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arXiv · 1106.1923

Lattice dynamical origin of peak thermoelectric performance in AgPbmSbTe2+m observed by inelastic neutron scattering

M. E. Manley·S. Shapiro·Q. Li·A. Llobet·M. E. Hagen
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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.

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M. E. Manley, S. Shapiro, Q. Li, A. Llobet, M. E. Hagen. 2011-06-09. Lattice dynamical origin of peak thermoelectric performance in AgPbmSbTe2+m observed by inelastic neutron scattering. https://doi.org/10.1063/1.3581155

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