In this article, we investigate the lattice thermal conductivity in the thermoelectric Fe₂VAl Heusler alloy by implementing a Green’s function approach to describe phonon-defect scattering mechanisms in the pristine and substituted compounds. Former calculations for pristine Fe₂VAl largely overestimated the lattice thermal conductivity compared to the experimental value (28 W m⁻¹ K⁻¹). By considering a realistic concentration ( ~ 5%) of combined Al_V and V_Al antisite defects as an extra phonon scattering mechanism, calculated and experimental values could be reconciled. The same theoretical approach was applied to Ta- and Ta + Sn-substituted Fe₂VAl. In agreement with experiments it shows that the dual Ta + Sn-substitution is more efficient in decreasing the lattice thermal conductivity of Fe₂VAl than the single Ta-substitution. A strong decrease of 70% is theoretically obtained in Fe₂V_0.96Ta_0.04Al_0.96Sn_0.04 which could thus lead to better global thermoelectric performances.

在本文中，我们通过实施格林函数方法来描述原始和取代化合物中的声子缺陷散射机制，研究热电 Fe ₂ VAl Heusler 合金的晶格热导率。与实验值（28 W m ^-1 K ^-1）相比，原始Fe ₂ VAl 的先前计算在很大程度上高估了晶格热导率。通过考虑组合的 Al _V和 V _Al反位缺陷的实际浓度（~5%）作为额外的声子散射机制，计算值和实验值可以协调。相同的理论方法应用于 Ta 和 Ta + Sn 取代的 Fe ₂瓦尔。与实验一致，它表明双Ta + Sn 取代在降低Fe ₂ VAl的晶格热导率方面比单一Ta 取代更有效。在 Fe ₂ V _0.96 Ta _0.04 Al _0.96 Sn _{0.04 中}理论上获得了 70% 的强烈降低，这可能因此导致更好的整体热电性能。