Elastic modulus, biaxial fracture strength, electrical and thermal transport properties of thermally fatigued hot pressed LAST and LASTT thermoelectric materials

A. Q. Morrison, E. D. Case*, F. Ren, A. J. Baumann, D. C. Kleinow, J. E. Ni, T. P. Hogan, J. D'Angelo, N. A. Matchanov, T. J. Hendricks, N. K. Karri, C. Cauchy, J. Barnard, M. G. Kanatzidis

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

Harvesting of waste heat may lead to macrocrack and/or microcrack damage accumulation in thermoelectrics. No studies in the open literature address the thermal fatigue of any thermoelectric material. This study characterizes the thermal fatigue behavior for two PbTe-based thermoelectric materials, n-type LAST (lead-antimony-silver-tellurium) and p-type LASTT (lead-antimony-silver- tellurium-tin). The mechanical properties (fracture strength, elastic moduli) were evaluated for up to 200 thermal fatigue cycles. In addition, the electrical and thermal transport properties were evaluated for n- and p-type specimens for thermal cycling. The elastic moduli were relatively insensitive to thermal fatigue treatment. The fracture strength, σ f, of the thermally fatigued LASTT specimens was in a band of from 25 to 40 MPa while σ f of the thermally fatigued LAST ranged from 15 to 38 MPa. The thermopower and electrical conductivity of LASTT samples showed small deviations from the low temperature trend near 600 K and the data repeated well after the first temperature cycle for all samples. For the n-type LAST samples, the electrical conductivity and thermopower showed larger deviations from the low temperature trend near 500 K with some samples requiring several temperature cycles before showing repeatability in the data, suggesting a possible secondary phase in the samples.

Original languageEnglish (US)
Pages (from-to)973-987
Number of pages15
JournalMaterials Chemistry and Physics
Volume134
Issue number2-3
DOIs
StatePublished - Jun 15 2012

Funding

The authors acknowledge funding from Strategic Environmental Research and Development Program provided by a subcontract through Pacific Northwest National Laboratory . The authors also acknowledge the Defense University Research Instrumentation Program (DURIP) Grant No. N00014-09-1-0785 , Office of Naval Research , which provided funding for the purchase of the Resonant Ultrasound Spectroscopy apparatus utilized in this research.

Keywords

  • Electrical conductivity
  • Fracture strength
  • Thermal fatigue
  • Thermoelectrics
  • Thermopower
  • Young's modulus

ASJC Scopus subject areas

  • General Materials Science
  • Condensed Matter Physics

Fingerprint

Dive into the research topics of 'Elastic modulus, biaxial fracture strength, electrical and thermal transport properties of thermally fatigued hot pressed LAST and LASTT thermoelectric materials'. Together they form a unique fingerprint.

Cite this