| Project/Area Number |
63460095
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Thermal engineering
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| Research Institution | Institute of Industrial Science, University of Tokyo |
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Principal Investigator |
TANASAWA Ichiro University of Tokyo, Inst. of Ind. Sci., Professor, 生産技術研究所, 教授 (30013105)
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| Co-Investigator(Kenkyū-buntansha) |
MAEKAWA Tohru Toyo University, Mech. Engng, Associate Professor, 工学部, 助教授 (40165634)
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| Project Period (FY) |
1988 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥5,800,000 (Direct Cost: ¥5,800,000)
Fiscal Year 1989: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1988: ¥4,000,000 (Direct Cost: ¥4,000,000)
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| Keywords | Heat Transfer / Convective Flow / Materials Processing / Single Crystal / Czochralski Growth / Melt Growth / チョクラスキー法 / 引上げ凝固法 |
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| Research Abstract |
In the first year of this two-year project, an experiment was conducted, using a.glass container which modeled the Czochralski crusible, to observe the heat and fluid flow during the process. The distribution of flow and temperature in the container was visualized microcapsulated liquid crystal suspended in the liquid. As the result, it was found that the flow and the temperature of the liquid oscillate periodically when the parameters, such as the rotation rates of crystal and container, the temperature difference between the wall of the container and the liquid-solid interface and the thermophysical properties of melt, were within a certain range. Numerical simulation by a super-computer revealed that quite similar phenomena occurred even if the boundary conditions were axisymmetric. These results suggest that the growth striations observed in the single crystal grown by the Czochralski method are due to the oscillatory flow in the melt.
In the second year the effect of external magnetic field for damping the oscillatory flow in the Czochralski melt was investigated. As a result of analysis on the effect of magnetic field on natural convection, the flow velocity of the melt is decreased rapidly by magnetic field when its intensity exceeds a certain critical value. Also a numerical analysis was carried out to reveal the effect of magnetic field on the growth process of gallium-arsenide(GaAs). It was found that the magnetic field damped the fluctuation of flow completely if the intensity was sufficient.
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