| Project/Area Number |
04640348
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
固体物性
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
TAKEDA Shin'ichi Kyushu University, Department of Physics, College of General Ecudation, Professor, 教養部, 教授 (10111733)
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| Co-Investigator(Kenkyū-buntansha) |
UECHI Tetsuo Kyushu University, Department of Physics, College of General Education, Associat, 教養部, 助教授 (80038463)
INUI Masanori Kyushu University, Department of Physics, College of General Education, Research, 教養部, 助手 (40213136)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1993: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1992: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Liquid metal, Alloy / Partial Structure / Dynamics / Molten Salts / miscibility gap / ultrasonic velocity / Ionic Liquid / ion-electron correlation / 液体金属.合金 / 溶融ハロゲン化銅 / 溶融ハロゲン化銀 / イオン性 / 電子-イオン相関 / 液体金属,合金 / 構造 / 二相分離 |
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| Research Abstract |
The ultrasonic velocity, sound attenuation and density measurements have been carried out for molten Cu(Cl_<1-x>Br_x) mixtures to investigate the thermodynamic and dynamical properties. The adiabatic compressibility of this system was obtained from the observed ultrasonic velocity and density. The observed compressibility has the maximum value around Cu(Cl_<0.2>Br_<0.8>), which suggests large fluctuaion in the molten salt mixtures. The sound attenuation shows large temperature dependence around the same composition.
EXAFS measurement for molten CuX(X=Cl, Br) and agX(X=Cl, I) has been carried out near the melting temperature to study the partial structure. The obtained Cu-halogen and Ag-halogen distances are about 0.1A-0.2A shorter than the distances obtained from neutron deffraction measurement by isotopic substitution method and the results suggest the cluster formation such as a CuX(X=Cl, Br) and AgX(X=Cl, I) trimmer in the liquid state.
Neutron diffraction, ultrasonic velocity and den
… More
sity measurements have been carried out for liquid Bi-Ga alloys along the liquidus curve and at temperatures above the critical point where the miscibility gap closes. A remarkable change in the structure factor has been observed at the critical concentration, and the temperature coefficient of the adiabatic compressibility shows rather small value above the miscibility gap region. This suggests that the spatial fluctuation due to the thermal agitation does not affect the compressibility in the miscibility gap region, and the atoms can easily be rearranged to have the preferable structure with smaller spatial fluctuations.
The structure factors of liquid Te at 470C and 570C have been measured by X-ray and neutron diffraction. The ion-electron correlation function and valence electron distribution were evaluated from this difference at the two temperatures. The obtained charge distribution function shows two peaks at the distance around 0.8A and 1.7A just above the melting temperature. Those correspond to the distribution of the lone pair electrons and the covalent bonded electrons around a central tellurium ion, respectively. At 570C, single peak is observed at the distance around 1.1A in the electron charge distribution. This corresponds to the change of the local charge density distribution from non-metalllic state to metallic one in liquid Te. Less
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