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Praseodymium Telluride: A High-Temperature, High-ZT Thermoelectric Material
Joule ( IF 38.6 ) Pub Date : 2018-02-19 , DOI: 10.1016/j.joule.2018.01.013
Dean Cheikh , Brea E. Hogan , Trinh Vo , Paul Von Allmen , Kathleen Lee , David M. Smiadak , Alexandra Zevalkink , Bruce S. Dunn , Jean-Pierre Fleurial , Sabah K. Bux

Refractory rare-earth tellurides with the Th3P4 structure type have attracted considerable interest as high-performance thermoelectric materials since the 1980s due to their high dimensionless figure of merit (ZT). Extensive work has been conducted on La3−xTe4 with peak ZT values greater than 1.1 at 1,273 K. The high ZT of La3-xTe4 is in part due to a large peak in the density of states near the Fermi level from the La 5d states. Here, we revisit Pr3−xTe4, for which our electronic structure calculations predict a favorable modification of the density of states by the introduction of praseodymium's 4f electrons. This was experimentally verified by preparing Pr3−xTe4 samples with varying Pr vacancy concentrations using a mechanochemical synthesis approach. The thermoelectric properties were measured and a ZT of 1.7 at 1,200 K was achieved with Pr2.74Te4. The 50% improvement in peak ZT compared with La3−xTe4 resulted from an increased effective mass, improved Seebeck coefficient, and lower thermal conductivity.



中文翻译:

碲化:高温,高ZT热电材料

自1980年代以来,具有Th 3 P 4结构类型的难熔稀土碲化物因其无量纲的高品质因数(ZT)而作为高性能热电材料引起了人们的极大兴趣。大量工作已有关La已经进行3- X4与峰ZT在1273 K的高值大于1.1的ZT的La 3- X4是部分地由于在状态的费米能级附近的密度大的峰值来自La 5d州。在这里,我们重新审视Pr 3− x Te 4,我们的电子结构计算通过predict 4f电子的引入预测了态密度的有利变化。通过使用机械化学合成方法制备具有不同Pr空位浓度的Pr 3- x Te 4样品,通过实验验证了这一点。测量了热电性能,并用Pr 2.74 Te 4在1200 K下实现了1.7的ZT。与La 3- x Te 4相比,ZT峰值提高了50%,这是由于有效质量增加,塞贝克系数提高和热导率降低所致。

更新日期:2018-02-19
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