Title :
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
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;
Conference_Titel :
Thermoelectrics, 2006. ICT '06. 25th International Conference on
Conference_Location :
Vienna
Print_ISBN :
1-4244-0811-3
Electronic_ISBN :
1094-2734
DOI :
10.1109/ICT.2006.331287
