Relaxation Phenomena on Glass Transition and its Pressure Dependence
| Project/Area Number |
04640357
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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 | The Nishi Tokyo University |
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Principal Investigator |
KOGURE Yoshiaki The Nishi Tokyo University Department of Materials Associate Professor, 理工学部, 助教授 (20016124)
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| Co-Investigator(Kenkyū-buntansha) |
DOYAMA Masao The Nishi Tokyo University Department of Materials Professor, 理工学部, 教授 (40010748)
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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 |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1993: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1992: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Glass transition / Relaxation phenomena / Superionic conductor / Hot wire method / Ultrasound / Interatomic Potential / ガラス / 熱活性化過程 / 内部摩擦測定 |
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| Research Abstract |
Thermal and Ultrasonic Measurements of (AgI)_x(AgPO_3)_<1-x> at Glass Transition
The superionic conducting glass (AgI)_x(AgPO_3)_<1-x> shows glass transition around 100ﾟC, and is a suitable material for the present study. We have develpped the "multicurrent" transient hot-wire method for the simulataneous measurements of the thermal conductivity and the thermal diffusivity of materials. The method was applied to (AgI)_x(AgPO_3)_<1-x>, (chi = 0 and 0.5) at temperatures between 20 and 200ﾟC.The thermal conductivity showed abnormalous increase at glass transition temperature, wheras the thermal diffusivity showed normal behaviors at the temperature. From these results it can be concluded that the cbserved effect in thermal conductivity can be attributed to the change of the specific heat at the glass transition. On the otherhand, the ultrasonic mesurement under the hydorostatic pressure to investigate the mechanical relaxation phenomena is in progress. A new specimen cell and a computer co
… More
ntrolling system for the ultrasonic measurement at the glass transition temperature have been developed. The elastic constants and the mechanical loss of the specimens can be measured as a function of the temperature and the sound frequency.
Computer Simulation of the Glass Transition
A number of study based on the computer simulation on the atomic structure of glass state has been repoted. The dynamics and the reluxation phenomena of atoms can be studied by means of the molecular dynamics simuration, but it may take a large CPU time for the simulation of glass transition and no systematic research has not yet done. The development of simple interatomic potential is desired to perform the simulations in a limitted CPU time. We have developed a new potential function based on the embedded atom method and the determined potential parameters were examined through the elastic anharmonicity, the phonon dispersion relation, stacking fault energy, and other material properties. The potential is going to be used for the simulations of the glass transition. Less
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Report
(3 results)
Research Products
(20 results)
