Microstructures and Thermoelectric Properties of Sintered Misfit-Layered Cobalt Oxide

作者：Morimura Takao^*; Yamaguchi Takahiro; Kojima Takuya; Matsuya Noriki; Kondo Shin Ichiro; Nakashima Hiromichi

来源：Journal of Electronic Materials, 2014, 43(6): 1603-1607.

DOI：10.1007/s11664-013-2805-7

• Seebeck coefficient
• dimensionless figure of merit
• degree of orientation
• Lotgering factor
• Harman method

Misfit-layered cobalt oxide Ca3Co4O9 is considered to be a prospective material for thermoelectric conversion. The thermoelectric properties are anisotropic owing to its anisotropic crystal structure. The crystal has preferred thermoelectric properties along the a-b plane. Therefore, the thermoelectric properties are improved and controlled by the degree of orientation of the sintered sample. In the present work, Sr-doped misfit cobalt oxide Ca2.7Sr0.3Co4O9 was prepared by solid-phase reaction, followed by uniaxial compression molding and sintering at 1173 K. The Seebeck coefficient alpha, electrical resistivity rho, and dimensionless figure of merit ZT were measured as a function of the compression pressure applied in the uniaxial molding. alpha, rho, and ZT as functions of the degree of orientation and the relative density are experimentally clarified and explained by calculations using the compound model.

• 出版日期2014-6