High-temperature thermoelectric properties of the sintered Bi2Sr2Ca1-xYxCu2Oy (x=0-1)

Electrical conductivity and Seebeck coefficient were measured in a temperat ure range of 320-1073 K for sintered samples of Bi2Sr2Ca1-xYxCu2Oy (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0). It has been found that the conduction behavior ch anges from n-type metallic to p-type semiconducting with increasing yttrium concentration. The power factors were in a range of 1.7-3.0 x 10(-5) Wm(-1 ) K-2 for the sample with x = 0.8, being maximized by the optimization of t he yttrium concentration. The thermal conductivity for the sample with x = 0.8 was 0.73 Wm(-1) K-1 at 310 K, and decreased with increasing temperature . The values of thermoelectric figure of merit were estimated to be in a ra nge of 3.4-4.8 x 10(-5) K-1 at temperatures of 320-673 K for the sample wit h x = 0.8. (C) 2000 Kluwer Academic Publishers.