Session: Solid-State Inorganic Chemistry:

A few compounds with polar crystal structures existing in the Ag/Cu-Ge-Q (Q = S, Se, Te) phase diagrams have been reported as promising thermoelectric materials with low thermal conductivities. Ag₂GeS₃was identified as another promising thermoelectric compound based on its polar crystal structure (space group Cmc21) and relationship with previously reported thermoelectric materials. Polycrystalline Ag₂GeS₃sample was synthesized through a simple one-step solid-state method at high temperature and consolidated into a dense pellet via spark plasma sintering (SPS). The high-temperature thermoelectric properties measurements reveal a very low thermal conductivity of the dense pellet. A possible structural conversion from Ag₂GeS₃to Ag₁₀Ge₃S₁₁ and GeS₂ was observed during the SPS process. The thermal stability of Ag₂GeS₃ is currently under further investigation with in-situ synchrotron powder X-ray diffraction technique in addition to the thermogravimetric analysis and differential scanning calorimetry measurements. Density functional theory calculations will be preformed to understand the origin of the low thermal conductivity and compare it with the experimental result.

Susan Kauzlarich

Appearances