The thermoelectric properties of [Ca2CoO3]0.62[CoO2] textured ceramics

Author

Huang, X.Y. ; Miyazaki, Y. ; Yubuta, K. ; Oide, Y. ; Kajitani, Tsutomu

Author_Institution

Core Res. for Evolutional Sci. & Technol., Japan Sci. & Technol. Agency, Tokyo

fYear

2006

fDate

6-10 Aug. 2006

Firstpage

89

Lastpage

91

Abstract

Large and high-quality single crystal flakes of [Ca₂CoO ₃]_0.62[CoO₂] compound were grown from Co₃O₄ and CaCO₃ reagents with chloride flux. Typical single crystal flake size is about 5times5times0.02 mm ³. Obtained crystal flakes were consolidated by the spark plasma sintering (SPS) technique at 1100 K for 1 h. Grain alignment was checked by XRD and also was confirmed by SEM observations on the fractured surface. At 1000 K electrical conductivity of the textured ceramics is about 270 Scm^-1, twice as higher than that of powder sample sintered by the SPS procedure. ZT value of the textured sample reaches 0.4 at 1000 K, being 50% improvement relative to the powder-sintered sample, though thermal conductivity increases simultaneously

Keywords

X-ray diffraction; calcium compounds; ceramics; crystal growth from solution; crystal orientation; electrical conductivity; plasma materials processing; scanning electron microscopy; sintering; thermal conductivity; thermoelectricity; 1 h; 1000 K; 1100 K; CaCO₃ reagent; Co₃O₄ reagent; SEM; SPS technique; XRD; [Ca₂CoO₃]_0.62[CoO₂]; chloride; crystal growth; fractured surface; grain alignment; single crystal flake size; spark plasma sintering technique; textured ceramic ZT value; textured ceramic electrical conductivity; textured ceramic thermoelectric properties; thermal conductivity; Ceramics; Conducting materials; Crystal microstructure; Crystalline materials; Grain size; Plasma temperature; Powders; Semiconductor materials; Thermal conductivity; Thermoelectricity;

fLanguage

English

Publisher

ieee

Conference_Titel

Thermoelectrics, 2006. ICT '06. 25th International Conference on

Conference_Location

Vienna

ISSN

1094-2734

Print_ISBN

1-4244-0811-3

Electronic_ISBN

1094-2734

Type

conf

DOI

10.1109/ICT.2006.331287

Filename

4133243