THE PRESSURE-INDUCED FERROELASTIC PHASE-TRANSITION OF SIO2 STISHOVITE

Authors
Citation
Xcy. Lee et X. Gonze, THE PRESSURE-INDUCED FERROELASTIC PHASE-TRANSITION OF SIO2 STISHOVITE, Journal of physics. Condensed matter, 7(19), 1995, pp. 3693-3698
Citations number
32
Categorie Soggetti
Physics, Condensed Matter
ISSN journal
09538984
Volume
7
Issue
19
Year of publication
1995
Pages
3693 - 3698
Database
ISI
SICI code
0953-8984(1995)7:19<3693:TPFPOS>2.0.ZU;2-1
Abstract
Using a newly developed accurate ab initio technique, we study the sta bility and the lattice dynamics of SiO2 polymorph stishovite as a func tion of pressure. We observe a ferroelastic phase transition to CaCl2 structure at 64 GPa, driven by a mechanical instability associated wit h a vanishing shear modulus. Other lattice instabilities due to phonon anomalies are theoretically excluded along with a proposed softening of the B1g phonon mode.