Thermoelectric Properties of Pulsed Electric Current Sintered Samples of AgPb m SbSe17 (m = 16 or 17)

Abstract

Lead chalcogenide materials have drawn attention in recent years because of their outstanding thermoelectric properties. Bulk n-type materials of AgPbmSbTe2+m have been reported to exhibit high figure of merit, ZT, as high as 1.7 at 700 K. Recent reports have shown p-type lead selenide-based compounds with comparable ZT. The analogous material AgPbmSbSe17 shares a similar cubic rock-salt structure with PbTe-based compounds; however, it exhibits a higher melting point, and selenium is more abundant than tellurium. Using solid solution chemistry, we have fabricated cast AgPb15SbSe17 samples that show a peak power factor of approximately 17 μW/cm K2 at 450 K. Increasing the strength of such materials is commonly achieved through powder processing, which also helps to homogenize the source materials. Pulsed electric current sintering (PECS) is a hot-pressing technique that utilizes electric current through the die and sample for direct Joule heating during pressing. The mechanisms present during PECS processing have captured significant research interest and have led to some notable improvements in sample properties compared with other densification techniques. We report the thermoelectric properties of PECS samples of AgPbmSbSe17 along with sample fabrication and processing details.