Development of new-type cobalt oxide thermoelectric materials

T. Kajitani, Y. Ono, Y. Miyazaki, Y. Morii

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

3 Citations (Scopus)

Abstract

Single phase cobalt oxide thermoelectric materials, AxCoO2 with A=Na,Sr, Ca and Ba, [A'2CoO3]z[CoO2] with A'=Ca,Sr(349-phase), z=0.62 and [Ca2(CO1-yCuy)2O4]z[CoO2] with y=0.33 are synthesized successfully by the ion-exchange method or solid state reaction method. Seebeck coefficient, electric resistivity and magnetization of these oxides are measured in the temperature range from 4K to 300K. These cobalt oxides show p-type conductivity and relatively high positive Seebeck coefficient, i.e., about 120 μV/K or above at 300K. The electric resistivity of sintered samples has been measured at the level of 10 m?cm at 300K. New nomenclature, the naming system, of modulated layered cobalt oxide thermoelectric materials, e.g., the latter two ones, is proposed according to the numbers of stacking cation layers, namely Co-121 for [Ca2CoO3]0.62[CoO2] , Co(Cu)-221 for [Ca2(Co1-yCuy)2O4]z[CoO2] and Bi-221 for [Bi0.87SrO2]2[CoO2]1.82, respectively. The top letter is the cation(s) sitting in the rocksalt layer(s). The 1st, 2nd and 3rd digits indicate the numbers of the rocksalt-type metal - Oxygen layer(s), alkali earth metal - Oxygen layer(s) and conducting triangle cobalt oxygen layer(s) in a unit cell, respec-tively.

Original languageEnglish
Title of host publicationProceedings ICT 2002
Subtitle of host publication21st International Conference on Thermoelectrics
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages195-198
Number of pages4
ISBN (Electronic)0780376838
DOIs
Publication statusPublished - 2002 Jan 1
Event21st International Conference on Thermoelectrics, ICT 2002 - Long Beach, United States
Duration: 2002 Aug 252002 Aug 29

Publication series

NameInternational Conference on Thermoelectrics, ICT, Proceedings
Volume2002-January

Other

Other21st International Conference on Thermoelectrics, ICT 2002
CountryUnited States
CityLong Beach
Period02/8/2502/8/29

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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