Precise measurement of diffusion coefficient in semiconductor melt under strong magnetic field
| Project/Area Number |
13650806
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Metal making engineering
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| Research Institution | The Institute of Space and Astronautical Science |
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Principal Investigator |
INATOMI Yuko The Institute of Space and Astronautical Science, Space Utilization Research Center, Associate Professor, 宇宙基地利用研究センター, 助教授 (50249934)
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| Co-Investigator(Kenkyū-buntansha) |
KURIBAYASHI Kazuhiko The Institute of Space and Astronautical Science, Research Division for Space Transportation, Professor, 宇宙輸送研究系, 教授 (70092195)
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| Project Period (FY) |
2001 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2002: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | Diffusion coefficient / Strong magnetic field / Convection / Semiconductor melt / Space experiment / Hard sphere model / In-Sn / Ga-doped Ge |
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| Research Abstract |
In the present study, diffusion coefficients in semiconductor melt were measured precisely by utilization of a strong static magnetic field from the melting point of the specimen to 1500 K and then the measured data were compared with those obtained in the microgravity environment and with the estimated values by a hard sphere model.
Some experimental conditions for diffusion experiment in a static magnetic field were derived by a numerical simulation based of a fine element method. Based on the numerical result, the diffusion experiments for In-Sn, Ga-doped Ge, Ge-Si and In_*Ga_<1*>As melts were performed using an image furnace in a static magnetic field. The obtained results for the inter-diffusion coefficients were as follows.
1. InSn : The obtained coefficients near the melting point agreed well with those estimated by a hard sphere model However, the temperature dependency of the experimental values at high temperature was almost same as the space experiment result. The physical model for diffusion process in a so-called "simple liquid" should be modified based on the experimental data obtained in higher temperature.
2. Ga-doped Ge and Ge-Si : The obtained coefficients were much higher than those estimated by the hard sphere model. The results supports validity of the Itami's model which assumes molten Ge has a structure with a weak covalent bonding between the molecules.
3. In_*Ga_<1*>As : No reliable data was obtained by the present method due to the segregation of the solute species, because die segregation coefficient was large in the pseude-binary phase diagram. A shear cell method with an application of strong static magnetic field is a promising way to improve reliability of the experimental data in the case of alloy with a large segregation coefficient.
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Report
(3 results)
Research Products
(10 results)
