Structural and magnetic phase transitions in simple oxides using hybrid functionals

Alfredsson, M. and Brodholt, J.P. and Wilson, P.B. and Price, G.D. and Cora, F. and Calleja, A. and Bruin, R. and Blanshard, L.J. and Tyer, R.P. (2005) Structural and magnetic phase transitions in simple oxides using hybrid functionals. Molecular Simulation, 31 (5). pp. 367-377. ISSN 0892-7022. (The full text of this publication is not available from this repository)

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Official URL
http://dx.doi.org/10.1080/08927020500066684

Abstract

We present the structural as well as elastic properties of the alkaline earth oxides and FeO, calculated using hybrid exchange functionals within DFT. We show that by empirically fitting the amount of Fock-exchange in the hybrid functionals, we can accurately reproduce the pressure-induced phase transitions for MgO, CaO, SrO and BaO. For FeO the hybrid functionals predict an insulator <-> metal transition at ca. 150 GPa, associated with an i-B8 <-> B8 structural phase transition. The structural phase transition is accompanied by a spin transition from a high- to low-spin electron configuration on the Fe2+ ions. Hence, FeO undergoes a magnetic phase transition from an anti-ferromagnetic to non-magnetic structure. We also find that as the ionicity of the polymorphs increases a higher fraction of Fock-exchange is required to reproduce the structural volumes reported from experiments.

Item Type: Article
Additional information: ISI Document Delivery No.: 937ZS Times Cited: 3 Cited Reference Count: 61
Uncontrolled keywords: alkaline earth oxide FeO DFT GGA LDA hybrid functional ALKALINE-EARTH OXIDES GENERALIZED GRADIENT APPROXIMATION HIGH-PRESSURE HARTREE-FOCK CORRELATION-ENERGY BULK PROPERTIES DENSITY MGO EXCHANGE FEO
Subjects: Q Science
Divisions: Faculties > Science Technology and Medical Studies > School of Physical Sciences > Functional Materials Group
Depositing User: Maria Alfredsson
Date Deposited: 02 Sep 2008 20:33
Last Modified: 14 Jan 2010 14:17
Resource URI: http://kar.kent.ac.uk/id/eprint/4759 (The current URI for this page, for reference purposes)
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