Structure and Transport Properties of Dense Polycrystalline Clathrate-II (K,Ba)16(Ga,Sn)136 Synthesized by a New Approach Employing SPS

Materials

Xiaoyu Zeng¹  Terry M. Tritt¹  George S. Nolas²  Lilia M. Woods²  Kaya Wei²  Artem R. Khabibullin² 

[1] Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA;Department of Physics, University of South Florida, Tampa, FL 33620, USA;

关键词: clathrate;    SPS processing;    thermoelectrics;   

DOI  :  10.3390/ma9090732

来源: DOAJ

【 摘 要 】

Tin clathrate-II framework-substituted compositions are of current interest as potential thermoelectric materials for medium-temperature applications. A review of the literature reveals different compositions reported with varying physical properties, which depend strongly on the exact composition as well as the processing conditions. We therefore initiated an approach whereby single crystals of two different (K,Ba)16(Ga,Sn)136 compositions were first obtained, followed by grinding of the crystals into fine powder for low temperature spark plasma sintering consolidation into dense polycrystalline solids and subsequent high temperature transport measurements. Powder X-ray refinement results indicate that the hexakaidecahedra are empty, K and Ba occupying only the decahedra. Their electrical properties depend on composition and have very low thermal conductivities. The structural and transport properties of these materials are compared to that of other Sn clathrate-II compositions.

【 授权许可】

Unknown