RECENT INVESTIGATIONS OF Sr-Ca-Co-O THERMOELECTRIC MATERIALS

Published

December 21, 2009

Author(s)

Winnie K. Wong-Ng, Guangyao Liu, Makoto Otani, Evan L. Thomas, Nathan Lowhorn, Martin L. Green, James A. Kaduk

Abstract

Three low-dimension cobaltites in the Sr-Ca-Co-O system have been studied for their structure and thermoelectric properties. Using x-ray pole figure construction technique, a Ca3Co4O9 thin film showed excellent fiber texture but no ab in-plane texture. The fiber texture is mainly responsible for the excellent thermoelectric properties. Our study of a high-throughput combinatorial thin film (synthesized using Pulsed Laser Deposition) with a custom-built power factor screening tool demonstrated that the La substitution in the Ca-site of Ca3Co4O9 increases Seebeck coefficient and resistivity due to decrease of hole concentration. The Sr-substitution on the Ca-site increases the carrier mobility, therefore lower resistivity of the film. The homologous compounds Can+2ConCo O3n+3 and Srn+2ConCo O3n+3 consist of parallel 1-dimensional (Co2O6)6- chains that are built by successive alternating face-sharing CoO6 trigonal prism and n units of CoO6 octahedra along the c-axis. However, due to the high resistivity of these compounds, they will unlikely yield ZT values comparable to that of Ca3Co4O9.

Proceedings Title

International Symposium on Advanced Dielectric Materials and Electronic Devices

Conference Dates

October 5-10, 2008

Conference Location

Pittsburgh, PA

Conference Title

Materials Science and Technology 2008 Conference and Exhibit (MS&T08)

Pub Type

Conferences

Keywords

thermoelectric, Ca3Co4O9, Can+2ConCo O3n+3, Srn+2ConCo O3n+3

Citation

Wong-Ng, W. , Liu, G. , Otani, M. , Thomas, E. , Lowhorn, N. , Green, M. and Kaduk, J. (2009), RECENT INVESTIGATIONS OF Sr-Ca-Co-O THERMOELECTRIC MATERIALS, International Symposium on Advanced Dielectric Materials and Electronic Devices, Pittsburgh, PA (Accessed December 30, 2024)