Improvement on the high temperature thermoelectric performance of Ga-doped misfit-layered Ca3Co4-xGaxO9+δ (x = 0, 0.05, 0.1, and 0.2)

N. V. Nong, Chia-Jyi Liu, M. Ohtaki

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Abstract

Highly densified Ca3Co4-xGaxO9+δ (0 ≤ x ≤ 0.2) misfit-layered thermoelectric oxides are prepared by solid state reaction methods followed by hot-pressing. Thermoelectric properties of the samples are measured from room temperature to 1200 K. The results show that partial Ga substitution leads to a simultaneous increase of the electrical conductivity and thermopower. The Ga-doped samples have lower thermal conductivity than that of the non-doped sample in the high temperature region (>600 K). The x = 0.05 sample shows a higher figure of merit (Z = 3.37 × 10-4 K-1) than that of the non-doped sample (Z = 1.98 × 10-4 K-1) at 1073 K, indicating significant improvement of the thermoelectric performance of Ca3Co4O9+δ by partial Ga substitution for Co.

Original languageEnglish
Pages (from-to)53-56
Number of pages4
JournalJournal of Alloys and Compounds
Volume491
Issue number1-2
DOIs
Publication statusPublished - 2010 Feb 18

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All Science Journal Classification (ASJC) codes

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

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