Lattice dynamical origin of peak thermoelectric performance in AgPbmSbTe2+m observed by inelastic neutron scattering
| Autor: | Qiang Li, Stephen M. Shapiro, A. Llobet, M. E. Hagen, Michael Manley |
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| Rok vydání: | 2011 |
| Předmět: |
Condensed Matter - Materials Science
Materials science Condensed matter physics Scattering Phonon Neutron diffraction Fermi level Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences General Physics and Astronomy Thermoelectric materials Inelastic neutron scattering symbols.namesake Condensed Matter::Superconductivity Seebeck coefficient Thermoelectric effect symbols |
| Zdroj: | Journal of Applied Physics. 109:083722 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.3581155 |
| Popis: | Phonon densities of states (DOS) for the high performing thermoelectric material, AgPbmSbTe2+m (LAST-m, m = 16, 18, and 20), were extracted from time-of-flight inelastic neutron scattering measurements. The phonon DOS of LAST-18 differs remarkably from LAST-16 and LAST-20 by exhibiting a dramatic broadening of its acoustic modes that increases on heating. This broadening coincides with a minimum in the thermal conductivity, a maximum in the electrical conductivity and Seebeck coefficient, and a related peak in thermoelectric performance. We argue that the anomalous broadening originates with scattering enhanced by modifications to Te-Ag(Sb) bonds caused by their resonant electronic states falling near the Fermi energy for m = 18. Comment: 13 pages, 2 figures |
| Databáze: | OpenAIRE |
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