Thermoelectric performance of a metastable thin-film Heusler alloy
Thermoelectric performance of a metastable thin-film Heusler alloy
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DOI：
10.1038/s41586-019-1751-9
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发表时间：
2019-12-05
期刊：
影响因子：
64.8
通讯作者：
Bauer, E.
中科院分区：
文献类型：
--
作者：
Hinterleitner, B.;Knapp, I.;Bauer, E.
热电材料将热梯度转化为电。该过程的效率依赖于三个材料相关参数：塞贝克系数、电阻率和热导率，总结在热电优值中。大的品质因数对于诸如热电发电机的潜在应用是有益的。本文报道了用磁控溅射法制备的Fe_2V_0.8W_0.2Al基Heusler合金薄膜的热学和电学性质。密度泛函理论计算表明，薄膜是亚稳态，和测量oft他的功率因数的比的塞贝克系数平方除以电介电性，建议这些薄膜的高内在品质因数。这可能是由于费米能级处的大的微分态密度和接近费米能级的类外尔电子色散引起的，这表明由于电子能带中的线性交叉而导致的电荷载流子的高迁移率。
Thermoelectric materials transform a thermal gradient into electricity. The efficiency of this process relies on three material-dependent parameters:the Seebeck coefficient, the electrical resistivity and the thermal conductivity, summarized in the thermoelectric figure of merit. A large figure of merit is beneficial for potential applications such as thermoelectric generators. Here we report the thermal and electronic properties of thin-film Heusler alloys based on Fe2V0.8W0.2Al prepared by magnetron sputtering. Density functional theory calculations suggest that the thin films are metastable states, and measurements oft he power factor-the ratio of the Seebeck coefficient squared divided by the electrical resistivity-suggest a high intrinsic figure of merit for these thin films. This may arise from a large differential density of states at the Fermi level and a Weyl-like electron dispersion close to the Fermi level, which indicates a high mobility of charge carriers owing to linear crossing in the electronic bands.