Abstract
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.
Original language | English |
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Article number | 083722 |
Journal | Journal of Applied Physics |
Volume | 109 |
Issue number | 8 |
DOIs | |
State | Published - Apr 15 2011 |
Externally published | Yes |
Funding
This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52–07NA27344. The work at Brookhaven National Laboratory was supported by the U.S. Department of Energy, Basic Energy Sciences, Materials Sciences and Engineering Division, under Contract No. DE-AC02-98CH10886.
Funders | Funder number |
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U.S. Department of Energy | |
Basic Energy Sciences | |
Lawrence Livermore National Laboratory | |
Division of Materials Sciences and Engineering |