Stronger phonon scattering by larger differences in atomic mass and size in p-type half-Heuslers Hf1−xTixCoSb0.8Sn0.2

High lattice thermal conductivity has been the bottleneck for further improvement of the thermoelectric figure-of-merit (ZT) of half-Heuslers (HHs) Hf1−xZrxCoSb0.8Sn0.2. 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., Hf1−xTixCoSb0.8Sn0.2, 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 Hf1−xTixCoSb0.8Sn0.2 (x = 0.1, 0.2, 0.3, and 0.5) system was achieved using Hf0.8Ti0.2CoSb0.8Sn0.2, which makes this material useful in power generation applications.

[1]  Chude Feng,et al.  Disorder scattering effect on the high-temperature lattice thermal conductivity of TiCoSb-based half-Heusler compounds , 2005 .

[2]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[3]  L. Bell.  Cooling, Heating, Generating Power, and Recovering Waste Heat with Thermoelectric Systems , 2008, Science.

[4]  S. Yamanaka,et al.  Thermoelectric properties of Sn-doped TiCoSb half-Heusler compounds , 2006 .

[5]  Junichiro Shiomi,et al.  Thermal conductivity of half-Heusler compounds from first-principles calculations , 2011 .

[6]  Qian Zhang,et al.  Thermoelectric Property Studies on Cu‐Doped n‐type CuxBi2Te2.7Se0.3 Nanocomposites , 2011 .

[7]  Hohyun Lee,et al.  Enhanced thermoelectric figure-of-merit in nanostructured p-type silicon germanium bulk alloys. , 2008, Nano letters.

[8]  P. Poudeu,et al.  Effects of Ir Substitution and Processing Conditions on Thermoelectric Performance of p-Type Zr0.5Hf0.5Co1−xIrxSb0.99Sn0.01 Half-Heusler Alloys , 2011 .

[9]  张清杰,et al.  Fast preparation and thermal transport property of TiCoSb-based half-Heusler compounds , 2007 .

[10]  Lidong Chen,et al.  Effects of Ge doping on the thermoelectric properties of TiCoSb-based p-type half-Heusler compounds , 2009 .

[11]  G. J. Snyder,et al.  Enhancement of Thermoelectric Efficiency in PbTe by Distortion of the Electronic Density of States , 2008, Science.

[12]  Ping Jen Lee,et al.  High-temperature thermoelectric properties of Tix(ZrHf)0.99−xV0.01Ni0.9Pd0.1Sn0.99Sb0.01 half-Heusler alloys , 2010 .

[13]  Lidong Chen,et al.  Thermoelectric properties of p-type Fe-doped TiCoSb half-Heusler compounds , 2007 .

[14]  P. Poudeu,et al.  Effects of Rh on the thermoelectric performance of the p-type Zr0.5Hf0.5Co1-xRhxSb0.99Sn0.01 half-Heusler alloys , 2010 .

[15]  Gang Chen,et al.  Enhanced thermoelectric figure of merit of p-type half-Heuslers. , 2011, Nano letters.

[16]  Andrew G. Glen,et al.  APPL , 2001 .

[17]  R. Rosenfeld.  Nature , 2009, Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery.

[18]  R. K. Williams,et al.  Filled Skutterudite Antimonides: A New Class of Thermoelectric Materials , 1996, Science.

[19]  Ji-Hui Yang,et al.  Automotive Applications of Thermoelectric Materials , 2009 .

[20]  Heng Wang,et al.  Convergence of electronic bands for high performance bulk thermoelectrics , 2011, Nature.

[21]  S. Poon,et al.  Thermoelectric properties of p-type half-Heusler alloys Zr1−xTixCoSnySb1−y (0.0 , 2008 .

[22]  D. Mills.  Advances in solar thermal electricity technology , 2004 .

[23]  Gang Chen,et al.  High-performance flat-panel solar thermoelectric generators with high thermal concentration. , 2011, Nature materials.

[24]  S. Poon,et al.  (Zr,Hf)Co(Sb,Sn) half-Heusler phases as high-temperature (>700°C) p-type thermoelectric materials , 2008 .

[25]  S. Poon,et al.  Thermoelectric properties of semimetallic (Zr, Hf)CoSb half-Heusler phases , 2000 .

[26]  Shinsuke Yamanaka,et al.  High-Thermoelectric Figure of Merit Realized in p-Type Half-Heusler Compounds: ZrCoSnxSb1-x , 2007 .

[27]  G. A. Slack,et al.  Effect of Isotopes on Low-Temperature Thermal Conductivity , 1957 .

[28]  Terry M. Tritt,et al.  Recent trends in thermoelectric materials research , 2001 .

[29]  Y. Kimura,et al.  Thermoelectric Properties of Directionally Solidified Half-Heusler (M0.5a,M0.5b)NiSn (Ma, Mb = Hf, Zr, Ti) Alloys , 2009 .

[30]  Maria Telkes,et al.  Solar Thermoelectric Generators , 1954 .

[31]  G. Meisner,et al.  Strain field fluctuation effects on lattice thermal conductivity of ZrNiSn-based thermoelectric compounds , 2004 .

[32]  Hohyun Lee,et al.  Enhanced thermoelectric figure of merit in nanostructured n-type silicon germanium bulk alloy , 2008 .