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RESEARCH PRODUCT
Charged oxygen interstitials in corundum: first principles simulations
Sergei PiskunovEugene A. KotominYuri F. ZhukovskiiAlexander PlatonenkoDenis Gryaznovsubject
ChemistryAb initioCorundum02 engineering and technologyengineering.material010402 general chemistry021001 nanoscience & nanotechnologyCondensed Matter Physics7. Clean energy01 natural sciences0104 chemical sciencesIonCondensed Matter::Materials ScienceOctahedronAtomPhysics::Atomic and Molecular ClustersengineeringSupercell (crystal)DumbbellAtomic physics10. No inequality0210 nano-technologyElectronic densitydescription
Combining supercell models and hybrid B3PW exchange-correlation functionals, ab initio simulations on quasi-stable configurations of interstitial ions in α-Al2O3 (corundum) crystals and possible migration trajectories have been modelled. We have studied crystalline distortion around migrating including interatomic distances and the effective atomic charges, as well as redistributions of the electronic density. Unlike neutral interstitial atom Oi studied by us previously, migrating ion does not form dumbbells with the nearest regular oxygen ions, due to the strong Coulomb interaction with the nearest cations as well as stronger repulsion between and adjacent regular ions. We have also estimated the energy barrier for migration between the nearest quasistable configurations of interstitial ion. One of these configurations is an octahedron formed by six nearest anions in the centre of which ion is located, unlike a neutral Oi atom which prefers to migrate directly towards one of adjacent anions with the dumbbell formation. As the result, the barrier for ion migration in corundum has been found to be by ∼70% smaller than that of Oi atom. (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2016-08-09 | physica status solidi c |