Journal of Materials Science

, Volume 53, Issue 12, pp 9117–9130 | Cite as

Effect of annealing on microstructure and thermoelectric properties of hot-extruded Bi–Sb–Te bulk materials

  • Zhi-Lei Wang
  • Takehiro Araki
  • Tetsuhiko Onda
  • Zhong-Chun Chen
Electronic materials


The effect of annealing on the microstructure, thermoelectric properties and hardness of the hot-extruded Bi–Sb–Te materials has been investigated systematically to optimize their thermoelectric and mechanical properties. The mechanically alloyed powder was consolidated by hot extrusion at either 340 or 400 °C, followed by annealing in a temperature range of 260–400 °C. The microstructure of the annealed samples contained submicron grains with preferred (001) texture. As annealing temperature increased, the small-angle grain boundaries (SAGBs) increased because the increased amount of Te-rich and Sb-rich phases inhibits the movements of dislocations and SAGBs. The submicron microstructure led to a low thermal conductivity, for example, ~ 0.9 W/mK after annealing at TA ≥ 380 °C. The Seebeck coefficient highly depended on carrier mobility in addition to carrier concentration. For the extruded samples prepared at a lower extrusion temperature of 340 °C, the mobility increased significantly after annealing, resulting in great enhancements in the Seebeck coefficient and electrical conductivity. A peak ZT value of 0.94 and high hardness were simultaneously obtained under the conditions of hot extrusion at 340 °C and annealing at 380 °C. It seems that the combination of low-temperature extrusion and high-temperature annealing is an effective route to prepare high-performance Bi2Te3-based materials.



The authors would like to thank Prof. Takahiro Akao of National Institute of Technology and Profs. Shigekazu Morito and Hiroyuki Kitagawa of Shimane University for their experimental supports and fruitful discussion. This work was supported in part by the Amada Foundation (AF-2013007) and Nippon Sheet Glass Foundation for Materials Science and Engineering.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.


  1. 1.
    Disalvo FJ (1999) Thermoelectric cooling and power generation. Science 285:703–706CrossRefGoogle Scholar
  2. 2.
    Sales BC (2002) Smaller is cooler. Science 295:1248–1249CrossRefGoogle Scholar
  3. 3.
    Biswas K, He J, Blum ID, Wu CI, Hogan TP, Seidman DN, Dravid VP, Kanatzidiset MG (2012) High-performance bulk thermoelectrics with all-scale hierarchical architectures. Nature 489:414–418CrossRefGoogle Scholar
  4. 4.
    Bachmann M, Czerner M, Heiliger C (2012) Ineffectiveness of energy filtering at grain boundaries for thermoelectric materials. Phys Rev B 86:115320CrossRefGoogle Scholar
  5. 5.
    Amatya R, Ram RJ (2012) Trend for thermoelectric materials and their earth abundance. J Electron Mater 41:1011–1019CrossRefGoogle Scholar
  6. 6.
    Minnich AJ, Dresselhaus MS, Ren ZF, Chen G (2009) Bulk nanostructured thermoelectric materials: current research and future prospects. Energy Environ Sci 2:466–479CrossRefGoogle Scholar
  7. 7.
    Snyder GJ, Toberer ES (2008) Complex thermoelectric materials. Nat Mater 7:105–114CrossRefGoogle Scholar
  8. 8.
    Im JT, Hartwig KT, Sharp J (2004) Microstructural refinement of cast p-type Bi2Te3–Sb2Te3 by equal channel angular extrusion. Acta Mater 52:49–55CrossRefGoogle Scholar
  9. 9.
    Weise JR, Muller L (1960) Lattice constants of Bi2Te3–Bi2Se3 solid solution alloys. J Phys Chem Solids 15:13CrossRefGoogle Scholar
  10. 10.
    Schulz LG (1949) A direct method of determining preferred orientation of a flat reflection sample using a geiger counter X-ray spectrometer. J Appl Phys 20:1030–1033CrossRefGoogle Scholar
  11. 11.
    Taylor PJ, Maddux JR, Jesser WA, Rosi FD (1999) Room-temperature anisotropic, thermoelectric, and electrical properties of n-type (Bi2Te3)90(Sb2Te3)5(Sb2Se3)5 and compensated p-type (Sb2Te3)72(Bi2Te3)25(Sb2Se3)3 semiconductor alloys. J Appl Phys 85:7807–7813CrossRefGoogle Scholar
  12. 12.
    Yim WM, Rosi FD (1972) Compound tellurides and their alloys for peltier cooling—a review. Solid State Electron 15:1121CrossRefGoogle Scholar
  13. 13.
    Yang JY, Aizawa T, Yamamoto A, Ohtab T (2000) Thermoelectric properties of n-type (Bi2Se3)x(Bi2Te3)1−x prepared by bulk mechanical alloying and hot pressing. J Alloys Compd 312:326–330CrossRefGoogle Scholar
  14. 14.
    Boulanger C (2010) Thermoelectric material electroplating: a historical review. J Electron Mater 39:1818–1827CrossRefGoogle Scholar
  15. 15.
    Jiang J, Chen LD, Bai SQ, Yao Q (2005) Thermoelectric performance of p-type Bi–Sb–Te materials prepared by spark plasma sintering. J Alloys Compd 390:208–211CrossRefGoogle Scholar
  16. 16.
    Soni A, Shen Y, Yin M, Zhao Y, Yu L, Hu X, Dong ZL, Khor KA, Dresselhaus MS, Xiong QH (2012) Interface driven energy filtering of thermoelectric power in spark plasma sintered Bi2Te2.7Se0.3 nanoplatelet composites. Nano Lett 12:4305–4310CrossRefGoogle Scholar
  17. 17.
    Chen ZC, Suzuki K, Miura S, Nishimura K, Ikeda K (2009) Microstructural features and deformation-induced lattice defects in hot-extruded Bi2Te3 thermoelectric compound. Mater Sci Eng A 500:70–78CrossRefGoogle Scholar
  18. 18.
    Kim SS, Yamamoto S, Aizawa T (2004) Thermoelectric properties of anisotropy-controlled p-type Bi-Te-Sb system via bulk mechanical alloying and shear extrusion. J Alloys Compd 375:107–113CrossRefGoogle Scholar
  19. 19.
    Poudel B, Hao Q, Ma Y, Lan Y, Minnich A, Yu B, Yan X, Wang DZ, Muto A, Vashaee D, Chen XY, Liu JM, Dresselhaus MS, Chen G, Ren ZF (2008) High-thermoelectric performance of nanostructured bismuth antimony telluride bulk alloys. Science 320:634–638CrossRefGoogle Scholar
  20. 20.
    Wang ZL, Akao T, Onda T, Chen ZC (2016) Microstructure and thermoelectric properties of hot-extruded Bi–Te–Se bulk materials. J Alloys Compd 663:134–139CrossRefGoogle Scholar
  21. 21.
    Wang ZL, Araki T, Onda T, Chen ZC (2017) Microstructure and its influence on thermoelectric properties of hot-extruded Bi–Sb–Te bulk materials. Scripta Mater 141:89–93CrossRefGoogle Scholar
  22. 22.
    Navrátil J, Starý Z, Plecháček T (1996) Thermoelectric properties of p-type antimony bismuth telluride alloys prepared by cold pressing. Mater Res Bull 31:1559–1566CrossRefGoogle Scholar
  23. 23.
    Zhao LD, Zhang BP, Liu WS, Zhang HL, Li JF (2009) Effects of annealing on electrical properties of n-type Bi2Te3 fabricated by mechanical alloying and spark plasma sintering. J Alloys Compd 467:91–97CrossRefGoogle Scholar
  24. 24.
    Lee DH, Lee JU, Jung SJ, Baek SH, Kim JH, Kim DI, Hyun DB, Kim JS (2014) Effect of heat treatment on the thermoelectric properties of Bismuth–Antimony–Telluride prepared by mechanical deformation and mechanical alloying. J Electron Mater 43:2255–2261CrossRefGoogle Scholar
  25. 25.
    Kim DH, Lee GH (2006) Effect of rapid thermal annealing on thermoelectric properties of bismuth telluride films grown by co-sputtering. Mater Sci Eng B 131:106–110CrossRefGoogle Scholar
  26. 26.
    Wang X, He H, Wang N, Miao L (2013) Effects of annealing temperature on thermoelectric properties of Bi2Te3 films prepared by co-sputtering. Appl Surf Sci 276:539–542CrossRefGoogle Scholar
  27. 27.
    Huang H, Luan W, Tu S (2009) Influence of annealing on thermoelectric properties of bismuth telluride films grown via radio frequency magnetron sputtering. Thin Solid Films 517:3731–3734CrossRefGoogle Scholar
  28. 28.
    Zhao Y, Dyck JS, Hernandez BM, Burda C (2010) Improving thermoelectric properties of chemically synthesized Bi2Te3-based nanocrystals by annealing. J Phys Chem C 114:11607–11613CrossRefGoogle Scholar
  29. 29.
    Cai ZK, Fan P, Zheng ZH, Liu PJ, Chen TB, Cai XM, Luo JT, Liang GX, Zhang DP (2013) Thermoelectric properties and micro-structure characteristics of annealed N-type bismuth telluride thin film. Appl Surf Sci 280:225–228CrossRefGoogle Scholar
  30. 30.
    Suga Y (1966) Thermoelectric semiconductor. Makisyoten, TokyoGoogle Scholar
  31. 31.
    Liu WS, Zhang Q, Lan Y, Chen S, Yan X, Zhang Q, Wang H, Wang DZ, Chen G, Ren ZF (2011) Thermoelectric property studies on Cu-doped n-type CuxBi2Te2.7Se0.3 nanocomposites. Adv Energy Mater 1:577–587CrossRefGoogle Scholar
  32. 32.
    Hamachiyo T, Ashida M, Hasezaki K (2009) Thermal conductivity of Bi0.5Sb1.5Te3 affected by grain size and pores. J Electron Mater 38:1048–1051CrossRefGoogle Scholar
  33. 33.
    Brown A, Lewis B (1962) The systems bismuth-tellurium and antimony-tellurium and the synthesis of the minerals hedleyite and wehrlite. J Phys Chem Solids 23:1597–1604CrossRefGoogle Scholar
  34. 34.
    Wang ZL, Akao T, Onda T, Chen ZC (2016) Formation of Te-rich phase and its effect on microstructure and thermoelectric properties of hot-extruded Bi–Te–Se bulk materials. J Alloys Compd 684:516–523CrossRefGoogle Scholar
  35. 35.
    Lotgering FK (1959) Topotactical reactions with ferrimagnetic oxides having hexagonal crystal structures—I. J Inorg Chem 9:113–123Google Scholar
  36. 36.
    Ge ZH, Ji YH, Qiu Y, Chong XY, Feng J, He J (2018) Enhanced thermoelectric properties of bismuth telluride bulk achieved by telluride-spilling during the spark plasma sintering process. Scripta Mater 143:90–93CrossRefGoogle Scholar
  37. 37.
    Tayon W, Crooks R, Domack M, Wagner J, Elmustafa AA (2010) EBSD study of delamination fracture in Al–Li Alloy 2090. Exp Mech 50:135–143CrossRefGoogle Scholar
  38. 38.
    Hu L, Zhu T, Liu X, Zhao X (2014) Point defect engineering of high-performance bismuth-telluride-based thermoelectric materials. Adv Funct Mater 24:5211–5218CrossRefGoogle Scholar
  39. 39.
    Pan Y, Wei TR, Wu CF, Li JF (2015) Electrical and thermal transport properties of spark plasma sintered n-type Bi2Te3–xSex alloys: the combined effect of point defect and Se content. J Mater Chem C 3:10583–10589CrossRefGoogle Scholar
  40. 40.
    Rai-Choudhury P, Hower PL (1973) Growth and characterization of polycrystalline silicon. J Electrochem Soc 120:1761–1766CrossRefGoogle Scholar
  41. 41.
    Kamins TI (1971) Hall mobility in chemically deposited polycrystalline silicon. J Appl Phys 42:4357–4365CrossRefGoogle Scholar
  42. 42.
    Seto JYW (1975) The electrical properties of polycrystalline silicon films. J Appl Phys 46:5247–5254CrossRefGoogle Scholar
  43. 43.
    Liu XD, Park YH (2003) Structure and transport properties of (Bi1-xSbx)2Te3 thermoelectric materials prepared by mechanical alloying and pulse discharge sintering. Mater Trans 43:681–687Google Scholar
  44. 44.
    Barnard RD (1972) Thermoelectricity in metals and alloys. Taylor and Francis, LondonGoogle Scholar
  45. 45.
    Zhang Q, Zhang QY, Chen S, Liu WS, Lukas K, Yan X, Wang HZ, Wang DZ, Opeila C, Chen G, Ren ZF (2012) Suppression of grain growth by additive in nanostructured p-type bismuth antimony tellurides. Nano Energy 1:183–189CrossRefGoogle Scholar
  46. 46.
    Ma Y, Hao Q, Poudel B, Lan YC, Yu B, Wang DZ, Chen G, Ren ZF (2008) Enhanced thermoelectric figure-of-merit in p-type nanostructured bismuth antimony tellurium alloys made from elemental chunks. Nano Lett 8:2580–2584CrossRefGoogle Scholar
  47. 47.
    Kim HS, Gibbs ZM, Tang Y, Wang H, Snyder GJ (2015) Characterization of Lorenz number with Seebeck coefficient measurement. APL Mater 3:041506CrossRefGoogle Scholar
  48. 48.
    Xu ZJ, Hu LP, Ying PJ, Zhao XB, Zhu TJ (2015) Enhanced thermoelectric and mechanical properties of zone melted p-type (Bi, Sb)2Te3 thermoelectric materials by hot deformation. Acta Mater 84:385–392CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of Mechanical and Aerospace Engineering, Graduate School of EngineeringTottori UniversityTottoriJapan

Personalised recommendations