Article

Thermoelectric Property Study of Nanostructured p‐Type Half‐Heuslers (Hf, Zr, Ti)CoSb<sub>0.8</sub>Sn<sub>0.2</sub>

Xiao YanDepartment of Physics and TcSUH, University of Houston, Houston, Texas 77204, USAWeishu LiuDepartment of Physics and TcSUH, University of Houston, Houston, Texas 77204, USAShuo ChenDepartment of Physics and TcSUH, University of Houston, Houston, Texas 77204, USAHui WangDepartment of Physics and TcSUH, University of Houston, Houston, Texas 77204, USAQian ZhangDepartment of Physics and TcSUH, University of Houston, Houston, Texas 77204, USAGang ChenDepartment of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USAZhifeng RenDepartment of Physics and TcSUH, University of Houston, Houston, Texas 77204, USA

2013en

ABI

Abstract

Abstract Based on the best peak theromoelectric figure‐of‐merit value ( ZT ) of ca. 0.8 in Hf 0.5 Zr 0.5 CoSb 0.8 Sn 0.2 and ca. 1 in Hf 0.8 Ti 0.2 CoSb 0.8 Sn 0.2 , the effect of Ti on thermoelectric properties is studied in (Hf, Zr, Ti)CoSb 0.8 Sn 0.2 , with the aim of further improving the ZT and reducing the usage of Hf. By either partial replacement of Hf and Zr with Ti in Hf 0.5 Zr 0.5 CoSb 0.8 Sn 0.2 or partial replacement of Hf and Ti with Zr in Hf 0.8 Ti 0.2 CoSb 0.8 Sn 0.2 , a peak ZT of ≥1 is achieved at 800°C in Hf 0.44 Zr 0.44 Ti 0.12 CoSb 0.8 Sn 0.2 . This composition has two advantages over the previous two best compositions: higher ZT than Hf 0.5 Zr 0.5 CoSb 0.8 Sn 0.2 and less Hf than in Hf 0.8 Ti 0.2 CoSb 0.8 Sn 0.2 . A higher ZT with less Hf is very much desired since Hf is much more expensive than other constituent elements. The ZT improvement is the result of thermal conductivity reduction due to phonon scattering by both alloy and the nanostructure effect.

Identifiers

DOI: 10.1002/aenm.201200973

Citations and references

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