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
    ISBN (Electronic)978-0-87849-360-9
    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)0255-5476
    ISSN (Electronic)1662-9752

    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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