Effect of Ti Substitution on Thermoelectric Properties of W-Doped Heusler Fe2VAl Alloy
| Autor: | Atsushi Yamamoto, H. Takazawa, Tsunehiro Takeuchi, Masashi Mikami, Kimihiro Ozaki, Yuichi Terazawa |
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| Rok vydání: | 2013 |
| Předmět: |
Materials science
Alloy Doping Metallurgy technology industry and agriculture Analytical chemistry engineering.material Condensed Matter Physics Thermoelectric materials Electronic Optical and Magnetic Materials Thermal conductivity Electrical resistivity and conductivity Seebeck coefficient Thermoelectric effect Materials Chemistry engineering Electrical and Electronic Engineering Valence electron |
| Zdroj: | Journal of Electronic Materials. 42:1801-1806 |
| ISSN: | 1543-186X 0361-5235 |
| Popis: | Effects of element substitutions on thermoelectric properties of Heusler Fe2VAl alloys were evaluated. By W substitution at the V site, the thermal conductivity is reduced effectively because of the enhancement of phonon scattering resulting from the introduction of W atoms, which have much greater atomic mass and volume than the constituent elements of Fe2VAl alloy. W substitution is also effective to obtain a large negative Seebeck coefficient and high electrical conductivity through an electron injection effect. To change the conduction type from n-type to p-type, additional Ti substitution at the V site, which reduces the valence electron density, was examined. A positive Seebeck coefficient as high as that of conventional p-type Fe2VAl alloy was obtained using a sufficient amount of Ti substitution. Electrical resistivity was reduced by the hole doping effect of the Ti substitution while maintaining low thermal conductivity. Compared with the conventional solo-Ti-substituted p-type Fe2VAl alloy, the ZT value was improved, reaching 0.13 at 450 K. |
| Databáze: | OpenAIRE |
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