Zevalkink Alex, Chanakian Sevan, Aydemir Umut, Ormeci Alim, Pomrehn Gregory, Bux Sabah, Fleurial Jean-Pierre, Snyder G Jeffrey
Department of Applied Physics and Materials Science, California Institute of Technology, 1200 E California Blvd, Pasadena, CA, USA. Thermal Energy Conversion Technologies Group, Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA, USA.
J Phys Condens Matter. 2015 Jan 14;27(1):015801. doi: 10.1088/0953-8984/27/1/015801. Epub 2014 Dec 5.
The Zintl phase Sr5In2Sb6 is isostructural with Ca5In2Sb6-a promising thermoelectric material with a peak zT of 0.7 when the carrier concentration is optimized by doping. Density functional calculations for Sr5In2Sb6 reveal a decreased energy gap and decreased valence band effective mass relative to the Ca analog. Chemical bonding analysis using the electron localizability indicator was found to support the Zintl bonding scheme for this structure type. High temperature transport measurements of the complete Ca(5-x)Sr(x)In2Sb6 solid solution were used to investigate the influence of the cation site on the electronic and thermal properties of A5In2Sb6 compounds. Sr was shown to be fully miscible on the Ca site. The higher density of the Sr analog leads to a slight reduction in lattice thermal conductivity relative to Ca5In2Sb6, and, as expected, the solid solution samples have significantly reduced lattice thermal conductivities relative to the end member compounds.
津特耳相Sr5In2Sb6与Ca5In2Sb6同构，Ca5In2Sb6是一种很有前景的热电材料，通过掺杂优化载流子浓度时，其峰值zT为0.7。对Sr5In2Sb6的密度泛函计算表明，相对于钙类似物，其能隙减小，价带有效质量降低。使用电子定域性指标进行的化学键分析被发现支持这种结构类型的津特耳键合方案。对完整的Ca(5-x)Sr(x)In2Sb6固溶体进行高温输运测量，以研究阳离子位点对A5In2Sb6化合物电子和热性能的影响。结果表明，Sr在Ca位点上完全可混溶。相对于Ca5In2Sb6，Sr类似物的较高密度导致晶格热导率略有降低，并且，正如预期的那样，固溶体样品相对于端元化合物的晶格热导率显著降低。
