Unexpected High-Temperature Stability of β-Zn4Sb3 Opens the Door to Enhanced Thermoelectric Performance

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• 作者：Jianping Lin ; Xudong Li ; Guanjun Qiao ; Zhao Wang ; Jesús Carrete ; Yang Ren ; Lingzhi Ma ; Youjian Fei ; Baifeng Yang ; Lei Lei ; Ju Li
• 刊名：Journal of the American Chemical Society
• 出版年：2014
• 出版时间：January 29, 2014
• 年：2014
• 卷：136
• 期：4
• 页码：1497-1504
• 全文大小：614K
• ISSN：1520-5126

文摘

尾-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 尾-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; 尾-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.