Comparison for thermoelectric properties of BiTe based semiconductor processed by the mechanical alloying and the high pressure torsion after melt grown by the vertical Bridgman method

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

    研究成果: Chapter in Book/Report/Conference proceedingConference contribution

    抄録

    Bi2Te3-related thermoelectric semiconductors were prepared by the mechanical alloying (MA) and the vertical Bridgman (VBM) - High Pressure Torsion (HPT) methods. Structures and electric properties of these alloys were then investigated. These samples had a nominal composition of Bi0.5Sb1.5Te3.0 with 0.07 mass% excess Te. The MA sample was sintered into a compact after mechanical alloying by hot-pressing while the VBM - HPT sample was subjected by HPT after being cut into a disk from a melt-grown ingot by the vertical Bridgman method (VBM). The orientation factors of the MA and VBM - HPT samples were 0.054 and 0.525, respectively, indicating that the preferred orientation was formed by VBM - HPT. Average grain sizes of both samples were approximately 2 μm. By estimating the slope of carrier mobility versus temperature the carrier scattering factor of the MA and VBM - HPT samples were estimated to be -2.8 and -1.4. These values are indicative of carrier scatterings by acoustic phonons and by the interaction between acoustic and optical phonons, respectively. The maximum power factor obtained for the isotropic MA sample was 4.1 × 10-3W m -1 K-2 at 310 K and this was about twice the 2.1 × 10-3W m-1 K-2 at 440K obtained for the anisotropic VBM - HPT sample.

    本文言語英語
    ホスト出版物のタイトルTHERMEC 2009
    編集者Tara Chandra, Tara Chandra, Tara Chandra, N. Wanderka, N. Wanderka, N. Wanderka, Walter Reimers, Walter Reimers, Walter Reimers, M. Ionescu, M. Ionescu, M. Ionescu
    出版社Trans Tech Publications Ltd
    ページ1923-1928
    ページ数6
    ISBN(印刷版)0878492941, 9780878492947
    DOI
    出版ステータス出版済み - 2010
    イベント6th International Conference on Processing and Manufacturing of Advanced Materials - THERMEC'2009 - Berlin, ドイツ
    継続期間: 8 25 20098 29 2009

    出版物シリーズ

    名前Materials Science Forum
    638-642
    ISSN(印刷版)0255-5476
    ISSN(電子版)1662-9752

    その他

    その他6th International Conference on Processing and Manufacturing of Advanced Materials - THERMEC'2009
    Countryドイツ
    CityBerlin
    Period8/25/098/29/09

    All Science Journal Classification (ASJC) codes

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

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