Electron-phonon coupling and thermal transport in the thermoelectric compound Mo3Sb7-xTex
Abstract
© 2015 American Physical Society.Phonon properties of Mo3Sb7-xTex (x=0,1.5,1.7), a
potential high-temperature thermoelectric material, have been studied with inelastic
neutron and x-ray scattering, and with first-principles simulations. The substitution
of Te for Sb leads to pronounced changes in the electronic structure, local bonding,
phonon density of states, dispersions, and phonon lifetimes. Alloying with tellurium
shifts the Fermi level upward, near the top of the valence band, resulting in a strong
suppression of electron-phonon screening and a large overall stiffening of interatomic
force constants. The suppression in electron-phonon coupling concomitantly increases
group velocities and suppresses phonon scattering rates, surpassing the effects of
alloy-disorder scattering and resulting in a surprising increased lattice thermal
conductivity in the alloy. We also identify that the local bonding environment changes
nonuniformly around different atoms, leading to variable perturbation strengths for
different optical phonon branches. Changes in phonon group velocities and phonon scattering
rates are quantified, highlighting the large effect of electron-phonon coupling in
this compound.
Type
Journal articlePermalink
https://hdl.handle.net/10161/11621Published Version (Please cite this version)
10.1103/PhysRevB.92.214301Publication Info
Bansal, D; Li, CW; Said, AH; Abernathy, DL; Yan, J; & Delaire, O (2015). Electron-phonon coupling and thermal transport in the thermoelectric compound Mo3Sb7-xTex.
Physical Review B - Condensed Matter and Materials Physics, 92(21). 10.1103/PhysRevB.92.214301. Retrieved from https://hdl.handle.net/10161/11621.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
Collections
More Info
Show full item recordScholars@Duke
Olivier Delaire
Associate Professor of Mechanical Engineering and Materials Science
The Delaire group investigates atomistic transport processes of energy and charge,
and thermodynamics in energy materials. We use a combined experimental and computational
approach to understand and control microscopic energy transport for the design of
next-generation materials, in particular for sustainable energy applications. Current
materials of interest include superionic conductors, photovoltaics, thermoelectrics,
ferroelectrics/multiferroics, and metal-insulator transitions. Our group

Articles written by Duke faculty are made available through the campus open access policy. For more information see: Duke Open Access Policy
Rights for Collection: Scholarly Articles
Works are deposited here by their authors, and represent their research and opinions, not that of Duke University. Some materials and descriptions may include offensive content. More info