Stronger phonon scattering by larger differences in atomic mass and size in p-type half-Heuslers Hf[subscript 1−x]Ti[subscript x]CoSb[subscript 0.8]Sn[subscript 0.2]
Author(s)Yan, Xiao; Liu, Weishu; Wang, Hui; Chen, Shuo; Shiomi, Junichiro; Esfarjani, Keivan; Wang, Hengzhi; Wang, Dezhi; Chen, Gang; Ren, Zhifeng; ... Show more Show less
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High lattice thermal conductivity has been the bottleneck for further improvement of the thermoelectric figure-of-merit (ZT) of half-Heuslers (HHs) Hf[subscript 1−x]Zr[subscript x]CoSb[subscript 0.8]Sn[subscript 0.2]. Theoretically, the lattice thermal conductivity can be reduced by exploring larger differences in the atomic mass and size in the crystal structure, leading to higher ZT. In this paper, we experimentally demonstrated that a lower thermal conductivity in p-type half-Heuslers can be achieved when Ti is used to replace Zr, i.e., Hf[subscript 1−x]Ti[subscript x]CoSb[subscript 0.8]Sn[subscript 0.2], due to larger differences in the atomic mass and size between Hf and Ti compared with Hf and Zr. The highest ZT peak, ~1.0 at 800 °C, in the Hf[subscript 1−x]Ti[subscript x]CoSb[subscript 0.8]Sn[subscript 0.2] (x = 0.1, 0.2, 0.3, and 0.5) system was achieved using Hf[subscript 0.8]Ti[subscript 0.2]CoSb[subscript 0.8]Sn[subscript 0.2], which makes this material useful in power generation applications.
DepartmentMassachusetts Institute of Technology. Department of Mechanical Engineering
Energy & Environmental Science
Royal Society of Chemistry
Yan, Xiao, Weishu Liu, Hui Wang, Shuo Chen, Junichiro Shiomi, Keivan Esfarjani, Hengzhi Wang, Dezhi Wang, Gang Chen, and Zhifeng Ren. “Stronger Phonon Scattering by Larger Differences in Atomic Mass and Size in p-Type Half-Heuslers Hf1−xTixCoSb0.8Sn0.2.” Energy & Environmental Science 5, no. 6 (2012): 7543.
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