Structure and high-temperature thermoelectric properties of SrAl2Si2

Susan M. Kauzlarich, Cathie L. Condron, Jonathan K. Wassei, Teruyuki Ikeda, G. Jeffrey Snyder

Research output: Contribution to journalArticle

28 Scopus citations

Abstract

Single crystals of SrAl2Si2 were synthesized by reaction of the elements in an aluminum flux at 1000 °C. SrAl2Si2 is isostructural to CaAl2Si2 and crystallizes in the hexagonal space group P-3m1 (90 K, a=4.1834 (2), c=7.4104 (2) Å, Z=1, R1=0.0156, wR2=0.0308). Thermal analysis shows that the compound melts at ∼1020 °C. Low-temperature resistivity on single crystals along the c-axis shows metallic behavior with room temperature resistivity value of ∼7.5 mΩ cm. High-temperature Seebeck, resistivity, and thermal conductivity measurements were made on hot-pressed pellets. The Seebeck coefficient shows negative values in entire temperature range decreasing from ∼-78 μV K-1 at room temperature to -34 μV K-1 at 1173 K. Seebeck coefficients are negative indicating n-type behavior; however, the temperature dependence is consistent with contribution from minority p-type carriers as well. The lattice contribution to the thermal conductivity is higher than for clathrate structures containing Al and Si, approximately 50 mW cm-1 K, and contributes to the overall low zT for this compound.

Original languageEnglish (US)
Pages (from-to)240-245
Number of pages6
JournalJournal of Solid State Chemistry
Volume182
Issue number2
DOIs
StatePublished - Feb 2009

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Keywords

  • Aluminum silicide
  • CaAlSi
  • High-temperature thermoelectric material
  • Silicides
  • Strontium
  • Ternary phase
  • Thermal conductivity
  • Thermoelectric
  • Zintl
  • ZT

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Inorganic Chemistry
  • Physical and Theoretical Chemistry
  • Ceramics and Composites
  • Electronic, Optical and Magnetic Materials
  • Materials Chemistry

Cite this

Kauzlarich, S. M., Condron, C. L., Wassei, J. K., Ikeda, T., & Snyder, G. J. (2009). Structure and high-temperature thermoelectric properties of SrAl2Si2 Journal of Solid State Chemistry, 182(2), 240-245. https://doi.org/10.1016/j.jssc.2008.09.028