Electron-phonon coupling and thermal transport in the thermoelectric compound Mo3Sb7-xTex

Bansal, D

Li, CW

Said, AH

Abernathy, DL

Yan, J

Delaire, O

2016-02-22T19:48:40Z

2015-12-07

© 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.

1550-235X

1098-0121

https://hdl.handle.net/10161/11621

American Physical Society (APS)

Physical Review B - Condensed Matter and Materials Physics

10.1103/PhysRevB.92.214301

Electron-phonon coupling and thermal transport in the thermoelectric compound Mo3Sb7-xTex

Journal article

Delaire, O|0000-0003-1230-2834

21

Duke

Mechanical Engineering and Materials Science

Physics

Pratt School of Engineering

Trinity College of Arts & Sciences

Published

92