Hopping Time Scales and the Phonon-Liquid Electron-Crystal Picture in Thermoelectric Copper Selenide. / Voneshen, David; Walker, Helen; Refson, Keith; Goff, Jonathan.

In: Physical Review Letters, Vol. 118, No. 14, 145901, 05.04.2017, p. 1-5.

Research output: Contribution to journalArticle

Published

Documents

Abstract

The suppression of transverse phonons by liquidlike diffusion in superionic conductors has been proposed as a means to dramatically reduce thermal conductivity in thermoelectric materials [H. Lui et al. Nat. Mater. 11, 422 (2012)]. We have measured the ion transport and lattice dynamics in the original phonon-liquid electron-crystal Cu2Se using neutron spectroscopy. We show that hopping time scales are too slow to significantly affect lattice vibrations and that the transverse phonons persist at all temperatures. Substantial changes to the phonon spectrum occur well below the transition to the superionic phase, and the ultralow thermal conductivity is instead attributed to anharmonicity.
Original languageEnglish
Article number145901
Pages (from-to)1-5
Number of pages5
JournalPhysical Review Letters
Volume118
Issue number14
DOIs
Publication statusPublished - 5 Apr 2017
This open access research output is licenced under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

ID: 27947774