Enhanced Thermoelectric Figure of Merit of p-Type Half-Heuslers

被引：354

作者：

Yan, Xiao ^{[2
]}

Joshi, Giri ^{[2
]}

Liu, Weishu ^{[2
]}

Lan, Yucheng ^{[2
]}

Wang, Hui ^{[2
]}

Lee, Sangyeop ^{[1
]}

Simonson, J. W. ^{[3
]}

Poon, S. J. ^{[3
]}

Tritt, T. M. ^{[4
]}

Chen, Gang ^{[1
]}

Ren, Z. F. ^{[2
]}

机构：

[1] MIT, Dept Mech Engn, Cambridge, MA 02139 USA

[2] Boston Coll, Dept Phys, Chestnut Hill, MA 02467 USA

[3] Univ Virginia, Dept Phys, Charlottesville, VA 22904 USA

[4] Clemson Univ, Dept Phys & Astron, Clemson, SC 29634 USA

来源：

NANO LETTERS | 2011年 / 11卷 / 02期

关键词：

Thermoelectrics; half-Heusler; nanocomposite; ball milling; hot pressing; OF-MERIT;

D O I：

10.1021/nl104138t

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Half-Heuslers would be important thermoelectric materials due to their high temperature stability and abundance if their dimensionless thermoelectric figure of merit (ZT) could be made high enough. The highest peak ZT of a p-type half-Heusler has been so far reported about 0.5 due to the high thermal conductivity. Through a nanocomposite approach using ball milling and hot pressing, we have achieved a peak ZT of 0.8 at 700 degrees C, which is about 60% higher than the best reported 0.5 and might be good enough for consideration for waste heat recovery in car exhaust systems. The improvement comes from a simultaneous increase in Seebeck coefficient and a significant decrease in thermal conductivity due to nanostructures. The samples were made by first forming alloyed ingots using arc melting and then creating nanopowders by ball milling the ingots and finally obtaining dense bulk by hot pressing. Further improvement in ZT is expected when average grain sizes are made smaller than 100 nm.

引用

页码：556 / 560

页数：5