ABSTRACT Fe2VAl is well known as a promising candidate for thermoelectric applications due to its sharp pseudogap at the Fermi level. However, its energy conversion performance is compromised by its high thermal conductivity. Our previous studies revealed that antisite defects like AlV, AlFe, and VAl are the most likely imperfections in Fe2VAl [1]. It is thus important to understand the electron and phonon transport properties in these defective crystals to estimate their thermoelectric efficiency. Here we analyze the electronic transport properties of Fe2VAl solid solutions based on Boltzmann transport theory within the constant relaxation time approximation. We then calculate the lattice thermal conductivity of Fe2VAl containing AlV antisite defects by solving the linearized Boltzmann transport equation based on an ab initio model for defects. We find a significant increase of around an order of magnitude in ZT at 300 K compared to the stoichiometric compound.

中文翻译：

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反位缺陷对Fe2VAl热电性能的影响

摘要 Fe2VAl 因其在费米能级的尖锐赝隙而被公认为热电应用的有前途的候选材料。然而，其能量转换性能因其高导热性而受到损害。我们之前的研究表明，像 AlV、AlFe 和 VAl 等反位缺陷是 Fe2VAl 中最有可能的缺陷 [1]。因此，了解这些有缺陷的晶体中的电子和声子传输特性以估计它们的热电效率非常重要。在这里，我们基于常数弛豫时间近似内的玻尔兹曼传输理论分析了 Fe2VAl 固溶体的电子传输特性。然后，我们通过求解基于缺陷的 ab initio 模型的线性化 Boltzmann 传输方程来计算含有 AlV 反位缺陷的 Fe2VAl 的晶格热导率。