Toward a mechanism of rattler coupling in the β-pyrochlores AOs2O6 (A = K, Rb, Cs)

Simple item page
dc.contributor.authorShoko, Een_AU
dc.contributor.authorPeterson, VKen_AU
dc.contributor.authorKearley, GJen_AU
dc.date.accessioned2016-10-26T23:23:55Zen_AU
dc.date.available2016-10-26T23:23:55Zen_AU
dc.date.issued2014-03-03en_AU
dc.date.statistics2016-10-27en_AU
dc.description.abstractWe have applied ab initio molecular dynamics simulations to study metal–metal coupling on the alkali-metal sublattice in the β-pyrochlore osmates, AOs2O6 (A = K, Rb, Cs) at 300 K. We find that the dynamics of the alkali-metal atoms (rattlers) exhibit stronger rattler–rattler correlations than rattler–cage correlations, and that, at 300 K, this correlation is strongest for Cs. We show that the rattler–rattler correlations control the dominant dynamics in the rattling of these atoms. We provide preliminary evidence that the rattler correlated motion occurs primarily through two somewhat distinct vibrational modes: a high-energy mode (peak A) couples the rattlers to each other and a low-energy mode (peak B) couples the rattlers to the cage modes. Rattler–rattler correlated motion through the high-energy mode provides insight into the trend in spectral broadening from Cs to K. The spectral broadening is inversely proportional to the strength of the dynamical correlations on the alkali-metal sublattice which in turn depend on the atomic size of the rattler, decreasing from Cs to K. Thus, the broadest spectrum exhibited by the K is partly a consequence of the small size of this rattler which permits a greater range of motions involving combinations of both correlated and anti-correlated dynamics. We emphasize that the identification of the somewhat distinct roles of the high-energy (peak A) and low-energy (peak B) modes in rattler coupling reported in this work is a significant step toward a complete fundamental mechanism of rattler dynamical coupling in these osmates. We believe that such a mechanism will have profound implications for a broad class of cage compounds, including clathrates and skutterudites.© 2014, Springer Science+Business Media New York.en_AU
dc.identifier.citationShoko, E., Peterson, V., & Kearley, G. (2014). Toward a mechanism of rattler coupling in the β-pyrochlores AOs2O6 (A = K, Rb, Cs). Journal of Materials Science, 49(15), 5468-5480. doi:10.1007/s10853-014-8260-xen_AU
dc.identifier.govdoc7468en_AU
dc.identifier.issn1573-4803en_AU
dc.identifier.issue15en_AU
dc.identifier.journaltitleJournal of Materials Scienceen_AU
dc.identifier.pagination5468-5480en_AU
dc.identifier.urihttp://dx.doi.org/10.1007/s10853-014-8260-xen_AU
dc.identifier.urihttp://apo.ansto.gov.au/dspace/handle/10238/7917en_AU
dc.identifier.volume49en_AU
dc.language.isoenen_AU
dc.publisherSpringer Linken_AU
dc.subjectMolecular dynamics methoden_AU
dc.subjectAcid neutralizing capacityen_AU
dc.subjectAlkali metalsen_AU
dc.subjectPyrochloreen_AU
dc.subjectClathratesen_AU
dc.titleToward a mechanism of rattler coupling in the β-pyrochlores AOs2O6 (A = K, Rb, Cs)en_AU
dc.typeJournal Articleen_AU
Files
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Journal Articles