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 Corà, F. and Calleja, M. and Bruin, R. P. 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. DOI 10.1080/08927020500066684

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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
Uncontrolled Keywords:	2005 AREP 2005 P IA48
Subjects:	03 - Mineral Sciences
Divisions:	03 - Mineral Sciences
Journal or Publication Title:	Molecular Simulation
Volume:	31
Page Range:	pp. 367-377
Identification Number:	10.1080/08927020500066684
Depositing User:	Sarah Humbert
Date Deposited:	19 Oct 2011 16:35
Last Modified:	23 Jul 2013 09:58
URI:	http://eprints.esc.cam.ac.uk/id/eprint/1567

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