Control of crystallographic orientation and grain refinement in Bi 2Te3-based thermoelectric semiconductors by applying high pressure torsion

Maki Ashida, Takashi Hamachiyo, Kazuhiro Hasezaki, Hirotaka Matsunoshita, Masaaki Kai, Zenji Horita

Research output: Chapter in Book/Report/Conference proceedingConference contribution

11 Citations (Scopus)

Abstract

Prepared were p-type Bi2Te3-based thermoelectric semiconductors, having a grain-refined microstructure and a preferred orientation of anisotropic crystallographic structure. Disks with a nominal composition Bi0.5Sb1.5Te3.0 were cut from an ingot grown by the vertical Bridgman method (VBM) and deformed at 473 K under a pressure of 6.0 GPa by high pressure torsion (HPT). The crystal orientation was characterized with X-ray diffraction. The microstructures were characterized by using optical microscopy and scanning electron microscopy. It was found that the HPT disks had a fine and preferentially oriented grain compared to that of the VBM disks. Further, the power factor of the HPT disks was about twice as large as that of the VBM disks. These results indicate that HPT is effective for improving the thermoelectric properties of Bi2Te3-based thermoelectric semiconductors.

Original languageEnglish
Title of host publicationMaterials Science Forum - Nanomaterials by Severe Plastic Deformation 4 - 4th International Conference on Nanomaterials by Severe Plastic Deformation
PublisherTrans Tech Publications Ltd
Pages1006-1011
Number of pages6
Volume584-586 PART 2
ISBN (Print)9770255547605
Publication statusPublished - 2008
Event4th International Conference on Nanomaterials by Severe Plastic Deformation - Goslar, Germany
Duration: Aug 18 2008Aug 22 2008

Publication series

NameMaterials Science Forum
Volume584-586 PART 2
ISSN (Print)02555476

Other

Other4th International Conference on Nanomaterials by Severe Plastic Deformation
CountryGermany
CityGoslar
Period8/18/088/22/08

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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  • Cite this

    Ashida, M., Hamachiyo, T., Hasezaki, K., Matsunoshita, H., Kai, M., & Horita, Z. (2008). Control of crystallographic orientation and grain refinement in Bi 2Te3-based thermoelectric semiconductors by applying high pressure torsion. In Materials Science Forum - Nanomaterials by Severe Plastic Deformation 4 - 4th International Conference on Nanomaterials by Severe Plastic Deformation (Vol. 584-586 PART 2, pp. 1006-1011). (Materials Science Forum; Vol. 584-586 PART 2). Trans Tech Publications Ltd.