Thermoelectric properties of delafossite-related layered metal oxides

Michitaka Ohtaki, Yusuke Kubo, Koichi Eguchi

    研究成果: Contribution to conferencePaper

    14 引用 (Scopus)

    抜粋

    Thermoelectric properties of layered metal oxides NaxCoO2 in a delafossite (CuFeO2)-related crystal structure are investigated, and a possible mechanism of p-type metallic conduction leading to outstanding thermoelectric performance as an oxide is discussed in terms of crystal chemistry. Sintered samples of NaxCoO2 (x≈0.5) were prepared from Na2CO3 and Co3O4 through the conventional solid state reaction by firing in air. Probably due to losses of Na during firing, electrical properties of the oxides are revealed to be sensitive to the heating atmosphere. The oxides show almost temperature-independent electrical conductivities of >102 S cm-1 up to 1000 K, being accompanied by the positive Seebeck coefficients of 100 - 200 μV K-1 which increase linearly with temperature. Although a poor sinterability of our samples at the present state limits the conductivity to the values lower than those previously reported, the oxide shows a power factor value of >6×10-4 W m-1K-2 at 1000 K. Since the thermal conductivity of the oxides was measured as 1.5 - 2.5 W m-1K-1 at room temperature, and is usually expected to become lower at higher temperatures, the maximum figure of merit is anticipated to reach >0.4×10-3 K-1. The oxide is thereby confirmed to be the most promising p-type oxide candidate so far investigated.

    元の言語英語
    ページ559-562
    ページ数4
    出版物ステータス出版済み - 12 1 1998
    イベントProceedings of the 1998 17th International Conference on Thermoelectrics, ICT - Nagoya, Jpn
    継続期間: 5 24 19985 28 1998

    その他

    その他Proceedings of the 1998 17th International Conference on Thermoelectrics, ICT
    Nagoya, Jpn
    期間5/24/985/28/98

    All Science Journal Classification (ASJC) codes

    • Engineering(all)

    フィンガープリント Thermoelectric properties of delafossite-related layered metal oxides' の研究トピックを掘り下げます。これらはともに一意のフィンガープリントを構成します。

  • これを引用

    Ohtaki, M., Kubo, Y., & Eguchi, K. (1998). Thermoelectric properties of delafossite-related layered metal oxides. 559-562. 論文発表場所 Proceedings of the 1998 17th International Conference on Thermoelectrics, ICT, Nagoya, Jpn, .