Abstract
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 673 K 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 20 × 10-6 K-1 and 24 10-6 K-1, 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 (Ag0.86Pb19Sb 1.0Te20) exhibited a higher CTE value than that of the LAST material with a lower Ag content (Ag0.86Pb19Sb 1.0Te20). In addition, a peak in the temperature-dependent CTE was observed between room temperature and approximately 450 K for both the cast and hot-pressed LAST with the Ag0.86Pb19Sb 1.0Te20 composition, whereas the CTE of the Ag 0.86Pb19Sb1.0Te20 specimen increased monotonically with temperature.
| Original language | English |
|---|---|
| Pages (from-to) | 1439-1455 |
| Number of pages | 17 |
| Journal | Philosophical Magazine |
| Volume | 89 |
| Issue number | 18 |
| DOIs | |
| State | Published - Jun 2009 |
Funding
The authors acknowledge the financial assistance of the U.S. Department of Energy Grant DE-FC26-04NT42281 and Office of Naval Research MURI Grant number N000140310789. The research work at the High Temperature Materials Laboratory was sponsored by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Freedom CAR and Vehicle Technologies, as part of the High Temperature Materials Laboratory User Program, Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract number DE-AC05-00OR22725. One of the authors (F. Ren) would like to acknowledge the financial support from the Higher Education Research Experience program sponsored by the Oak Ridge National Laboratory during his tenure at the High Temperature Materials Laboratory.
| Funders | Funder number |
|---|---|
| Office of Freedom Car | |
| Office of Naval Research | N000140310789 |
| U.S. Department of Energy | DE-FC26-04NT42281 |
| Office of Energy Efficiency and Renewable Energy | |
| Oak Ridge National Laboratory | DE-AC05-00OR22725 |
Keywords
- Powder diffraction
- Semiconductor
- Thermal expansion
- Thermomechanical analysis