Which phonons contribute most to negative thermal expansion in ScF3?
Open Access
- 1 April 2023
- journal article
- research article
- Published by AIP Publishing in APL Materials
- Vol. 11 (4)
Abstract
Using calculations of the phonon distribution in ScF3 across the whole of reciprocal space, we show that the important phonons for the negative thermal expansion in this material are those associated with the rigid unit modes (RUMs) and associated quasi-RUMs. We discuss the role of the bond-bending flexibility within the ScF6 octahedra, and how this enables other phonons to make an additional but ultimately much weaker contribution to negative thermal expansion. These results inform recent discussions on the role of correlated atomic motions in giving rise to negative thermal expansion in ScF3.Keywords
Funding Information
- Engineering and Physical Sciences Research Council (EP/P020232/1)
- National Natural Science Foundation of China (12174274)
This publication has 63 references indexed in Scilit:
- Two Decades of Negative Thermal Expansion Research: Where Do We Stand?Materials, 2012
- Pronounced Negative Thermal Expansion from a Simple Structure: Cubic ScF3Journal of the American Chemical Society, 2010
- Lattice dynamics and hydrostatic-pressure-induced phase transitions in ScF3Journal of Experimental and Theoretical Physics, 2002
- Geometrical Origin and Theory of Negative Thermal Expansion in Framework StructuresJournal of the American Ceramic Society, 1999
- The determination of rigid-unit modes as potential soft modes for displacive phase transitions in framework crystal structuresActa Crystallographica Section A Foundations of Crystallography, 1993
- The continuous melting transition of a three-dimensional crystal at a planar elastic instabilityJournal of Physics C: Solid State Physics, 1988
- Special points for Brillouin-zone integrationsPhysical Review B, 1976
- The thermal expansion of alkali halides at low temperatures - II. Sodium, rubidium and caesium halidesProceedings of the Royal Society of London. A. Mathematical and Physical Sciences, 1973
- The thermal expansion of alkali halides at low temperaturesProceedings of the Royal Society of London. A. Mathematical and Physical Sciences, 1965
- Theorie des festen Zustandes einatomiger ElementeAnnalen der Physik, 1912