Title :
Thermoelectric properties of CaMnO3 system
Author :
Funahashi, R. ; Kosuga, A. ; Miyasou, N. ; Takeuchi, E. ; Urata, S. ; Lee, K. ; Ohta, H. ; Koumoto, K.
Author_Institution :
Nat. Inst. of Adv. Ind. Sci.&Tech., Ikeda
Abstract :
Ca1-xRExMnO3 (RE: Nd, Tb, Ho, Yb, Lu, x = 0.1 and 0.2) bulks were prepared by a solid state reaction. They show metallic behavior at temperatures higher than about 400 K and electrical resistivity rho is lower than 12 mOmega cm at 1000 K in air. Absolute values of Seebeck coefficient S increases with temperature up to 973 K for all samples except Ca0.9Yb0.1MnO3 at 973 K. For Ca0.9Lu0.1MnO3, S value reaches -130 muV/K at 973 K. Both thermoelectric properties are dominated mainly by crystallographic structure. Power factor PF (=S2/rho) increases with decreasing cell volume. Thermal conductivity kappa of Yb- and Lu-substituted samples is as low as 1.5 W/m-K2 and dimension-less figure of merit ZT reaches 0.16 at 973 K for Ca0.8Lu0.2MnO3 in air.
Keywords :
Seebeck effect; calcium compounds; crystal structure; electrical resistivity; holmium compounds; lutetium compounds; neodymium compounds; terbium compounds; thermal conductivity; thermoelectric power; ytterbium compounds; Ca0.8Lu0.2MnO3; Ca0.9Lu0.1MnO3; Ca0.9Yb0.1MnO3; Ca1-xHoxMnO3; Ca1-xNdxMnO3; Ca1-xTbxMnO3; Seebeck coefficient; cell volume; crystallographic structure; dimension-less figure of merit; electrical resistivity; metallic state; power factor; solid state reaction method; temperature 1000 K; temperature 973 K; thermal conductivity; thermoelectric properties; Atmospheric measurements; Crystallography; Electric resistance; Neodymium; Powders; Solid state circuits; Temperature; Thermal conductivity; Thermoelectricity; Voltage;
Conference_Titel :
Thermoelectrics, 2007. ICT 2007. 26th International Conference on
Conference_Location :
Jeju Island
Print_ISBN :
978-1-4244-2262-3
Electronic_ISBN :
1094-2734
DOI :
10.1109/ICT.2007.4569439
