Unusual Low-Energy Phonon Dynamics in the Negative Thermal Expansion Compound ZrW2O8

An infrared study of the phonon spectra of ZrW2O8 as a function of temperature which includes the low energy (2-10 meV) region relevant to negative thermal expansion is reported and discussed in the context of specific heat and neutron density of states results. The prevalence of infrared active pho...

Full description

Saved in:
Bibliographic Details
Published in:arXiv.org 2004-10
Main Authors: Hancock, Jason N, Turpen, Chandra, Schlesinger, Zack, Kowach, Glen, Ramirez, Art
Format: Article
Language:English
Subjects:
Eigenvectors
Infrared spectroscopy
Lattice vibration
Phonons
Temperature dependence
Thermal expansion
Translational motion
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:An infrared study of the phonon spectra of ZrW2O8 as a function of temperature which includes the low energy (2-10 meV) region relevant to negative thermal expansion is reported and discussed in the context of specific heat and neutron density of states results. The prevalence of infrared active phonons at low energy and their observed temperature dependence are highly unusual and indicative of exotic low-energy lattice dynamics. Eigenvector calculations indicate a mixing of librational and translational motion within each low-frequency IR mode. The role of the underconstrained structure in establishing the nature of these modes, and the relationship between the IR spectra and the large negative thermal expansion in ZrW2O8 are discussed.
ISSN:2331-8422
DOI:10.48550/arxiv.0409533