Preparation and thermoelectric properties of AgPb_(18-x)Sn_xSbTe_(20) (x = 0.5,1, 2, 4, 6) materials

摘要

AgPb_(18-x)Sn_xSbTe_(20) {x = 0.5,1,2,4,6) bulk samples were prepared by hydrothermal synthesis followed by melting. All the samples are in NaCl-type structure and their lattice constant decreases with increase of x value. The thermoelectric properties of the as-prepared samples were investigated in the temperature range of ～ 300-773 K. The electrical conductivity of the samples initially decreases and then increases with the increase of Sn content (x). The AgPb_(18-x)Sn_xSbTe_(20) (x = 0.5,1,2) samples show n-type conduction in the whole temperature range measured, while the AgPb_(18-x)Sn_xSbTe_(20) (x=4, 6) samples change from p- to n-type conduction at ～ 520 and 650 K, respectively. For the AgPb_(17)SnSbTe_(20) sample, a maximum ZT value of 0.72 was achieved at 623 K.