1999 Fiscal Year Final Research Report Summary
Improvement Mechanism of Thermoelectric Materials by Dispersion of Fine Particles.
| Project/Area Number |
09450273
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Material processing/treatments
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| Research Institution | Osaka University |
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Principal Investigator |
NAGAI Hiroshi Materials Sci. and Proc. Osaka University, Professor, 大学院・工学研究科, 教授 (80029206)
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| Co-Investigator(Kenkyū-buntansha) |
ITO Mikio Materials Sci. and Proc. Osaka University, Research Assitant, 大学院・工学研究科, 助手 (00294033)
KATSUYAMA Shigeru Materials Sci. and Proc. Osaka University, Research Assitant, 大学院・工学研究科, 助手 (00224478)
MAJIMA Kazuhiko Materials Sci. and Proc. Osaka University, Associate Prof., 大学院・工学研究科, 助教授 (60029270)
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| Project Period (FY) |
1997 – 1999
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| Keywords | Thermoelectric materials / mechanical alloying / nano-composite / thermoelectric power / electrical resistivity / thermal conductivity / powder metallurgy / sintered materials |
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| Research Abstract |
The performance of the thermoelectric materials is represented by the figure of merit Z : Z=αィイD12ィエD1/ρκ, where α is Seebeck coefficient, ρ is electrical resistivity, and κ is thermal conductivity. In order to obtain a high figure of merit, a large Seebeck coefficient and low electrical resistivity is required, as well as a low thermal conductivity. The effects of dispersion of fine particles on the thermoelectric propeties are investigated in this study.
The results obtained are as follows :
(1)Thermoelectric materials (β-FeSiィイD22ィエD2 and CoSbィイD23ィエD2) with dispersion of fine particles are obtained by mechanical alloying (MA) and hot-pressing method. (2) β-FeSiィイD22ィエD2 with ultra-fine SiC dispersion was obtained by MA of FeSiィイD22ィエD2, Si and C powders. The performance was markedly improved by decreasing the thermal conductivity. (3) Electrical resitivity and thermal conductivity of CoSbィイD23ィエD2 were markedly decreased by the dispersion of FeSbィイD22ィエD2 and NiSbィイD22ィエD2 particles with low resistivity. (4) Hall effect measurements revealed that dispersion of second phases differently affects the thermoelectric properties of n-type and p-type materials due to the electronic interaction between the matrix and the second phases.
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