Doping Effects on Thermoelectric Properties of the Pseudogap Fe 2 VAl System
Doping Effects on Thermoelectric Properties of the Pseudogap Fe 2 VAl System
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DOI：
10.2320/jinstmet1952.66.7_767
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发表时间：
2002
影响因子：
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通讯作者：
Hitoshi Matsuura;Y. Nishino;U. Mizutani;S. Asano
中科院分区：
文献类型：
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作者：
Hitoshi Matsuura;Y. Nishino;U. Mizutani;S. Asano
我们报告了 y=00.25 的 Fe2(V1-yTiy)Al 和 z=00.20 的 Fe2(V1-zMoz)Al 的电阻率、塞贝克系数和霍尔系数的温度依赖性。虽然Heusler型Fe2VAl（y=z=0）表现出类似半导体的电阻率行为，但Ti或Mo轻微替代V会导致低温电阻率急剧下降，塞贝克系数S大幅提高：S的符号对于Ti替代为正，而对于Mo替代为负。塞贝克系数的显着增强与霍尔系数的变化合理一致，并且可以根据Fe2VAl的电子结构来解释，其中当用Ti或Mo替代V时，费米能级预计会从赝能隙中心稍微移动。特别是，Mo替代导致室温下4×10-3 W/mK2的大功率因数，这与传统热电材料的功率因数相当。
We report on the temperature dependence of electrical resistivity, Seebeck coefficient and Hall coefficient for Fe2(V1-yTiy)Al with y=00.25 and Fe2(V1-zMoz)Al with z=00.20. While the Heuslertype Fe2VAl ( y=z=0) exhibits a semiconductorlike resistivity behavior, a slight substitution of Ti or Mo for V causes a sharp decrease in the lowtemperature resistivity and a large enhancement in the Seebeck coefficient S: a sign of S is positive for the Ti substitution but negative for the Mo substitution. Substantial enhancements for the Seebeck coefficient are in reasonable accord with changes in the Hall coefficient and can be explained on the basis of the electronic structure of Fe2VAl, where the Fermi level is expected to shift slightly from the center of the pseudogap upon the substitution of Ti or Mo for V. In particular, the Mo substitution leads to a large power factor of 4×10-3 W/mK2 at room temperature, which is comparable to that of conventional thermoelectric materials.