Electrical properties of Ag1−xPb18SbTe20 (x = 0, 0.1, 0.3)

A sintered polycrystalline sample of Ag1−xPb18SbTe20 (x = 0, 0.1, 0.3) was prepared by a solid-state reaction. The electrical resistivity and Seebeck coefficient were measured from room temperature to about 800 K. The electrical resistivity of Ag1−xPb18SbTe20 (x = 0, 0.1, 0.3) decreases with increasing Ag content. The values of the electrical resistivity are of the order of 10−4 Ω m. The Seebeck coefficient of Ag1Pb18SbTe20 is positive up to 420 K, however, it changes to negative from 420 to 800 K. The absolute value of the Seebeck coefficient of Ag1−xPb18SbTe20 (x = 0.1, 0.3) at 373 K is 404 and 320 μV K−1, respectively, which is twice as high as that of state-of-the-art thermoelectric materials.