubility of MgO component increases greatly as a function of pressure. However, the generation of fluid is not a sufficient condition for diamond formation, because the carbon quantity in fluid is not increased drastically until just before the diamond formation temperature. This is the first report of the kinetics study in fluid using synchrotron radiation.

Journal Articles

In situ X-ray observations of the decomposition of brucite and the graphite-diamond conversion in aqueous fluid at high pressure and temperature

Okada, Taku; Utsumi, Wataru; Kaneko, Hiroshi*; Yamakata, Masaaki*; Shimomura, Osamu

Physics and Chemistry of Minerals, 29(7), p.439 - 445, 2002/08

https://doi.org/10.1007/s00269-002-0254-6
 Times Cited Count：18 Percentile：53.87(Materials Science, Multidisciplinary)

An experimental technique to make real-time observations at high pressure and temperature of the diamond forming process in candidate material of mantle fluids as a catalyst has been established for the first time. In situ X-ray diffraction experiments using synchrotron radiation have been performed upon a mixture of brucite (Mg(OH)$$_{2}$$) and graphite as starting material. Brucite decomposes into periclase (MgO) and H$$_{2}$$O at 3.6 GPa and 1050$$^{circ}$$C while no periclase is formed after the decomposition of brucite at 6.2 GPa and 1150$$^{circ}$$C, indicating that the solubility of the MgO component in H$$_{2}$$O greatly increases with increasing pressure. The conversion of graphite to diamond in aqueous fluid has been observed at 7.7 GPa and 1835$$^{circ}$$C. Time-dependent X-ray diffraction profiles for this transformation have been successfully obtained.

Journal Articles

${it In situ}$ X-ray observation of cubic BC$$_{2}$$N formation under high pressures and temperatures

Utsumi, Wataru; Okada, Taku; Funakoshi, Kenichi*; Shimomura, Osamu

Proceeding of the 8th NIRIM International Symposium on Advanced Materials (ISAM 2001), p.39 - 40, 2001/03

no abstracts in English

Journal Articles

Construction of laser-heated diamond anvil cell system for ${it in situ}$ X-ray diffraction study at SPring-8

Watanuki, Tetsu; Shimomura, Osamu; Yagi, Takehiko*; Kondo, Tadashi*; Isshiki, Maiko*

Review of Scientific Instruments, 72(2), p.1289 - 1292, 2001/02

https://doi.org/10.1063/1.1343869
 Times Cited Count：82 Percentile：93.69(Instruments & Instrumentation)

no abstracts in English

Journal Articles

Second-order phase transition of FeS under high pressure and temperature

Kusaba, Keiji*; Utsumi, Wataru; Yamakata, Masaaki*; Shimomura, Osamu; Shono, Yasuhiko*

Journal of Physics and Chemistry of Solids, 61(9), p.1483 - 1487, 2000/09

https://doi.org/10.1016/S0022-3697(00)00005-6
 Times Cited Count：8 Percentile：43.53(Chemistry, Multidisciplinary)

no abstracts in English

Journal Articles

A First-order liquid-liquid phase transition in phosphorus

Katayama, Yoshinori; Mizutani, Takeshi*; Utsumi, Wataru; Shimomura, Osamu; Yamakata, Masaaki*; Funakoshi, Kenichi*

Nature, 403(6766), p.170 - 173, 2000/01

https://doi.org/10.1038/35003143
 Times Cited Count：781 Percentile：98.05(Multidisciplinary Sciences)

no abstracts in English

Journal Articles

A New cubic anvil press with radial slit system at the SPring-8

Yamakata, Masaaki*; Mizutani, Takeshi; Utsumi, Wataru; Katayama, Yoshinori; Shimomura, Osamu

Science and Technology of High Pressure (Proceedings of AIRAPT-17), p.1109 - 1112, 2000/00

no abstracts in English

Journal Articles

Optical ionization of DX center in AlGaAs:Se by inner-shell excitation

Yoshino, Yoko; Takarabe, Kenichi*; Ishii, Masashi*; Katayama, Yoshinori; Shimomura, Osamu

Physica B; Condensed Matter, 273-274, p.781 - 783, 1999/12

https://doi.org/10.1016/S0921-4526(99)00648-1
 Times Cited Count：1 Percentile：8.23(Physics, Condensed Matter)

DX state is strongly localized. This nature could be investigated by observing relaxation process of localized electrons to emptied inner shells. We have found two different optical ionization process of the DX center in Al$$_{x}$$Ga$$_{1-x}$$As:Se (x=0.33,$$N_{rm Se}=5times10^{17}$$(cm$$^{-3}$$)) by using synchrotron radiation. They are tentatively assigned to be a direct lift of an inner-shell electron to the conduction band (CB) followed by a capture of an electron at the DX center to the emptied inner shell $$({rm DX}^{-}+hnu ({rm L,} $$K-edge$$)rightarrow {rm DX}^{0}+e_{rm CB})$$ and the Auger ionization of one electron of the DX center to the CB followed by a capture of another electron to the emptied inner shell $$({rm DX}^{-}+hnu ({rm L,} $$K-edge$$)rightarrow {rm DX}^{+}+e_{rm CB}+e_{rm vacuum})$$.

Journal Articles

In situ X-ray observation of graphite-diamond transition using carbonate catalysts under high pressures and high temperatures

Utsumi, Wataru; Taniguchi, Takashi*; Mizutani, Takeshi; Nishiyama, Norimasa*; Nakano, Satoshi*; Funakoshi, Kenichi*; Shimomura, Osamu

Proceedings of the 6th NIRIM International symposium on Advanced Materials (ISAM99), p.67 - 68, 1999/03

no abstracts in English

Journal Articles

High temperature research beamline (BL04B1) at SPring-8

Utsumi, Wataru; Funakoshi, Kenichi*; Urakawa, Satoru*; Irifune, Tetsuo*; Tamura, Kozaburo*; Inui, Masanori*; Tsuji, Kazuhiko*; Shimomura, Osamu

Hoshako, 12(1), p.17 - 23, 1999/02

http://ci.nii.ac.jp/naid/10002497358

no abstracts in English

Journal Articles

Structure of liquid rubidium and liquid sodium under pressure

Morimoto, Yoshiki*; Kato, Sayuri*; Toda, Naohiro*; Katayama, Yoshinori; Tsuji, Kazuhiko*; Yaoita, Kenichi*; Shimomura, Osamu

Review of High Pressure Science and Technology, 7, p.245 - 247, 1998/03

http://ci.nii.ac.jp/naid/10002689633

X-ray diffraction for liquid Rb and liquid Na has been measured under pressure up to 6 GPa using synchrotron radiation. Volume dependences of static structure factor $$S(Q)$$ and pair distribution function $$g(r)$$ were obtained to the volume range $$nu(=V/V_{0})$$ of 0.52 for liquid Rb and $$nu$$ of 0.73 for liquid Na to investigate the effect of the electronic change on the structure of liquid metals. With increasing pressure, the peaks of $$S(Q)$$ of both liquid Rb and liquid Na shift towards higher $$Q$$, and the heights of the first peak increase. Theses volume dependences of the structural data are compared with those for other metals under pressure and expanded fluids.

Journal Articles

X ray diffraction measurements in a double-stage multianvil apparatus using ADC anvils

Irifune, Tetsuo*; Kuroda, Koji*; Nishiyama, Norimasa*; Inoue, Toru*; Funamori, Nobumasa*; Uchida, Takeyuki*; Yagi, Takehiko*; Utsumi, Wataru; Miyajima, Nobuyoshi*; Fujino, Kiyoshi*; et al.

Geophysical Monograph 101 (Properties of Earth and Planetary Materials at High Pressure and Temperature), p.1 - 8, 1998/00

no abstracts in English

Journal Articles

Density measurements of liquid under high pressure and high temperature

Katayama, Yoshinori; Tsuji, Kazuhiko*; Shimomura, Osamu; Kikegawa, Takumi*; M.Mezouar*; D.Martinez-Garcia*; J.M.Besson*; D.Haeusermann*; M.Hanfland*

Journal of Synchrotron Radiation, 5(Part3), p.1023 - 1025, 1998/00

no abstracts in English

Journal Articles

In-situ X-ray observation of phase transformation of rhombohedral boron nitride under static high pressure and high temperature

Taniguchi, Takashi*; Sato, Masashi*; Utsumi, Wataru; Kikegawa, Takumi*; Shimomura, Osamu

Diamond and Related Materials, 6(12), p.1806 - 1815, 1997/12

https://doi.org/10.1016/S0925-9635(97)00143-X
 Times Cited Count：20 Percentile：72.83(Materials Science, Multidisciplinary)

no abstracts in English

Journal Articles

Effect of nonhydrostaticity on the pressure induced phase transformation of rhombohedral boron nitride

Taniguchi, Takashi*; Sato, Masashi*; Utsumi, Wataru; Kikegawa, Takumi*; Shimomura, Osamu

Applied Physics Letters, 70(18), p.2392 - 2394, 1997/05

https://doi.org/10.1063/1.118882
 Times Cited Count：25 Percentile：74.04(Physics, Applied)

no abstracts in English

15 (Records 1-15 displayed on this page)
  • 1