| Project/Area Number |
09650918
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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 |
無機工業化学
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| Research Institution | MURORAN INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
SAKAKI Makoto MURORAN INSTITUTE OF TECHNOLOGY,FACULTY OF ENGINEERING,ASSOCIATE PROFESSOR, 工学部, 助教授 (70187128)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 1998: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1997: ¥2,800,000 (Direct Cost: ¥2,800,000)
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| Keywords | Precursor / Mo-Si-C-N Ceramics / Heat element / Molybdenum silicide / Silicon carbide / Seebeck coefficient / Electrical conductivity / Thermoelectric material / ゼーベック係数 / 有機高分子前駆体法 / Mo-Si-Cセラミックス / 非晶質 / アンモノリシス / 耐食性 / C / Cコンポジット / コーティング |
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| Research Abstract |
Amorphous Mo-Si-C-N ceramics were prepared at 1273 K for 10 h in Ar by heating of polysilazane with molybdenum powder in the composition range from 5 to 30 wt%. By a secondary heat treatment of the Mo-Si-C-N at 1773 K for 2 h in Ar, several composition range of MoSi_2-SiC ceramic composites were obtained. The crystalline sizes of the MoSi_2 and SiC ranged around several tens nanometers. MoSi_2-SiC composites obtained from 5 or 15 wt% Mo-containing polysilazane were semiconductive. However, MoSi_2-SiC composites obtained from 20 or 30 wt%Mo-containing polysilazane showed metallic character. All types of the MoSi_2-SiC composites have n-type carrier measured by Seebeck coefficient. The absolute values of the Seebeck coefficients of the composites increased with increasing MoSi_2 content. Nitrogen content in the composites increased with decreasing MoSi_2 content.. This means that nitrogen in the SiC as a matrix of the composites decreased with increasing MoSi_2 content as a result of the accelerating of reaction sintering. MoSi_2-SiC composites obtained are attractive to use as heat element because of the superior oxidation resistance, lower conductivity coefficient vs. temperature, and smaller crystal-line size. And also the fine-grained MoSi_2-SiC composites are candidate as thermoelectric material evaluated by higher power factor of the electrical properties of the composites.
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