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Shimojo, Fuyuki*; Miyata, Yasuhisa*; Sugahara, Takayuki*; Hattori, Takanori; Tsuji, Kazuhiko*
Journal of Physics; Conference Series, 98, p.042016_1 - 042016_4, 2008/00
Times Cited Count：0 Percentile：0.05(Metallurgy & Metallurgical Engineering)The structural and bonding properties of liquid InAs under pressure are investigated by ab initio molecular-dynamics simulations. The calculated structure factors are in good agreement with the recent X-ray diffraction measurements over a wide range of pressure. It is shown that the pressure dependence of the spatial correlation between atoms depends on the species of atomic pairs reflecting the strength of the covalent bonding. A detailed investigation of the pair distribution functions confirms that different pressure-induced structural changes occur below and above 6-10 GPa. It is suggested that such structural changes are related to the reduction of the covalent nature under pressure.
Hattori, Takanori; Tsuji, Kazuhiko*; Miyata, Yasuhisa*; Sugahara, Takayuki*; Shimojo, Fuyuki*
Physical Review B, 76(14), p.144206_1 - 144206_10, 2007/10
Times Cited Count：6 Percentile：31.25(Materials Science, Multidisciplinary)To understand the pressure-induced structural changes of liquid III-V compounds systematically, the pressure dependence of liquid InAs was investigated using the synchrotron X-ray diffraction and an 
molecular dynamics simulation (AIMD). The X-ray diffraction experiments revealed that the liquid changes its compression behavior from a nearly uniform type to a nonuniform one around 9 GPa. Corresponding to this change, the coordination number CN, which is maintained up to 9 GPa, markedly increases from 6.0 to 7.5. The AIMD simulation revealed that this change is related to the change in the pressure dependence of all three pair correlations. In particular, a marked change is observed in the As-As correlation; in the low pressure region the position of the first peak in 
, 
, increases with maintaining the CN
, but in the high pressure region the stops increasing and the CN begins to increase. The results for InAs are compared with those for GaSb and InSb and the systematics of the pressure-induced structural change of liquid III-V compounds are dicussed.
Hattori, Takanori; Yagafarov, O.*; Katayama, Yoshinori; Chiba, Ayano*; Sano, Asami; Inamura, Yasuhiro; Otomo, Toshiya*; Matsuzaki, Yuki*; Shimojo, Fuyuki*
no journal, ,
PLANET is the beamline dedicated for the high-pressure experiments. The operation has been started at JFY 2013, and now many users are coming to use. In this talk, we introduce the current state of the PLANET and the example of the structure analysis of disordered materials. PLANET adopted the double staged compression system of the multi anvil 6-6, and enables the data collation at 10 GPa and 2000 K. To extend accessible PT range, we newly introduce another compression system of multi-anvil 6-8, and succeeded in generating 16 GPa and 1273 K. In addition, the PLANET is designed so that we can analyze the structure of liquid under pressure. In the analysis, the program for liquid analysis developed at BL21 NOVA is used. Here, we briefly introduce the reliability of the results and the pressure evolution of the silica glass.
Hattori, Takanori; Yagafarov, O.*; Katayama, Yoshinori; Chiba, Ayano*; Sano, Asami; Inamura, Yasuhiro; Otomo, Toshiya*; Matsuzaki, Yuki*; Shimojo, Fuyuki*
no journal, ,
PLANET is the beamline dedicated for the high-pressure experiments. The operation has been started at JFY 2013, and now many users are coming to use. In this talk, we introduce the current state of the PLANET and the example of the structure analysis of disordered materials. PLANET adopted the double staged compression system of the multi anvil 6-6, and enables the data collation at 10 GPa and 2000 K. To extend accessible PT range, we newly introduce another compression system of multi-anvil 6-8, and succeeded in generating 16 GPa and 1273 K. In addition, the PLANET is designed so that we can analyze the structure of liquid under pressure. In the analysis, the program for liquid analysis developed at BL21 NOVA is used. Here, we briefly introduce the reliability of the results and the pressure evolution of the silica glass.
Hattori, Takanori; Yagafarov, O.*; Katayama, Yoshinori; Chiba, Ayano*; Sano, Asami; Inamura, Yasuhiro; Otomo, Toshiya*; Matsuzaki, Yuki*; Shimojo, Fuyuki*
no journal, ,
We recently constructed the diffractometer dedicated to high-pressure purpose at pulsed neutron source J-PARC. This beamline has the huge 6-axis multi-anvil press, which is good at generating high-pressure and high-temperature condition simultaneously. By developing devices to eliminate scattering from materials around the sample, such as a sample container, a heater, we can obtain very clear pattern even under high-PT condition. This enables us to analyze the PT dependence of the structure of amorphous solids and liquids with high quality. I will explain the performance of the beamline and the PT modification of SiO
glass.
