| Autor: |
Fujita, Isao, Kishimoto, Kengo, Sato, Masaya, Anno, Hiroaki, Koyanagi, Tsuyoshi |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 5/1/2006, Vol. 99 Issue 9, p093707, 8p, 2 Charts, 11 Graphs |
| Abstrakt: |
Polycrystalline samples of Sr8GaxGe46-x clathrates with varied nominal Ga contents were prepared by powder metallurgy to produce n-type samples with carrier concentration n of 1.8×1020–1.1×1021 cm-3. Their thermoelectric properties were measured in the temperature range from 300 to 900 K. Their Seebeck coefficient and electrical conductivity were found to be typical for a heavily doped semiconductor, and varied systematically with their carrier concentration. The maximum value of the figure-of-merit ZT was 0.62 at 800 K for n=5.6×1020 cm-3. Other following properties were also measured or estimated, and their relationships with the thermoelectric properties are discussed. The band gap of the samples was estimated to be 0.4–0.5 eV; their effective mass was an almost constant value of 3.1me at room temperature, and this value decreases with increasing temperature; and their electron Hall mobilities were 8–13 cm2 V-1 s-1 at room temperature, increasing slightly with decreasing carrier concentration. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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