High temperature thermoelectric properties of co-doped Ca3xAgxCo3.95Fe0.05O9+δ (0≤x≤0.3)》.pdf

Available online at CERAMICS INTERNATIONAL Ceramics International 41 (2015) 10456– 10460 /locate/ceramint High temperature thermoelectric properties of co-doped Ca Ag Co Fe O (0 rx r0.3) 3 x x 3.95 0.05 9 þ δ Ankam Bhaskar, Zong-Ren Yang, Chia-Jyi Liun Department of Physics, National Changhua University of Education, Changhua 500, Taiwan Received 28 March 2015; received in revised form 19 April 2015; accepted 21 April 2015 Available online 7 May 2015 Abstract We have fabricated a series of co-doped misfit-layered cobaltites Ca Ag Co Fe O with x ¼0.0, 0.1, 0.2 and 0.3 using conventional 3 x x 3.95 0.05 9 þ δ solid state reaction. The electrical resistivity and thermopower were measured between 300 and 700 K. For all the samples, the temperature dependence of electrical resistivity exhibits broad maximum. The level-off thermopower behavior of misfit-layered cobaltites in the temperature range of 200 and 300 K is often observed. Instead, the thermopower of Ca