Nonlinear thermoelectric properties of layered cobalt oxides

Tomohito Nakano, Wataru Kobayashi, Ryoji Funahashi, Kenji Sugiura, Hiromichi Ohta, Kunihito Koumoto, Ichiro Terasaki

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

    Abstract

    We synthesized whisker-crystal and thin-film samples of the layered cobalt oxide (Bi2Sr2O4)xCoO2 well known as a candidate of a thermoelectric material, and measured their resistivity, voltage-current characteristics and magnetoresistance with pulsed currents. Resistivity of the whisker sample with a small current density of 2 mA/cm2 increases with decreasing temperature below 100 K, suggesting development of a pseudogap on the density of states. This increase is suppressed by a large current density of 110 A/cm2. The nonlinear voltage-current characteristics are observed both for the whisker and thin-film samples. The negative magnetoresistance of the thin-film sample is suppressed by current density. These suggest that the density of states recovers owing to the suppression of the pseudogap by applying large current density.

    Original languageEnglish
    Title of host publicationProceedings ICT'07 - 26th International Conference on Thermoelectrics
    Pages121-123
    Number of pages3
    DOIs
    Publication statusPublished - 2007
    EventICT'07 - 26th International Conference on Thermoelectrics - Jeju, Korea, Republic of
    Duration: 2007 Jun 32007 Jun 7

    Other

    OtherICT'07 - 26th International Conference on Thermoelectrics
    CountryKorea, Republic of
    CityJeju
    Period07/6/307/6/7

    ASJC Scopus subject areas

    • Engineering(all)

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