Ab initio simulations on migration paths of interstitial oxygen in corundum

Zhukovskii, Yuri F.; Platonenko, Alexander; Piskunov, Sergei

doi:10.1016/j.nimb.2015.08.087

Cited by 21 publications

(27 citation statements)

References 32 publications

(49 reference statements)

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“…The estimated lowest energy barrier for migration of neutral Oi is ~1.3 eV [19]. In partly covalent corundum the regular oxygen atomic charge is -0.9 e [41].…”

Section: Discussionmentioning

confidence: 99%

“…Ab initio calculations of Oi interstitials in different charge states have been performed so far for a number of binary metal oxides. It was predicted that interstitial oxygen atoms could form peroxide-like split interstitials (dumbbells) with the regular oxygen atoms in binary metal oxides MgO [17], α-Al2O3 [18,19], ZnO (wurtzite) [20], SnO2 [21], TiO2 (anatase) [22], CeO2 [23,24], monoclinic HfO2 [25] as well as in complex oxide 12CaO•7Al2O3 [26]. In most cases, the O-O distance is about 1.4-1.5 Å (table 1).…”

Section: Introductionmentioning

confidence: 99%

“…Previously, we have performed hybrid DFT-LCAO calculations on the atomic and electronic structure for a neutral Oi atoms in -Al2O3 using the so-called site symmetry approach [31]. For corundum, we have simulated migration trajectories of neutral Oi atoms [19] as well as atomic structures of both charged single Oiinterstitials and dumbbells [27].…”

Section: Introductionmentioning

confidence: 99%

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Ab initio simulations on charged interstitial oxygen migration in corundum

Platonenko

Gryaznov

Zhukovskii

2018

Nuclear Instruments and Methods in Physics Research Section B:

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We have calculated possible migration trajectories for single-charged interstitial Oianion using large-scale hybrid DFT-LCAO calculations on 221 supercells of defective -Al2O3 crystals when applying CRYSTAL14 computer code. For interstitial migration of anion, the energy barrier being calculated ~0.8-1.0 eV. Energetically most favorable configuration for charged Oianion is formation of loose "dumbbell" (split interstitial) with regular Oreg ion. This is considerably smaller than that for neutral interstitial atoms and is in agreement with experimental data.

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“…The estimated lowest energy barrier for migration of neutral Oi is ~1.3 eV [19]. In partly covalent corundum the regular oxygen atomic charge is -0.9 e [41].…”

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Ab initio simulations on charged interstitial oxygen migration in corundum

Platonenko

Gryaznov

Zhukovskii

2018

Nuclear Instruments and Methods in Physics Research Section B:

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“…The latter theoretical study was the first attempt of hyperfine coupling constants calculations using the first-principles methods for MgAl 2 O 4 spinel, and to the best of our knowledge, other oxides. Notice that the first-principles calculations, see 40 – 42 , 54 , were performed with the hybrid exchange-correlation functionals.…”

Section: Introductionmentioning

confidence: 99%

“…According to theoretical calculations, single oxygen interstitials in the neutral charge state in MgO and Al 2 O 3 are unstable with respect to transformation into a dumbbell configuration, their atomic charges and diffusion in MgO and Al 2 O 3 crystals have been theoretically analyzed [38][39][40][41] . Diffusion of charged oxygen interstitial defects was also discussed in Ref.…”

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confidence: 99%

Atomic, electronic and magnetic structure of an oxygen interstitial in neutron-irradiated Al2O3 single crystals

Seeman

Lushchik

Shablonin

et al. 2020

Sci Rep

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A single radiation-induced superoxide ion $$O_{2}^{ - }$$ O 2 - has been observed for the first time in metal oxides. This structural defect has been revealed in fast-neutron-irradiated (6.9×1018n/cm2) corundum (α-Al2O3) single crystals using the EPR method. Based on the angular dependence of the EPR lines at the magnetic field rotation in different planes and the determined g tensor components, it is shown that this hole-type $$O_{2}^{ - }$$ O 2 - center (i) incorporates one regular and one interstitial oxygen atoms being stabilized by a trapped hole (S = 1/2), (ii) occupies one oxygen site in the (0001) plane being oriented along the a axis, and (iii) does not contain any other imperfection/defect in its immediate vicinity. The thermal stepwise annealing (observed via the EPR signal and corresponding optical absorption bands) of the $$O_{2}^{ - }$$ O 2 - centers, caused by their destruction with release of a mobile ion (tentatively the oxygen ion with the formal charge −1), occurs at 500–750 K, simultaneously with the partial decay of single F-type centers (mostly with the EPR-active F+ centers). The obtained experimental results are in line with the superoxide defect configurations obtained via density functional theory (DFT) calculations employing the hybrid B3PW exchange-correlation functional. In particular, the DFT calculations confirm the $$O_{2}^{ - }$$ O 2 - center spin S = 1/2, its orientation along the a axis. The $$O_{2}^{ - }$$ O 2 - center is characterized by a short O–O bond length of 1.34 Å and different atomic charges and magnetic moments of the two oxygens. We emphasize the important role of atomic charges and magnetic moments analysis in order to identify the ground state configuration.

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The Two Types of Oxygen Interstitials in Neutron‐Irradiated Corundum Single Crystals: Joint Experimental and Theoretical Study

Lushchik

Kuzovkov

Kudryavtseva

et al. 2021

Physica Status Solidi (b)

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Corundum (α‐Al2O3) is a technologically important material and, in particular, widely used in optical applications such as luminescent radiation dosimeters, cryogenic scintillators, and is being considered as a promising candidate for windows in future fusion reactors. Its optical and mechanical properties are controlled by the presence of radiation‐induced (in particular, by fast neutrons) defects. Herein, the thermal stability and recombination kinetics of primary anion Frenkel defects—the F and F + electronic centers and oxygen interstitials—in fast‐neutron‐irradiated α‐Al2O3 single crystals are analyzed. Theory is developed considering the formation of both neutral and charged oxygen Frenkel defect pairs; defect migration, interaction and recombination. Based on ab initio calculations and new theoretical kinetics analysis, for the first time, a coexistence is demonstrated, in comparable concentrations, of two interstitial types—neutral O atoms and negatively charged O− ions (with attributed optical absorption band maxima at 6.5 eV and 5.6 eV, respectively); and their diffusion parameters, necessary for the prediction of secondary defect‐induced reactions and defect/material thermal stability, are obtained.

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Ab initio simulations on migration paths of interstitial oxygen in corundum

Cited by 21 publications

References 32 publications

Ab initio simulations on charged interstitial oxygen migration in corundum

Ab initio simulations on charged interstitial oxygen migration in corundum

Atomic, electronic and magnetic structure of an oxygen interstitial in neutron-irradiated Al2O3 single crystals

The Two Types of Oxygen Interstitials in Neutron‐Irradiated Corundum Single Crystals: Joint Experimental and Theoretical Study

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