Abstract In this work we improved the thermoelectric figure of merit ZT in a LaxCoFe3Sb12 (x = 0.80, 0.85, 0.90) skutterudite system by applying a conductivity ratio (electrical to thermal) control method based on the phonon-glass electron-crystal (PGEC) approach. Polycrystalline bulks of LaxCoFe3Sb12 were prepared by melt-spinning and subsequent spark plasma sintering. Based on the thermoelectric transport properties and microstructural analysis, we found that large amount of La-filler (x ≥ 0.9) in the LaxCoFe3Sb12 system is necessary to increase the conductivity ratio required to improve the thermoelectric properties in the LaxCoFe3Sb12 system. Resultantly, the maximum ZT value of 0.87 was obtained at 723 K in the heavily filled La0.9CoFe3Sb12. We discuss our results on the basis of the filling level dependence of the rattling effect and on the formation of the skutterudite single phase. We also confirm that a large amount of La-filling level is necessary to meet the electrical neutrality condition of the p-type LaxCoFe3Sb12 skutterudite system.

中文翻译：

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使用熔体纺丝工艺控制 p 型 La x Fe 3 CoSb 12 热电材料的电热导率比

摘要 在这项工作中，我们通过应用基于声子玻璃电子晶体 (PGEC) 的电导率比（电热）控制方法改进了 LaxCoFe3Sb12 (x = 0.80, 0.85, 0.90) 方钴矿系统中的热电品质因数 ZT方法。LaxCoFe3Sb12 的多晶块体通过熔融纺丝和随后的放电等离子烧结制备。基于热电传输特性和微观结构分析，我们发现在 LaxCoFe3Sb12 体系中需要大量的 La 填料（x ≥ 0.9）来增加提高 LaxCoFe3Sb12 体系热电性能所需的电导率比。结果，在高度填充的 La0.9CoFe3Sb12 中，在 723 K 时获得了 0.87 的最大 ZT 值。我们根据颤动效应的填充水平依赖性和方钴矿单相的形成来讨论我们的结果。我们还确认需要大量的 La 填充水平才能满足 p 型 LaxCoFe3Sb12 方钴矿系统的电中性条件。