Affiliation: | aDepartment of Materials Science and Engineering, Kochi National College of Technology, 200-1 Monobe, Nankoku 783-8508, Japan bKochi Prefectural Industrial Technology Center, 3992-3 Nunoshida, Kochi 781-5101, Japan |
Abstract: | La- and K-doped perovskite-type ceramics, (Sr0.6Ba0.4)1−xLaxPbO3 with x = 0.0−0.1 and (Sr0.6Ba0.4)1−xKxPbO3 with x = 0.00−0.15, were prepared to modify thermoelectric properties of semi-metallic Sr0.6Ba0.4PbO3 via the doping of electrons and holes, respectively. The electrical conductivity σ and Seebeck coefficient S for the ceramics were measured at temperatures of 373–1073 K in air. With the La doping, electron carriers were successively doped and the material changed from a semi-metal for the undoped Sr0.6Ba0.4PbO3 to a metal for the (Sr0.6Ba0.4)0.9La0.1PbO3. With the K doping, the thermoelectric properties were essentially unchanged probably due to the carrier compensation effect by the generation of oxygen deficiencies. The thermoelectric power factor S2σ was maximized to a value of 3.1 × 10−4 Wm−1 K−2 at 773 K for the undoped Sr0.6Ba0.4PbO3 ceramic. |