Effect of Ag addition on the thermoelectric properties of Bi1.6Pb0.4Sr2Co1.8Oy thermoelectric textured materials

Abstract

Bi1.6Pb0.4Sr2Co1.8Oy/Ag composites with small amounts of Ag (0, 1 and 3wt.%) have been synthesized by a sol‐gel via nitrates reaction and directionally grown from the melt. As‐grown samples were microstructurally characterized to determine the phases distribution and alignment. Moreover, thermoelectric characteristics were determined by the four‐probe technique. Scanning electron microscopy revealed that Ag particles appear dispersed among well oriented ceramic grains with large size. The composites electrical resistivity is lower than that of pure Bi1.6Pb0.4Sr2Co1.8Oy. The resistivity reduction leads to power factor improvements higher than 50%, compared with pure samples, for Ag additions of 3wt.%Ag.