Investigation on the preparation and thermoelectric properties of layered SrAl2Ge2

Abstract:

II, III and IV groups were widely investigated to synthesize guest-host thermoelectric compounds in order to obtain high optimal ZT value materials. While a novel layered structure was less reported for Sr-Al-Ge system. In this study, SrAl2Ge2 single crystal was grown by aluminum flux at 1150℃ and characterized by powder X-ray methods. It is isotropic and crystallize in the CaAl2Si2-type structure through the Rietveld refinement method (space group P3-m1) with the lattice constants a=b=4.2339(1) Å, c=7.4809(0) Å. Temperature-depended resistivity on single crystals along the c-axis shows p-type semiconducting behavior. Heat capacity (Cp) was measured in 2-300 K and low temperature Cp was consistent with data calculated by using Debye model. This work opens up a novel avenue for seeking and designing environment-friendly and high-performance thermoelectric materials.