Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9781768 | Journal of Physics and Chemistry of Solids | 2005 | 5 Pages |
Abstract
Polycrystalline samples of Ca3Co2O6-based solid solutions, (Ca1âxBix)3Co2O6, Ca3(Co1âxCux)2O6 and (Ca1âxBix)3(Co1âxCux)2O6, were prepared by solid state reaction at 1243 K in air. The single phases were obtained at xâ¤0.02 for (Ca1âxBix)3Co2O6, Ca3(Co1âxCux)2O6 and (Ca1âxBix)3(Co1âxCux)2O6, and the lattice parameters increased with increasing x. The electrical resistivity (Ï) of the solid solutions exhibited semiconducting behavior in 300-1170 K, and the values of electrical resistivity decreased with increasing x (3.8Ã10â2 Ωcm for (Ca0.98Bi0.02)3Co2O6, 5.7Ã10â2 Ωcm for Ca3(Co0.98Cu0.02)2O6 and 4.8Ã10â2 Ωcm for (Ca0.98Bi0.02)3(Co0.98Cu0.02)2O6 at 1170 K). Seebeck coefficient (S) of the solid solutions were smaller than that of Ca3Co2O6 below 800 K, however, the values were almost the same as that of Ca3Co2O6 (around 140 μV/K) above 1000 K. The power factor (S2/Ï) tended to increase with increasing temperature and x, and the maximum values were 5.0Ã10â5 W/(m K2) for (Ca0.98Bi0.02)3Co2O6, 3.7Ã10â5 W/(m K2) for Ca3(Co0.98Cu0.02)2O6 and 4.0Ã10â5 W/(m K2) for (Ca0.98Bi0.02)3(Co0.98Cu0.02)2O6 at 1170 K.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
Kouta Iwasaki, Hisanori Yamane, Junichi Takahashi, Shunichi Kubota, Takanori Nagasaki, Yuji Arita, Yoshimasa Nishi, Tsuneo Matsui, Masahiko Shimada,