Theory of huge thermoelectric effect based on a magnon drag mechanism: Application to thin-film Heusler alloy
Theory of huge thermoelectric effect based on a magnon drag mechanism: Application to thin-film Heusler alloy
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DOI：
10.1103/physrevb.104.214421
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发表时间：
2021-12-15
影响因子：
3.7
通讯作者：
Bauer, Ernst
中科院分区：
文献类型：
--
作者：
Matsuura, Hiroyasu;Ogata, Masao;Bauer, Ernst
为了理解在薄膜Heusler合金Fe2V0.8W0.2Al中观察到的出乎意料的高热电性能，我们研究了由钨基杂质带产生的磁振子拖曳效应，作为这种增强的可能来源，类似于在FeSb 2中观察到的声子拖曳。假设薄膜Heusler合金有一个导带集成的杂质带，起源于钨替代，我们推导出的电导率L11的自洽的t矩阵近似的基础上，由于磁振子拖曳的线性响应理论的基础上的热电电导率L12和估计的温度依赖的电阻率，塞贝克系数，和功率因数。最后，我们将理论结果与薄膜Heusler合金的实验结果进行了比较，表明异常热电性能的起源可能是由于与钨基杂质带相关的磁振子阻力。
To understand the unexpectedly high thermoelectric performance observed in the thin-film Heusler alloy Fe2V0.8W0.2Al, we study the magnon drag effect, generated by the tungsten-based impurity band, as a possible source of this enhancement, in analogy to the phonon drag observed in FeSb2. Assuming that the thin-film Heusler alloy has a conduction band integrating with the impurity band, originated by the tungsten substitution, we derive the electrical conductivity L11 based on the self-consistent t-matrix approximation and the thermoelectric conductivity L12 due to magnon drag based on the linear response theory and estimate the temperature-dependent electrical resistivity, Seebeck coefficient, and power factor. Finally, we compare the theoretical results with the experimental results of the thin-film Heusler alloy to show that the origin of the exceptional thermoelectric properties is likely due to the magnon drag related to the tungsten-based impurity band.