State Key Laboratory for Mechanical Behavior of Materials and ‡Frontier Institute of Science and Technology, Xi'an Jiaotong University , Xi'an, 710049, P. R. China.
J Am Chem Soc. 2014 Jan 29;136(4):1497-504. doi: 10.1021/ja410605f. Epub 2014 Jan 13.
β-Zn4Sb3 has one of the highest ZT reported for binary compounds, but its practical applications have been hindered by a reported poor stability. Here we report the fabrication of nearly dense single-phase β-Zn4Sb3 and a study of its thermoelectric transport coefficients across a wide temperature range. Around 425 K we find an abrupt decrease of its thermal conductivity. Past this point, Zn atoms can migrate from crystalline sites to interstitial positions; β-Zn4Sb3 becomes metastable and gradually decomposes into Zn(hcp) and ZnSb. However, above 565 K it recovers its stability; in fact, the damage caused by decomposition can be repaired completely. This is key to its excellent thermoelectric performance at high temperature: the maximum ZT reaches 1.4. Molecular dynamics simulations are used to shed light on the microscopic behavior of the material.
β-Zn4Sb3 是二元化合物中具有最高 ZT 值之一的材料，但由于其报道的较差的稳定性，其实际应用受到了阻碍。在这里，我们报告了近致密单相 β-Zn4Sb3 的制备，并在很宽的温度范围内研究了其热电输运系数。在大约 425 K 时，我们发现其热导率急剧下降。超过这个温度后，Zn 原子可以从晶格格点迁移到间隙位置；β-Zn4Sb3 变得亚稳，并逐渐分解为 Zn(hcp)和 ZnSb。然而，在 565 K 以上，它又恢复了稳定性；实际上，分解造成的损坏可以完全修复。这是其在高温下具有优异热电性能的关键：最大 ZT 值达到 1.4。分子动力学模拟被用来揭示材料的微观行为。
