Temperature-dependent thermal expansion of cast and hot-pressed LAST (Pb-Sb-Ag-Te) thermoelectric materials

Journal Article · Thu Jan 01 04:00:00 EST 2009 · Philosophical Magazine

DOI:https://doi.org/10.1080/14786430903002376· OSTI ID:1048761

Ren, Fei ^[1]; Hall, Bradley D. ^[2]; Case, Eldon D ^[2]; Timm, Edward J ^[2]; Trejo, Rosa M ^[1]; Meisner, Roberta Ann ^[1]; Lara-Curzio, Edgar ^[1]

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1. ORNL
2. Michigan State University, East Lansing

The thermal expansion for two compositions of cast and hot-pressed LAST (Pb Sb Ag Te) n-type thermoelectric materials has been measured between room temperature and 673K via thermomechanical analysis (TMA). In addition, using high-temperature X-ray diffraction (HT-XRD), the thermal expansion for both cast and hot-pressed LAST materials was determined from the temperature-dependent lattice parameters measured between room temperature and 623 K. The TMA and HT-XRD determined values of the coefficient of thermal expansion (CTE) for the LAST compositions ranged between 20106K1 and 24106K1, which is comparable to the CTE values for other thermoelectric materials including PbTe and Bi2Te3. The CTE of the LAST specimens with a higher Ag content (Ag0.86Pb19Sb1.0Te20) exhibited a higher CTE value than that of the LAST material with a lower Ag content (Ag0.43Pb18Sb1.2Te20). In addition, a peak in the temperature-dependent CTE was observed between room temperature and approximately 450K for both the cast and hot-pressed LAST with the Ag0.86Pb19Sb1.0Te20 composition, whereas the CTE of the Ag0.43Pb18Sb1.2Te20 specimen increased monotonically with temperature.

• Research Organization: Oak Ridge National Laboratory (ORNL); High Temperature Materials Laboratory
• Sponsoring Organization: EE USDOE - Office of Energy Efficiency and Renewable Energy (EE)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1048761
• Journal Information: Philosophical Magazine, Journal Name: Philosophical Magazine Journal Issue: 18 Vol. 89; ISSN 1478-6435
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
LATTICE PARAMETERS
THERMAL EXPANSION
THERMOELECTRIC MATERIALS
X-RAY DIFFRACTION