| Autor: |
Yamashita, Osamu, Satou, Kouji, Odahara, Hirotaka, Tomiyoshi, Shoichi |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 10/1/2005, Vol. 98 Issue 7, p073707, 8p, 1 Black and White Photograph, 2 Diagrams, 1 Chart, 7 Graphs |
| Abstrakt: |
The resultant thermoelectric figure of merit ZT of M/T/M (M=Cu or Ni and T=Bi0.88Sb0.12) composite materials welded with Bi–Sb alloy was measured at 298 K as a function of relative thickness of Bi–Sb alloy and compared with ZT values calculated by treating it as an electrical and thermal circuit. It was first clarified experimentally that the observed ZT values of composite materials have a local maximum at an optimum volume fraction (corresponding to the thickness) of Bi–Sb alloy in spite of macroscopic composite materials, owing to a significant enhancement in the Seebeck coefficient. It is sure that the enhancement in α is caused by the boundary Seebeck coefficient generated at the interface between Bi–Sb alloy and a metal. It was thus clarified that the interface effect appears clearly in macroscopic systems. The observed maximum ZT values at 298 K reached a surprisingly great value of 0.44 at a relative thickness of approximately 0.7, which corresponds to approximately 1.7 times as large as 0.26 of Bi0.88Sb0.12 alloy and to about half of 0.8–0.9 of commercially utilized bismuth telluride compounds. So enhanced ZT may not be utilizable for a Peltier module, but is available for generators. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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