Abstract Although filled skutterudites have a high figure of merit, ZT, it is still an aim to further improve their thermoelectric behavior. One successful route is to homogeneously disperse nanoparticles into the skutterudite matrix and thereby to reduce the lattice thermal conductivity without disturbing the electrical conductivity and the Seebeck coefficient. In this work Ta0.8Zr0.2B was dispersed into n-type (Mm,Sm)yCo4Sb12 powder by ball-milling or high energy ball-milling prior to hot-pressing. Structural and physical properties, covering also the low temperature range, were studied and compared with the recently investigated impact of nano Ta0.8Zr0.2B on p-type skutterudites. ZT was enhanced by 16%. As for thermoelectric applications good mechanical properties are important, we investigated the influence of Ta0.8Zr0.2B nanoparticles, added to (Mm,Sm)yCo4Sb12, on the hardness, elastic moduli and fracture toughness and found an enhancement of all three mechanical properties. It is well known that p-type skutterudites generally have a higher thermal expansion coefficient than their n-type counterpart. We show that dispersed borides in both n-type (Mm,Sm)yCo4Sb12 and p-type DD0.7Fe3CoSb12 can level out this discrepancy.

中文翻译：

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纳米结构作为调节高 ZT 方钴矿热膨胀的工具

摘要 尽管填充方钴矿具有很高的品质因数 ZT，但仍需进一步改善其热电行为。一种成功的途径是将纳米粒子均匀地分散到方钴矿基体中，从而在不干扰电导率和塞贝克系数的情况下降低晶格热导率。在这项工作中，在热压之前，通过球磨或高能球磨将 Ta0.8Zr0.2B 分散到 n 型 (Mm,Sm)yCo4Sb12 粉末中。研究了结构和物理特性，包括低温范围，并与最近研究的纳米 Ta0.8Zr0.2B 对 p 型方钴矿的影响进行了比较。ZT 增强了 16%。对于热电应用，良好的机械性能很重要，我们研究了 Ta0.8Zr0.2B 纳米颗粒的影响，添加到 (Mm,Sm)yCo4Sb12 中后，硬度、弹性模量和断裂韧性均有所提高，并发现所有三种机械性能都有所提高。众所周知，p 型方钴矿通常比它们的 n 型方钴矿具有更高的热膨胀系数。我们表明，n 型 (Mm,Sm)yCo4Sb12 和 p 型 DD0.7Fe3CoSb12 中的分散硼化物可以消除这种差异。