Crystal structure and thermoelectric properties of the composite crystal [(Ca1-xSrx)2CoO3]pCoO2

Y. Miyazaki, T. Miura, Y. Ono, T. Akashi, T. Goto, T. Kajitani

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

9 Citations (Scopus)

Abstract

Polycrystalline samples of [(Ca1-xSrx)2CoO3]pCoO2 with 0 ≤5 x≤0.25 have been synthesized at 920°C in flowing oxygen gas. The modulated crystal structure of the samples has been determined in accordance with a four-dimensional formalism from powder neutron diffraction data. With increasing x, the modulation amplitudes in Co-Co conduction paths become less marked. The non-doped sample (x=0) exhibits the resistivity ρ =15 mΩcm and the thermoelectric power S=130 μV/K at 300 K. Both the ρ and S values decrease with x but the decrease in ρ values is steeper than that of the S values. The power factor S2/ρ increases with x, from 1.1×10-4 W/mK2 (x=0) to 1.4×10-4 W/mK2 (x=0.20) at 300 K. This improvement in thermoelectric performance can be explained in terms of the reduction of displacive modulation of the Co-Co conduction paths in the CoO2 sheets.

Original languageEnglish
Title of host publicationProceedings ICT 2002
Subtitle of host publication21st International Conference on Thermoelectrics
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages226-229
Number of pages4
ISBN (Electronic)0780376838
DOIs
Publication statusPublished - 2002
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
Country/TerritoryUnited States
CityLong Beach
Period02/8/2502/8/29

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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