Investigation of Preparation and Thermoelectric Properties of Ca2.5La0.5Co4O9 Porous Ceramics

CO(NH2)2 as pore-former used to prepare porous Ca2.5La0.5Co4O9 thermoelectric materialsby solid-state reaction technique.Microstructure,density and thermoelectric properties (temperature dependence of electrical resistivity,Seebeck coefficient) of the samples were studied in details.The results have shown that the porosity increases and the pore structure is improved with the pore-former content increasing,and electrical resistivity and density decrease while Seebeck coefficient raise.The improvement in electrical resistivity and Seebeck coefficient leads to higher power factor values at 913 K (around 1.32 mW/cm·K2) than undoped samples.