Ferroelastic nature of high pressure phase transition in MgF2

Zivkovic, Aleksander ORCID: https://orcid.org/0000-0003-1347-6203 and Lukacevic, Igor 2016. Ferroelastic nature of high pressure phase transition in MgF2. Journal of Alloys and Compounds 682 , pp. 839-843. 10.1016/j.jallcom.2016.05.059

Full text not available from this repository.

Abstract

Using quantum theoretical simulations based on density functional and density functional perturbation theory we illuminate the nature of the phase transition occurring in magnesium fluoride (MgF2) at high pressure. At atmospheric pressure it is stable in the rutile structure. It was predicted by theory and later confirmed by experiments that a phonon soft mode driven phase transition transforms MgF2 to a CaCl2-type structure. The phase transition was connected with an optic phonon mode B1g. By simulating the behavior of phonons at and near the Γ point we prove that a lattice dynamical instability originates in an unstable acoustic phonon mode. The calculation of the elastic constants shows that the phase transition is a proper ferroelastic phase transition occurring under a homogenous deformation of the crystal lattice. These results further illustrate the behavior of fluoride materials under extreme conditions, such as pressure.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Chemistry
Publisher:	Elsevier
ISSN:	0925-8388
Date of Acceptance:	7 May 2016
Last Modified:	26 Oct 2022 08:51
URI:	https://orca.cardiff.ac.uk/id/eprint/128491

Citation Data

Cited 3 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item