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Katayama, Yoshinori; Inamura, Yasuhiro*; Mizutani, Takeshi*; Yamakata, Masaaki*; Utsumi, Wataru; Shimomura, Osamu*
Science, 306(5697), p.848 - 851, 2004/10
Times Cited Count:148 Percentile:96.71(Multidisciplinary Sciences)Structural transformation between two liquid structures of phosphorus that occurred at about 1 GPa and 1000C was investigated by in-situ X-ray radiography. When the low-pressure liquid was compressed, dark and round objects appeared in the radiograph. X-ray diffraction measurements confirmed that these objects were the high-pressure liquid. The drops grew and eventually filled the sample space. Decompressing caused the reverse process. The macroscopic phase separation supported the view that it was a first-order liquid-liquid phase transition. X-ray absorption measurements revealed that the change in density at the transition is about 40 % of the density of the high-pressure liquid.
Okada, Taku; Utsumi, Wataru; Kaneko, Hiroshi*; Yamakata, Masaaki*; Shimomura, Osamu
Physics and Chemistry of Minerals, 29(7), p.439 - 445, 2002/08
Times Cited Count:18 Percentile:53.64(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)) and graphite as starting material. Brucite decomposes into periclase (MgO) and HO at 3.6 GPa and 1050C while no periclase is formed after the decomposition of brucite at 6.2 GPa and 1150C, indicating that the solubility of the MgO component in HO greatly increases with increasing pressure. The conversion of graphite to diamond in aqueous fluid has been observed at 7.7 GPa and 1835C. Time-dependent X-ray diffraction profiles for this transformation have been successfully obtained.
Goto, Shunji*; Ohashi, Haruhiko*; Takeshita, Kunikazu*; Yabashi, Makina*; Yamakata, Masaaki*; Asano, Yoshihiro; Ishikawa, Tetsuya*
Nuclear Instruments and Methods in Physics Research A, 467-468(Part1), p.813 - 815, 2001/07
Times Cited Count:3 Percentile:28.27(Instruments & Instrumentation)no abstracts in English
Kusaba, Keiji*; Utsumi, Wataru; Yamakata, Masaaki*; Shimomura, Osamu; Shono, Yasuhiko*
Journal of Physics and Chemistry of Solids, 61(9), p.1483 - 1487, 2000/09
Times Cited Count:7 Percentile:41.12(Chemistry, Multidisciplinary)no abstracts in English
Utsumi, Wataru; Katayama, Yoshinori; Mizutani, Takeshi; Shimomura, Osamu; Yamakata, Masaaki*; Azuma, Masaki*; Saito, Takashi*
Nihon Kessho Gakkai-Shi, 42(1), p.59 - 67, 2000/02
no abstracts in English
Katayama, Yoshinori; Mizutani, Takeshi*; Utsumi, Wataru; Shimomura, Osamu; Yamakata, Masaaki*; Funakoshi, Kenichi*
Nature, 403(6766), p.170 - 173, 2000/01
Times Cited Count:738 Percentile:98.15(Multidisciplinary Sciences)no abstracts in English
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
Mizutani, Takeshi; Katayama, Yoshinori; Utsumi, Wataru; Funakoshi, Kenichi*; Yamakata, Masaaki*; Shimomura, Osamu
Science and Technology of High Pressure (Proceedings of AIRAPT-17), p.525 - 528, 2000/00
no abstracts in English
Utsumi, Wataru; Funakoshi, Kenichi*; Urakawa, Satoru*; Yamakata, Masaaki*; Tsuji, Kazuhiko*; Konishi, Hiroyuki; Shimomura, Osamu
Review of High Pressure Science and Technology, 7, p.1484 - 1486, 1998/00
no abstracts in English
Yamakata, Masaaki*; Yagi, Takehiko*
Review of High Pressure Science and Technology, 7, p.107 - 109, 1998/00
no abstracts in English