Improved thermoelectric performance of (Zr0.3Hf0.7)NiSn half-Heusler compounds by Ta substitution
| Autor: | Anke Weidenkaff, Jürg Hulliger, Krzysztof Gałązka, Wenjie Xie, Songhak Yoon, Gesine Saucke, Sascha Populoh |
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| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | Galazka, Krysztof; Populoh, S; Xie, W; Yoon, S; Saucke, G; Hulliger, Jürg; Weidenkaff, Anke (2014). Improved thermoelectric performance of (Zr0.3Hf0.7)NiSn half-Heusler compounds by Ta substitution. Journal of applied physics, 115(183704), pp. 1-8. American Institute of Physics 10.1063/1.4874798 |
| ISSN: | 1089-7550 0021-8979 |
| Popis: | The thermoelectric performance of Ta substituted (ZrHf)NiSn-based half-Heusler compounds is studied. Here, Ta is used on the Hf site for controlling the charge carrier concentration in contrast to the widely used Sb substitution on the Sn site. The influence of the Ta content on the thermoelectric and transport properties of (Zr0.3Hf0.7-xTax)NiSn (x = 0, 0.01, 0.05) is investigated by means of Seebeck coefficient, electrical resistivity, thermal conductivity, and Hall coefficient measurements. The results are analyzed in context of the single parabolic band model. Ta substitution increases the charge carrier concentration and suppresses the influence of impurity band, which is present in the pristine (Zr0.3Hf0.7)NiSn. Moreover, Ta substitution decouples and simultaneously increases the density-of-states effective mass (m*) and the charge carrier mobility (μ), leading to a larger weighted mobility μ·(m*)3/2. The lattice thermal conductivity is slightly suppressed due to increased point defect scattering. A... |
| Databáze: | OpenAIRE |
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