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Synthesis and thermoelectric characterization of polycrystalline Ni1−xCa x Co2O4 (x=0–0.05) spinel materials

  • Yoshinobu Fujishiro
  • Kouich Hamamoto
  • Osamu Shiono
  • Shingo Katayama
  • Masanobu Awano
Article

Abstract

Ca doped NiCo2O4 spinel materials were synthesized by conventional solid state reactions at 900 °C. Thermoelectric properties of polycrystalline products were characterized at high temperature range of ∼800 °C in air. d.c. conductivity of the prepared polycrystalline 5 mol % Ca doped NiCo2O4 was about 60 S m−1 at 300 °C. The value of d.c. conductivity was increased with the temperature increasing. Thermoelectric voltage of polycrystalline Ni1−xCa x Co2O4 (x=0–0.05) was positive at 300–800 °C, this showed p-type thermoelectric properties. The Seebeck coefficient of 5 mol % Ca doped NiCo2O4 was ca. 300 μV/K at 600 °C. The value of the Seebeck coefficient of Ni1−xCa x Co2O4 polycrystalline products decreased with the increasing temperature. Thermal conductivity of 5 mol % Ca doped NiCo2O4 was ca. 2.2 W m−1 K−1 at 600 °C. The estimated thermoelectric figure-of-merit, Z, of 5 mol % Ca doped NiCo2O4 spinel polycrystalline product was about 3.5×10−5 K−1 at 600 °C.

Keywords

Thermal Conductivity Solid State Electronic Material Solid State Reaction Thermoelectric Property 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Kluwer Academic Publishers 2004

Authors and Affiliations

  • Yoshinobu Fujishiro
    • 1
  • Kouich Hamamoto
    • 1
  • Osamu Shiono
    • 2
  • Shingo Katayama
    • 2
  • Masanobu Awano
    • 1
  1. 1.Research Center of Synergy Materials, AISTNagoyaJapan
  2. 2.Synergy Ceramics LaboratoryFine Ceramics Research Association (FCRA), Joint Research Center for Advanced TechnologyNagoyaJapan

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