Mg₃(Sb,Bi)₂-based materials have attracted increasing attention owing to the comparable thermoelectric performance to state-of-the-art Bi₂Te₃-based alloys. However, their intrinsic low carrier mobility issue severely restricts their room-temperature performance. Herein, by carefully manipulating the magnetic diffuse scattering effect through Co secondary impurity incorporation, we discovered that carrier mobility can be unusually increased and lattice thermal conductivity is significantly suppressed. Negative magnetoresistance with square field dependence (H²) revealed the beneficial contribution of the magnetism-induced diffuse scattering effect to the enhancement of carrier mobility by 46%. The increased full width at half maximum of the Raman spectrum corroborates the decrease in lattice thermal conductivity. As a result, a maximum zT of 0.94 at 300 K and an average zT of 1.17 at 300–400 K were achieved in magnetic Mg₃(Sb,Bi)₂-based alloys. This work demonstrates a robust magnetism-induced diffuse scattering effect in improving the room-temperature thermoelectric performance.

中文翻译：

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磁致漫散射效应触发优异的热电性能


Mg ₃ (Sb,Bi) ₂ 基材料由于与最先进的 Bi ₂ Te 具有可比的热电性能而引起了越来越多的关注 ₃ 基合金。然而，它们固有的低载流子迁移率问题严重限制了它们的室温性能。在此，通过Co二次杂质掺入仔细操纵磁漫散射效应，我们发现载流子迁移率可以异常增加，并且晶格热导率可以得到显着抑制。具有平方场依赖性的负磁阻（H ² ）揭示了磁致漫散射效应对载流子迁移率提高46%的有益贡献。拉曼光谱半峰全宽的增加证实了晶格热导率的降低。结果，磁性 Mg ₃ (Sb,Bi) ₂ 基合金在 300 K 时的最大 zT 为 0.94，在 300–400 K 时的平均 zT 为 1.17 。这项工作展示了在改善室温热电性能方面强大的磁致漫散射效应。