Elasticity of (K,Na)AlSi(3)O(8) hollandite from lattice dynamics calculations
International audience ; We compute the elastic constants tensor and the seismic properties of KAlSi(3)O(8) and K(0.8)Na(0.2)AlSi(3)O(8) up to the ferroelastic transition using density-functional theory and density-functional perturbation theory in the ABINIT implementation. We observe a softening of the tetragonal shear with pressure that precedes the ferroelastic transition. The Reuss shear moduli become negative at respectively 23 GPa and 13 GPa for the two compositions considered in here. The ferroelastic transition is associated with a strong decrease of the horizontal shear wave velociti... Mehr ...
| Verfasser: | |
|---|---|
| Dokumenttyp: | Artikel |
| Erscheinungsdatum: | 2010 |
| Verlag/Hrsg.: |
HAL CCSD
|
| Schlagwörter: | Hollandite / Elasticity / Subduction zone / Slabs / Alkalis / Density-functional theory / Phase transition / Lattice dynamics / Ferroelastic instability / [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
| Sprache: | Englisch |
| Permalink: | https://search.fid-benelux.de/Record/base-26735351 |
| Datenquelle: | BASE; Originalkatalog |
| Powered By: | BASE |
| Link(s) : | https://hal.archives-ouvertes.fr/hal-00683954 |
International audience ; We compute the elastic constants tensor and the seismic properties of KAlSi(3)O(8) and K(0.8)Na(0.2)AlSi(3)O(8) up to the ferroelastic transition using density-functional theory and density-functional perturbation theory in the ABINIT implementation. We observe a softening of the tetragonal shear with pressure that precedes the ferroelastic transition. The Reuss shear moduli become negative at respectively 23 GPa and 13 GPa for the two compositions considered in here. The ferroelastic transition is associated with a strong decrease of the horizontal shear wave velocities and a corresponding increase of the seismic anisotropy. The presence of Na enhances these features. (C) 2010 Elsevier B.V. All rights reserved.