COMPOSITE OXIDE WITH HIGH SEEBECK FACTOR AND ELECTRIC CONDUCTIVITY

摘要

PROBLEM TO BE SOLVED: To provide a material of high heat-resistance, chemical-resistance, and the like comprising an element of less toxicity and provided with a high thermoelectric conversion efficiency. SOLUTION: A composite oxide is provided which is expressed by a general expression Ca3-xRExCo4Oy (RE is rare-earth element, 0<=x<=0.5, and 8.5<=y <=10), with a Seebeck factor as 100μV/k or higher at 300 deg.C or above and electric conductivity as 103 S/m or higher.