Rigid unit modes and the negative thermal expansion in ZrW2O8
- 1 May 1997
- journal article
- research article
- Published by Taylor & Francis Ltd in Phase Transitions
- Vol. 61 (1-4), 141-153
- https://doi.org/10.1080/01411599708223734
Abstract
ZrW2O8 has a negative coefficient of thermal expansion from 0.3 K to its decomposition temperature around 1050 K. The negative thermal expansion is isotropic and is not disrupted by the structural phase transition at 430 K. A complicated distribution in reciprocal space of Rigid Unit Mode (RUM) phonons has been found for ZrW2O8 using Lattice Dynamics. The RUMS are very low energy phonons which cause collective rotations of ZrO6 octahedra and WO4 tetrahedra within the crystal structure. These distortions enable ZrW2O8 to contract upon heating.Keywords
This publication has 12 references indexed in Scilit:
- Insights into zeolite behaviour from the rigid unit mode modelPhase Transitions, 1997
- Silicates and Soft ModesPublished by Springer Science and Business Media LLC ,1997
- Origin of the negative thermal expansion in andJournal of Physics: Condensed Matter, 1996
- Distortions of framework structuresPhase Transitions, 1996
- Negative Thermal Expansion from 0.3 to 1050 Kelvin in ZrW 2 O 8Science, 1996
- Ab initio studies of structural instabilities in magnesium silicate perovskitePhysics and Chemistry of Minerals, 1996
- Rigid unit modes in framework silicatesMineralogical Magazine, 1995
- Introduction to Lattice DynamicsPublished by Cambridge University Press (CUP) ,1993
- The lattice dynamics of forsteriteMineralogical Magazine, 1987
- The Infrared Spectra of MineralsPublished by Mineralogical Society ,1974