Journal articles: 'Oxygen vacancy'

1

Shyichuk, A., and E. Zych. "Oxygen Vacancy, Oxygen Vacancy–Vacancy Pairs, and Frenkel Defects in Cubic Lutetium Oxide." Journal of Physical Chemistry C 124, no. 28 (June 12, 2020): 14945–62. http://dx.doi.org/10.1021/acs.jpcc.0c00974.

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CHEN, WEN-KAI, BAO-ZHEN SUN, XIA WANG, and CHUN-HAI LU. "THE ROLE OF SURFACE OXYGEN VACANCY IN N2O DECOMPOSITION ON Cu2O(111) SURFACE: A DFT STUDY." Journal of Theoretical and Computational Chemistry 07, no. 02 (April 2008): 263–76. http://dx.doi.org/10.1142/s0219633608003733.

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The role of a surface oxygen vacancy in the N 2 O dissociation over a Cu 2 O surface was studied using density functional theory — generalized gradient approximation periodic calculations. To perform this study, surface slab model — [Formula: see text] surface cell was used. The results indicated that N 2 O adsorption properties were associated with the surface oxygen vacancies. The presence of a surface oxygen vacancy, prepared by removing one O SUF atom from [Formula: see text] supercell, makes the N 2 O decomposition possible, which was believed to occur at a oxygen vacancy site. The N 2 O decomposition at the surface oxygen vacant site depends on whether the molecule is adsorbed with the O - or N -end on a vacancy. For the first case, the reaction proceeds spontaneously, which leads to an ejection of N 2 from the surface and the rest of the oxygen atoms occupying the vacancy. In the second case, even though there is an elongation of both N – N and N – O bonds, the dissociation is unfeasible due to very small adsorption energy and high activation energy. The role of the defective surface with surface oxygen vacancy is to provide electrons to the adsorbed molecule.

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3

Chen, X. Y., L. H. Zhang, Y. P. Wang, S. Q. Wu, Z. F. Hou, and Z. Z. Zhu. "First-Principles Studies on the Formation of Oxygen Vacancies in Li₂CoSiO₄." Journal of The Electrochemical Society 168, no. 11 (November 1, 2021): 110527. http://dx.doi.org/10.1149/1945-7111/ac35ce.

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The existence of oxygen vacancy has a significant effect on the structural and electronic properties of Li2CoSiO4. Herein, the formation energy of an oxygen vacancy (V O) in Li2CoSiO4 in different oxidation environments is calculated by using a first-principles method. The increased temperature, decreased oxygen partial pressure, and the increased charge state of O vacancy reduce the formation energy of the oxygen vacancy. The presence of V O is accompanied by a distinct redistribution of the electronic charge densities only around the Co and Si ions next to the O-vacancy site, which shows a very local influence on the host material arising from V O. Furthermore, the existence of vacancy defects ( V L i 1 , V L i 2 , V C o and V S i ) in the vicinity of the O vacancy are found to be beneficial to the formation of the O vacancy. The substitutional defects, M n C o and N i C o , near the O vacancy are found to increase the formation energy of the oxygen vacancy, however, F e C o decreases the formation energy of the O vacancy.

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4

Mastrikov, Yuri A., Denis Gryaznov, Guntars Zvejnieks, Maksim N. Sokolov, Māra Putniņa, and Eugene A. Kotomin. "Sr Doping and Oxygen Vacancy Formation in La1−xSrxScO3−δ Solid Solutions: Computational Modelling." Crystals 12, no. 9 (September 14, 2022): 1300. http://dx.doi.org/10.3390/cryst12091300.

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Sr-doped lanthanum scandate La1−xSrxScO3−δ (LSS) is a promising perovskite-type material for electrochemical applications such as proton conductors. Oxygen vacancy is a common defect in ABO3-type perovskites. It controls ion transport as well as proton uptake. The energetic, structural, and electronic properties of oxygen vacancy in LSS are studied deploying the DFT method with meta-GGA functional. The vacancy formation energies in LSS were calculated for various Sr concentrations. Unlike other perovskites, in this material, the electrons are trapped at the oxygen vacancy site (the F-type centres, common in ionic oxides like MgO and Al2O3) rather than localised on the nearest to the vacancy B-cations. The process of oxygen vacancy formation is considered relative to Sr concentration x and oxygen nonstoichiometry factor δ. Three primary regimes are discussed: (I) localized at the vacancy electrons, x/δ < 2, (II) electron charge balanced system, x/δ = 2, and (III) delocalized electron holes, x/δ > 2. For x/δ ≥ 2 oxygen vacancy formation energy reaches the saturation level of ~3.5 eV, which is potentially beneficial for the proton uptake.

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5

Huang, Yanmei, Yu Yu, Yifu Yu, and Bin Zhang. "Oxygen Vacancy Engineering in Photocatalysis." Solar RRL 4, no. 8 (March 31, 2020): 2000037. http://dx.doi.org/10.1002/solr.202000037.

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6

Peng, Yin-Hui, Chang-Chun He, Yu-Jun Zhao, and Xiao-Bao Yang. "Multi-peak emission of In₂O₃ induced by oxygen vacancy aggregation." Journal of Applied Physics 133, no. 7 (February 21, 2023): 075702. http://dx.doi.org/10.1063/5.0135162.

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Oxygen vacancy is crucial to the optical properties in In[Formula: see text]O[Formula: see text], however, the single oxygen vacancy model fails to explain the observed multi-peak emission in the experiment. Herein, we have theoretically investigated the diversity of oxygen vacancy distribution, revealing the relationship between the defect configurations and the optical properties. Combining the first-principles calculations and bayesian regularized artificial neural networks, we demonstrate that the structural stability can be remarkably enhanced by multi-oxygen vacancy aggregation, which will evolve with the defect concentration and temperature. Notably, our results indicate that the single oxygen vacancy will induce the emission peaks centered at 1.35 eV, while multi-peak emission near 2.35 eV will be attributed to the distribution of aggregated double oxygen vacancies. Our findings provide a comprehensive understanding of multi-peak emission observed in In[Formula: see text]O[Formula: see text], and the rules of the vacancy distribution may be extended for other metal oxides to modulate the optical properties in practice.

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7

Li, Tong, Qi Wang, and Zhou Wang. "Oxygen Vacancy Injection on (111) CeO2 Nanocrystal Facets for Efficient H2O2 Detection." Biosensors 12, no. 8 (August 3, 2022): 592. http://dx.doi.org/10.3390/bios12080592.

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Facet and defect engineering have achieved great success in improving the catalytic performance of CeO2, but the inconsistent reports on the synergistic effect of facet and oxygen vacancy and the lack of investigation on the heavily doped oxygen vacancy keeps it an attractive subject. Inspired by this, CeO2 nanocrystals with selectively exposed crystalline facets (octahedron, cube, sphere, rod) and abundant oxygen vacancies have been synthesized to investigate the synergistic effect of facet and heavily doped oxygen vacancy. The contrasting electrochemical behavior displayed by diverse reduced CeO2 nanocrystals verifies that oxygen vacancy acts distinctly on different facets. The thermodynamically most stable CeO2 octahedron enclosed by heavily doped (111) facets surprisingly exhibited the optimum non-enzymatic H2O2 sensing performance, with a high sensitivity (128.83 µA mM−1 cm−2), a broad linear range (20 µM~13.61 mM), and a low detection limit (1.63 µM). Meanwhile, the sensor presented satisfying selectivity, repeatability, stability, as well as its feasibility in medical disinfectants. Furthermore, the synergistic effect of facet and oxygen vacancy was clarified by the inclined distribution states of oxygen vacancy and the electronic transmission property. This work enlightens prospective research on the synergistic effect of alternative crystal surface engineering strategies.

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8

Chen, Dong, Fei Gao, Hui-Qiu Deng, Bo Liu, Wang-Yu Hu, and Xin Sun. "Migration of defect clusters and xenon-vacancy clusters in uranium dioxide." International Journal of Modern Physics B 28, no. 18 (June 3, 2014): 1450120. http://dx.doi.org/10.1142/s0217979214501203.

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The possible transition states, minimum energy paths (MEPs) and migration mechanisms of defect clusters and xenon-vacancy defect clusters in uranium dioxide ( UO 2) have been investigated using the dimer and the nudged elastic-band (NEB) methods. The nearby O atom can easily hop into the oxygen vacancy position by overcoming a small energy barrier, which is much lower than that for the migration of a uranium vacancy. A simulation for a vacancy cluster consisting of two oxygen vacancies reveals that the energy barrier of the divacancy migration tends to decrease with increasing the separation distance of divacancy. For an oxygen interstitial, the migration barrier for the hopping mechanism is almost three times larger than that for the exchange mechanism. Xe moving between two interstitial sites is unlikely a dominant migration mechanism considering the higher energy barrier. A net migration process of a Xe-vacancy pair containing an oxygen vacancy and a xenon interstitial is identified by the NEB method. We expect the oxygen vacancy-assisted migration mechanism to possibly lead to a long distance migration of the Xe interstitials in UO 2. The migration of defect clusters involving Xe substitution indicates that Xe atom migrating away from the uranium vacancy site is difficult.

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9

Das, Tridip, Jason D. Nicholas, and Yue Qi. "Polaron size and shape effects on oxygen vacancy interactions in lanthanum strontium ferrite." Journal of Materials Chemistry A 5, no. 47 (2017): 25031–43. http://dx.doi.org/10.1039/c7ta06948k.

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10

Yuhara, S., Yorinobu Takigawa, Tokuteru Uesugi, and Kenji Higashi. "Effect of Co-Doping Cation on Phase Stability of Zirconia Bioceramics in Hot Water." Advanced Materials Research 26-28 (October 2007): 773–76. http://dx.doi.org/10.4028/www.scientific.net/amr.26-28.773.

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Phase stability of cation co-doped zirconia ceramics is examined. As the result, in contrast to the result in small amount of single cation doped zirconia, phase stability of co-doped zirconia ceramics can not be simply explained from ionic radius and valency of dopant or from the change in axis ratio. We focus on oxygen vacancy concentration and binding energy between oxygen vacancy and doped cation. By estimating phase stability from these factors, it is found that concentration of oxygen vacancy and the binding energy between the dopant and the oxygen vacancy are important factors for understanding the phase stability of zirconia ceramics.

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11

Chen, Lanli, Yuanyuan Cui, Siqi Shi, Bin Liu, Hongjie Luo, and Yanfeng Gao. "First-principles study of the effect of oxygen vacancy and strain on the phase transition temperature of VO2." RSC Advances 6, no. 90 (2016): 86872–79. http://dx.doi.org/10.1039/c6ra19121e.

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12

Ma, Qiao Yun, Gui Feng Chen, Hui Zhang, Jing Jing Xue, Peng Su, Qiu Yan Hao, and Cai Chi Liu. "Progress in Study of Oxygen-Related Defects in Electron Irradiated CZ-Si." Advanced Materials Research 427 (January 2012): 115–18. http://dx.doi.org/10.4028/www.scientific.net/amr.427.115.

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Electron irradiation on silicon results in the creation of vacancy (V) and silicon self-interstitial (I).Vacancy tends to integrate with oxygen and forms the complexes of vacancy and oxygen (VmOn)such as VO, VO2, and VO3. These complexes of vacancy and oxygen in silicon have been the subject of extended investigations by standard methods such as infrared absorption. In infrared spectrum, the different VmOnhas the corresponding peak. Irradiation induced defects as the core of oxygen precipitate can accelerate the oxygen precipitation. Oxygen precipitation plays an important role in the internal gettering (IG). In electron irradiated silicon, annealing at 300700 °C leads to the formation of two types of electrically active centers that are shallow thermal acceptors (TAs) and the well-known thermal donors (TDs). In this paper, the generation conditions, the infrared peaks of VmOn, the types of oxygen precipitation induced defects, the characters of TAs and TDs are studied.

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13

Yang, Chao, Enwei Sun, Zhen Liu, Xingru Zhang, Xudong Qi, and Wenwu Cao. "Phase-field simulation on the interaction of oxygen vacancies with charged and neutral domain walls in hexagonal YMnO₃." Journal of Physics: Condensed Matter 34, no. 16 (February 21, 2022): 165401. http://dx.doi.org/10.1088/1361-648x/ac50d8.

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Abstract A three-dimensional model of the interaction between the charged or neutral domain walls and oxygen vacancies in the hexagonal manganite YMnO3 was proposed, and simulated using Landau–Ginzburg–Devonshire (LGD) theory, dynamic diffusion equation and Maxwell’s equation. The calculation proves that stiffness anisotropic factors can adjust the domain wall state and ultimately affect the distribution of oxygen vacancies. The head-to-head domain wall corresponds to low oxygen vacancy density, and the tail-to-tail domain wall corresponds to high oxygen vacancy density. The electrostatic field generated by the bound charge is the key factor leading to the change of oxygen vacancy distribution. Finally, e-index law N d = ae b*dP/dz can fit the relationship between the oxygen vacancy concentration and the polarization gradient along z direction. Our theory provides a new way to modulate the distribution of oxygen vacancies through domain wall morphology in hexagonal YMnO3.

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14

Li, Yongjin, Lu Yao, Zhaoyi Yin, Zhiyuan Cheng, Shenghong Yang, and Yueli Zhang. "Defect-induced abnormal enhanced upconversion luminescence in BiOBr:Yb3+/Er3+ ultrathin nanosheets and its influence on visible-NIR light photocatalysis." Inorganic Chemistry Frontiers 7, no. 2 (2020): 519–28. http://dx.doi.org/10.1039/c9qi01275c.

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15

Wang, Qing Bo, and Cui Zhou. "First-Principles Study the Effects of Single Zinc or Oxygen Vacancy on the Electronic and Optical Properties of V-Doped ZnO." Advanced Materials Research 393-395 (November 2011): 114–18. http://dx.doi.org/10.4028/www.scientific.net/amr.393-395.114.

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We researched the effect of single zinc or oxygen vacancy on the electronic and optical properties of V-doped ZnO. All calculations were performed by CASTEP in materials studio software. Total energy showed that an oxygen vacancy inclined to stay at the position far from vanadium (V). A zinc vacancy preferred to localize at the position near V. The V atom substitution for zinc (Zn) introduced spin-polarization at Fermi-level. Vanadium made electronic density of states moved to lower energy. Vanadium doping broadened the density of states peaks of pure ZnO. An oxygen or Zn vacancy also broadened the density of states peaks of V-doped ZnO. The V doping introduced optical properties at lower energy. An oxygen vacancy improved lower-energy optical properties much. Our calculation provided a reference for the preparation and applications of V-doped ZnO in optical fields.

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16

Weng, Zhen Zhen, Zhi Gao Huang, and Wen Xiong Lin. "First-Principles Study on Co-Doped ZnO with Oxygen Vacancy." Advanced Materials Research 154-155 (October 2010): 124–29. http://dx.doi.org/10.4028/www.scientific.net/amr.154-155.124.

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The interatomic exchange interactions and the electronic structure of Co-doped ZnO with and without oxygen vacancy have been investigated by the first-principles calculations based on density functional theory. It is found that the oxygen vacancy can strengthen the ferromagnetic exchange interaction between Co atoms and might be available for carrier mediation. The oxygen vacancy near to the Co atoms is more favorable for the ferromagnetic ground state.

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17

Choi, Youn-Kyu, Takuya Hoshina, Hiroaki Takeda, and Takaaki Tsurumi. "Effect of Oxygen Vacancy and Oxygen Vacancy Migration on Dielectric Response of BaTiO3-Based Ceramics." Japanese Journal of Applied Physics 50, no. 3R (March 1, 2011): 031504. http://dx.doi.org/10.7567/jjap.50.031504.

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18

Choi, Youn-Kyu, Takuya Hoshina, Hiroaki Takeda, and Takaaki Tsurumi. "Effect of Oxygen Vacancy and Oxygen Vacancy Migration on Dielectric Response of BaTiO3-Based Ceramics." Japanese Journal of Applied Physics 50 (March 22, 2011): 031504. http://dx.doi.org/10.1143/jjap.50.031504.

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19

WANG, HAI-BIN, PING PENG, YUAN-HONG TANG, DAN WANG, and LI-MING TANG. "TUNING THE "d0" FERROMAGNETISM IN In2O3 QUANTUM DOTS BY DANGLING BONDS AND VACANCY BASED ON THE FIRST-PRINCIPLE CALCULATION." Modern Physics Letters B 27, no. 10 (March 26, 2013): 1350068. http://dx.doi.org/10.1142/s0217984913500681.

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It is difficult to tune the magnetic properties of oxide diluted magnetic semiconductors because of the origin of ferromagnetism (FM) under different versions. Using first-principles band-structure calculations, we find that the surface oxygen dangling bonds and Indium vacancy may be responsible for the unexpected ferromagnetism in undoped In 2 O 3 quantum dots (QDs). The surface oxygen dangling bonds produce a magnetic moment of 6 μB, which primarily distribute on the surface oxygen atoms and an Indium vacancy ( V In ) produce a magnetic moment of 3 μB, which primarily distribute on the six O nearest neighbors of the vacancy center. The origin of the collective magnetic moments are the holes which introduced by the surface oxygen dangling bonds and Indium vacancy.

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20

Prasanna, T. R. S., and Alexandra Navrotsky. "Energetics of the oxygen vacancy order-disorder transition in Ba2In2O5." Journal of Materials Research 8, no. 7 (July 1993): 1484–86. http://dx.doi.org/10.1557/jmr.1993.1484.

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The heat capacity and the enthalpy associated with the reported oxygen vacancy order-disorder transition in Ba2In2O5 were measured by high temperature step scanning calorimetry. The transition temperature is 1205 ± 2 K. The transition appears first order or nearly so. The enthalpy and entropy of transition are 1.3 kJ/mol and 1.1 J/mol K, respectively. The latter is only 4.8% of the configurational entropy, arising from mixing one vacancy and five oxygens per formula unit, 22.5 J/mol K. This suggests that the transition involves only a small fraction of the oxygen vacancies and implies extensive short-range order, SRO, in the high temperature phase.

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21

Melikhova, Oksana, Jan Kuriplach, Jakub Čížek, Ivan Procházka, and Gerhard Brauer. "Structure and Positron Characteristics of Basic Open Volume Defects in Zirconia." Materials Science Forum 607 (November 2008): 125–27. http://dx.doi.org/10.4028/www.scientific.net/msf.607.125.

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In this contribution we report on the theoretical study of basic vacancy-like defects in cubic zirconia and yttria stabilized zirconia. In particular, we concentrate on oxygen vacancy, zirconium vacancy and oxygen vacancy – yttrium complex. Relaxed atomic configurations of studied defects are obtained by means of an ab initio pseudopotential method within the supercell approach. Positron characteristics, like positron lifetime and binding energy to defects, are calculated using self-consistent electron densities and potentials taken from ab initio calculations.

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22

Good, Brian S. "Kinetic Monte Carlo Simulation of Oxygen Diffusion in Ytterbium Disilicate." MRS Advances 1, no. 17 (2016): 1203–8. http://dx.doi.org/10.1557/adv.2015.54.

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ABSTRACTYtterbium disilicate is of interest as a potential environmental barrier coating for aerospace applications, notably for use in next generation jet turbine engines. In such applications, the transport of oxygen and water vapor through these coatings to the ceramic substrate is undesirable if high temperature oxidation is to be avoided. In an effort to understand the diffusion process in these materials, we have performed kinetic Monte Carlo simulations of vacancy-mediated and interstitial oxygen diffusion in Ytterbium disilicate. Oxygen vacancy and interstitial site energies, vacancy and interstitial formation energies, and migration barrier energies were computed using Density Functional Theory. We have found that, in the case of vacancy-mediated diffusion, many potential diffusion paths involve large barrier energies, but some paths have barrier energies smaller than one electron volt. However, computed vacancy formation energies suggest that the intrinsic vacancy concentration is small. In the case of interstitial diffusion, migration barrier energies are typically around one electron volt, but the interstitial defect formation energies are positive, with the result that the disilicate is unlikely to exhibit experience significant oxygen permeability except at very high temperature.

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23

Raitani, Kartik, Manu Prakash Maurya, Hari Krishna Rajan, C. Manjunatha, Chandresh Rastogi, and Gyanprakash Devendranath Maurya. "Optimization of Ascorbic Acid Contents in Preparation of Cobalt Oxide for Highest Oxygen Evolution Activity." ECS Meeting Abstracts MA2022-02, no. 48 (October 9, 2022): 1872. http://dx.doi.org/10.1149/ma2022-02481872mtgabs.

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The activity of the cobalt oxide (Co3O4) material towards the oxygen evolution reaction is governed by cobalt oxidation states present at the surface. The fabrication methodology decides the concentration of Co+2 and Co+3 at the Co3O4 surface. We used ascorbic acid as a fuel (reductant) for cobalt oxide synthesis. On the variation of the precursor ratio (cobalt nitrate to ascorbic acid) 1:0.5, 1:1, 1:2, and 1:4, the Co+3 and Co+2 content at the surface increases and decreases, while the oxygen vacancy decreases with increasing the ascorbic acid content. The combined effect of oxygen vacancy with Co+2 and Co+3 contents shows the maxima activity for 1:1 sample. Further, low oxygen vacancy with moderate Co+2 and Co+3 contents show low activity compared to the 1:1 sample. Also, high oxygen vacancy with low Co+2 and Co+3 contents show low activity compared to the 1:1 sample. Thus, high Co+2 and Co+3 contents with moderate oxygen vacancy give the highest activity towards the oxygen evolution reaction. The Tafel analysis further supports the above with the help of the Tafel slope. The Tafel slope of the 1:1 sample shows 55.12 mV/dec. Finally, the impedance analysis supports the above by showing the lowest value for the adsorption resistance of the 1:1 sample. Thus, the above study showed that at the ascorbic acid's optimized value, the cobalt oxide showed the highest activity via the moderate oxygen vacancy and highest Co+2 and Co+3 content.

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24

Wang, M., M. Feng, and Y. Lu. "Ab initio study of the anion vacancy on anatase TiO2 (101) surface." Modern Physics Letters B 28, no. 10 (April 20, 2014): 1450076. http://dx.doi.org/10.1142/s0217984914500766.

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In this study, we have studied the electronic structure and magnetic properties of oxygen vacancy on anatase TiO 2 (101) surface using density functional theory (DFT) calculations. The results show that only the vacancy of threefold-coordinated oxygen ( O 3c ) can introduce the magnetism on (101) surface. The spins induced by the O 3c vacancy will form a stable ferromagnetic state, and it can introduce a magnetic moment of 1.05 μ B . Moreover, the magnetic moment mainly results from the d orbitals of three low-charge-state Ti ions adjacent to the O 3c vacancy. The O 3c vacancy on (101) surface can also result in a localized state of spin polarization in the bandgap, which is about 0.22 eV below the Fermi energy. Our findings imply that the oxygen vacancy on the surface may be responsible for the unexpected ferromagnetism in pristine TiO 2 film. The experimentally observed d0-ferromagnetism behavior in TiO 2 system is in good agreement with our calculated results.

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25

Gottschalk, S., H. Hahn, S. Flege, and A. G. Balogh. "Oxygen vacancy kinetics in ferroelectric PbZr0.4Ti0.6O3." Journal of Applied Physics 104, no. 11 (December 2008): 114106. http://dx.doi.org/10.1063/1.2988902.

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26

Wang, H., A. Chroneos, D. Hall, E. N. Sgourou, and U. Schwingenschlögl. "Phosphorous–vacancy–oxygen defects in silicon." Journal of Materials Chemistry A 1, no. 37 (2013): 11384. http://dx.doi.org/10.1039/c3ta12167d.

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27

Markevich, V. P., V. V. Litvinov, L. Dobaczewski, J. L. Lindström, L. I. Murin, S. V. Vetrov, I. D. Hawkins, and A. R. Peaker. "Vacancy–oxygen complex in Ge crystals." Physica B: Condensed Matter 340-342 (December 2003): 844–48. http://dx.doi.org/10.1016/j.physb.2003.09.227.

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28

Krekels, T., G. Van Tendeloo, S. Amelinckx, J. Karpinski, E. Kaldis, and S. Rusiecki. "Oxygen‐vacancy ordering in Y2Ba4Cu7O15−ε." Applied Physics Letters 59, no. 23 (December 2, 1991): 3048–50. http://dx.doi.org/10.1063/1.105789.

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29

Gazquez, J., M. Varela, MP Oxley, MA Torija, M. Sharma, C. Leighton, and SJ Pennycook. "EELS imaging of oxygen vacancy ordering." Microscopy and Microanalysis 14, S2 (August 2008): 1354–55. http://dx.doi.org/10.1017/s1431927608084717.

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30

Scharfschwerdt, R., O. F. Schirmer, H. Krösz, and Th W. Kool. "Oxygen vacancy related defects in batio3." Ferroelectrics 185, no. 1 (September 1996): 9–12. http://dx.doi.org/10.1080/00150199608210467.

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31

You, Zhi‐pu, Min Gong, Ji‐yong Chen, and J. W. Corbett. "Iron‐vacancy‐oxygen complex in silicon." Journal of Applied Physics 63, no. 2 (January 15, 1988): 324–26. http://dx.doi.org/10.1063/1.340297.

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32

Warren, William L., Karel Vanheusden, Duane Dimos, Gordon E. Pike, and Bruce A. Tuttle. "Oxygen Vacancy Motion in Perovskite Oxides." Journal of the American Ceramic Society 79, no. 2 (February 1996): 536–38. http://dx.doi.org/10.1111/j.1151-2916.1996.tb08162.x.

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33

Yuan, Fenglin, Yanwen Zhang, and William J. Weber. "Vacancy–Vacancy Interaction Induced Oxygen Diffusivity Enhancement in Undoped Nonstoichiometric Ceria." Journal of Physical Chemistry C 119, no. 23 (May 29, 2015): 13153–59. http://dx.doi.org/10.1021/acs.jpcc.5b01317.

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34

Reyes-Gasga, J., T. Krekels, G. Van Tendeloo, J. Van Landuyt, S. Amelinckx, M. Verwey, and W. H. M. Bruggink. "Vacancy-ordered superstructures in YBa2Cu3Ox." Proceedings, annual meeting, Electron Microscopy Society of America 47 (August 6, 1989): 166–67. http://dx.doi.org/10.1017/s042482010015280x.

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YBa2Cu3Ox samples with different oxygen content were prepared in bulk form by the constant stoichiometry method. All material was initially equilibrated at 840°C during one hour in order to remove traces of CO2 and water. The temperature is subsequently lowered to 340°C for a four hour anneal. Afterwards different samples are brought at different equilibration temperatures between 340°C and 940°C. Final cooling to room temperature is done at a rate of 240°C/h. keeping the weight obtained at the equilibration temperature constant; this is performed by monitoring the oxygen partial pressure. The method decouples oxygen contents and cooling rates (and hence the degree of order). Material was prepared with an accurate oxygen content of x=6.25, 6.5, 6.625, 6.75, 6.875 and 6.98.Apart from the X=6.25 material, all investigated samples had an orthorhombic structure with a b/a ratio increasing with the oxygen content. Such samples are characterised by the presence of (110) twinning.

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35

Yin, Xiaoyan, Robert Spatschek, Norbert H. Menzler, and Claas Hüter. "A Pragmatic Transfer Learning Approach for Oxygen Vacancy Formation Energies in Oxidic Ceramics." Materials 15, no. 8 (April 14, 2022): 2879. http://dx.doi.org/10.3390/ma15082879.

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Lower oxygen vacancy formation energy is one of the requirements for air electrode materials in solid oxide cells applications. We introduce a transfer learning approach for oxygen vacancy formation energy prediction for some ABO3 perovskites from a two-species-doped system to four-species-doped system. For that, an artificial neural network is used. Considering a two-species-doping training data set, predictive models are trained for the determination of the oxygen vacancy formation energy. To predict the oxygen vacancy formation energy of four-species-doped perovskites, a formally similar feature space is defined. The transferability of predictive models between physically similar but distinct data sets, i.e., training and testing data sets, is validated by further statistical analysis on residual distributions. The proposed approach is a valuable supporting tool for the search for novel energy materials.

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36

Meng, Chao, Mengchang Lin, Xuechun Sun, Xiaodong Chen, Xuemin Chen, Xiwen Du, and Yue Zhou. "Laser synthesis of oxygen vacancy-modified CoOOH for highly efficient oxygen evolution." Chemical Communications 55, no. 20 (2019): 2904–7. http://dx.doi.org/10.1039/c8cc08951e.

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37

Eglitis, Roberts I., Juris Purans, Anatoli I. Popov, and Ran Jia. "Tendencies in ABO3 Perovskite and SrF2, BaF2 and CaF2 Bulk and Surface F-Center Ab Initio Computations at High Symmetry Cubic Structure." Symmetry 13, no. 10 (October 12, 2021): 1920. http://dx.doi.org/10.3390/sym13101920.

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We computed the atomic shift sizes of the closest adjacent atoms adjoining the (001) surface F-center at ABO3 perovskites. They are significantly larger than the atomic shift sizes of the closest adjacent atoms adjoining the bulk F-center. In the ABO3 perovskite matrixes, the electron charge is significantly stronger confined in the interior of the bulk oxygen vacancy than in the interior of the (001) surface oxygen vacancy. The formation energy of the oxygen vacancy on the (001) surface is smaller than in the bulk. This microscopic energy distinction stimulates the oxygen vacancy segregation from the perovskite bulk to their (001) surfaces. The (001) surface F-center created defect level is nearer to the (001) surface conduction band (CB) bottom as the bulk F-center created defect level. On the contrary, the SrF2, BaF2 and CaF2 bulk and surface F-center charge is almost perfectly confined to the interior of the fluorine vacancy. The shift sizes of atoms adjoining the bulk and surface F-centers in SrF2, CaF2 and BaF2 matrixes are microscopic as compared to the case of ABO3 perovskites.

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38

Cui, Jie, Shuhua Liang, Xianhui Wang, and Jianmin Zhang. "First principles study of oxygen vacancies in (Mo + C)-doped anatase TiO2." Modern Physics Letters B 29, no. 14 (May 29, 2015): 1550072. http://dx.doi.org/10.1142/s0217984915500724.

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The structural and electronic properties of neutral oxygen vacancies in ( Mo + C )-doped anatase TiO 2 were investigated using frozen-core projector-augmented wave (PAW) method within GGA +U approximation. Six possible oxygen vacancy sites were considered in the present work. The results show that the octahedral vertex adjacent to Mo and opposite from C is the most stable position for oxygen vacancy based on the results of the formation energy. The Fermi level is located at above the bottom of the conduction band and a typical n-type metallic behavior occurs as a result of the oxygen vacancy appeared in ( Mo + C ) doped TiO 2.

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39

Chu, Qi, Jingmeng Li, Sila Jin, Shuang Guo, Eungyeong Park, Jiku Wang, Lei Chen, and Young Mee Jung. "Charge-Transfer Induced by the Oxygen Vacancy Defects in the Ag/MoO3 Composite System." Nanomaterials 11, no. 5 (May 14, 2021): 1292. http://dx.doi.org/10.3390/nano11051292.

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In this paper, an Ag/MoO3 composite system was cosputtered by Ar plasma bombardment on a polystyrene (PS) colloidal microsphere array. The MoO3 formed by this method contained abundant oxygen vacancy defects, which provided a channel for charge transfer in the system and compensated for the wide band gap of MoO3. Various characterization methods strongly demonstrated the existence of oxygen vacancy defects and detected the properties of oxygen vacancies. 4-Aminothiophenol (p-aminothiophenol, PATP) was used as a candidate surface-enhanced Raman scattering (SERS) probe molecule to evaluate the contribution of the oxygen vacancy defects in the Ag/MoO3 composite system. Interestingly, oxygen vacancy defects are a kind of charge channel, and their powerful effect is fully reflected in their SERS spectra. Increasing the number of charge channels and increasing the utilization rate of the channels caused the frequency of SERS characteristic peaks to shift. This interesting phenomenon opens up a new horizon for the study of SERS in oxygen-containing semiconductors and provides a powerful reference for the study of PATP.

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40

Varela, J. A., L. A. Perazolli, J. A. Cerri, E. R. Leite, and E. Longo. "Sintering of tin oxide and its applications in electronics and processing of high purity optical glasses." Cerâmica 47, no. 302 (June 2001): 117–23. http://dx.doi.org/10.1590/s0366-69132001000200010.

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Tin oxide is an n type semiconductor material with a high covalent behavior. Mass transport in this oxide depends on the surface state promoted by atmosphere or by the solid solution of aliovalent oxide doping. The sintering and grain grow of this type of oxide powder is then controlled by atmosphere and by extrinsic oxygen vacancy formation. For pure SnO2 powder the surface state depends only in the interaction of atmosphere molecules with the SnO2 surface. Inert atmosphere like argon promotes oxygen vacancy formation at the surface due to the reduction of SnO 2 to SnO at surface and liberation of oxygen molecules forming an oxygen vacancy. As a consequence, surface diffusion is enhanced leading to grain coarsening, but no densification. Oxygen atmosphere inhibits the SnO2 reduction decreasing the surface oxygen vacancy concentration. Additions of dopants with lower valence at sintering temperature create extrinsic charged oxygen vacancies that promote mass transport at grain boundary leading to densification and grain growth of this polycrystalline oxide. Cobalt and niobium doped SnO2 ceramics exhibit varistor behavior, which can be applied in electronics. Moreover, SnO2 ceramics are chemically inert and can be applied in form of crucibles to melt some optical glasses.

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41

Mastrikov, Yuri A., Denis Gryaznov, Maksim N. Sokolov, Guntars Zvejnieks, Anatoli I. Popov, Roberts I. Eglitis, Eugene A. Kotomin, and Maxim V. Ananyev. "Oxygen Vacancy Formation and Migration within the Antiphase Boundaries in Lanthanum Scandate-Based Oxides: Computational Study." Materials 15, no. 7 (April 6, 2022): 2695. http://dx.doi.org/10.3390/ma15072695.

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The atomic structure of antiphase boundaries in Sr-doped lanthanum scandate (La1−xSrxScO3−δ) perovskite, promising as the proton conductor, was modelled by means of DFT method. Two structural types of interfaces formed by structural octahedral coupling were constructed: edge- and face-shared. The energetic stability of these two interfaces was investigated. The mechanisms of oxygen vacancy formation and migration in both types of interfaces were modelled. It was shown that both interfaces are structurally stable and facilitate oxygen ionic migration. Oxygen vacancy formation energy in interfaces is lower than that in the regular structure, which favours the oxygen vacancy segregation within such interfaces. The calculated energy profile suggests that both types of interfaces are advantageous for oxygen ion migration in the material.

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42

Перевалов, T. B. "Моделирование атомной и электронной структуры вакансий и поливакансий кислорода в ZrO-=SUB=-2-=/SUB=-." Физика твердого тела 60, no. 3 (2018): 421. http://dx.doi.org/10.21883/ftt.2018.03.45537.03d.

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AbstractCubic, tetragonal, and monoclinic phases of zirconium oxide with oxygen vacancies and polyvacancies are studied by quantum chemical modeling of the atomic and electronic structure. It is demonstrated that an oxygen vacancy in ZrO_2 may act as both an electron trap and a hole one. An electron added to the ZrO_2 structure with an oxygen vacancy is distributed between two neighboring Zr atoms and is a bonding orbital by nature. It is advantageous for each subsequent O vacancy to form close to the already existing ones; notably, one Zr atom has no more than two removed O atoms related to it. Defect levels from oxygen polyvacancies are distributed in the bandgap with preferential localization in the vicinity of the oxygen monovacancy level.

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43

James, Christine, Yan Wu, Brian Sheldon, and Yue Qi. "Computational Analysis of Coupled Anisotropic Chemical Expansion in Li2-XMnO3-δ." MRS Advances 1, no. 15 (2016): 1037–42. http://dx.doi.org/10.1557/adv.2016.48.

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ABSTRACTDuring the activation and charge process, vacancies are generated in the Li2MnO3 component in lithium-rich layered cathode materials. The chemical expansion coefficient tensor associated with oxygen vacancies, lithium vacancies and a Li-O vacancy pair were calculated for Li2-xMnO3-δ. The chemical expansion coefficient was larger for oxygen vacancies than for lithium vacancies in most directions. Additionally, the chemical expansion coefficient for a Li-O vacancy pair was shown to not be a linear sum of the chemical expansion coefficients of the two vacancy types, suggesting that the oxygen vacancies and lithium vacancies in Li2-XMnO3-δ exhibit a coupling effect.

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44

Liu, Jianqiao, Wanqiu Wang, Zhaoxia Zhai, Guohua Jin, Yuzhen Chen, Wusong Hong, Liting Wu, and Fengjiao Gao. "Influence of Oxygen Vacancy Behaviors in Cooling Process on Semiconductor Gas Sensors: A Numerical Analysis." Sensors 18, no. 11 (November 14, 2018): 3929. http://dx.doi.org/10.3390/s18113929.

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The influence of oxygen vacancy behaviors during a cooling process in semiconductor gas sensors is discussed by the numerical analysis method based on the gradient-distributed oxygen vacancy model. A diffusion equation is established to describe the behaviors of oxygen vacancies, which follows the effects of diffusion and exclusion in the cooling process. Numerical analysis is introduced to find the accurate solutions of the diffusion equation. The solutions illustrate the oxygen vacancy distribution profiles, which are dependent on the cooling rate as well as the temperature interval of the cooling process. The gas-sensing characteristics of reduced resistance and response are calculated. Both of them, together with oxygen vacancy distribution, show the grain size effects and the re-annealing effect. It is found that the properties of gas sensors can be controlled or adjusted by the designed cooling process. The proposed model provides a possibility for sensor characteristics simulations, which may be beneficial for the design of gas sensors. A quantitative interpretation on the gas-sensing mechanism of semiconductors has been contributed.

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45

Yang, Min, Genli Shen, Qi Wang, Ke Deng, Mi Liu, Yunfa Chen, Yan Gong, and Zhen Wang. "Roles of Oxygen Vacancies of CeO2 and Mn-Doped CeO2 with the Same Morphology in Benzene Catalytic Oxidation." Molecules 26, no. 21 (October 21, 2021): 6363. http://dx.doi.org/10.3390/molecules26216363.

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Mn-doped CeO2 and CeO2 with the same morphology (nanofiber and nanocube) have been synthesized through hydrothermal method. When applied to benzene oxidation, the catalytic performance of Mn-doped CeO2 is better than that of CeO2, due to the difference of the concentration of O vacancy. Compared to CeO2 with the same morphology, more oxygen vacancies were generated on the surface of Mn-doped CeO2, due to the replacement of Ce ion with Mn ion. The lattice replacement has been analyzed through XRD, Raman, electron energy loss spectroscopy and electron paramagnetic resonance technology. The formation energies of oxygen vacancy on the different exposed crystal planes such as (110) and (100) for Mn-doped CeO2 were calculated by the density functional theory (DFT). The results show that the oxygen vacancy is easier to be formed on the (110) plane. Other factors influencing catalytic behavior have also been investigated, indicating that the surface oxygen vacancy plays a crucial role in catalytic reaction.

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46

Zeng, Zhong-Liang. "First-Principles Study on the Structural and Electronic Properties of N Atoms Doped-Rutile TiO2of Oxygen Vacancies." Advances in Materials Science and Engineering 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/670243.

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For the propose of considering the actual situation of electronic neutral, a simulation has been down on the basis of choosing the position of dual N and researching the oxygen vacancy. It is found that the reason why crystal material gets smaller is due to the emergence of impurity levels. By introducing the oxygen vacancy to the structure, the results show that while the oxygen vacancy is near the two nitrogen atoms which have a back to back position, its energy gets the lowest level and its structure gets the most stable state. From its energy band structure and density, the author finds that the impurity elements do not affect the migration of Fermi level while the oxygen vacancy has been increased. Instead of that, the conduction band of metal atoms moves to the Fermi level and then forms the N-type semiconductor material, but the photocatalytic activity is not as good as the dual N-doping state.

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47

Börgers, Jacqueline M., and Roger A. De Souza. "The surprisingly high activation barrier for oxygen-vacancy migration in oxygen-excess manganite perovskites." Physical Chemistry Chemical Physics 22, no. 25 (2020): 14329–39. http://dx.doi.org/10.1039/d0cp01281e.

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48

Zhang, Xinping, Fawei Tang, Meng Wang, Wangbin Zhan, Huaxin Hu, Yurong Li, Richard H. Friend, and Xiaoyan Song. "Femtosecond visualization of oxygen vacancies in metal oxides." Science Advances 6, no. 10 (March 2020): eaax9427. http://dx.doi.org/10.1126/sciadv.aax9427.

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Oxygen vacancies often determine the electronic structure of metal oxides, but existing techniques cannot distinguish the oxygen-vacancy sites in the crystal structure. We report here that time-resolved optical spectroscopy can solve this challenge and determine the spatial locations of oxygen vacancies. Using tungsten oxides as examples, we identified the true oxygen-vacancy sites in WO2.9 and WO2.72, typical derivatives of WO3 and determined their fingerprint optoelectronic features. We find that a metastable band with a three-stage evolution dynamics of the excited states is present in WO2.9 but is absent in WO2.72. By comparison with model bandstructure calculations, this enables determination of the most closely neighbored oxygen-vacancy pairs in the crystal structure of WO2.72, for which two oxygen vacancies are ortho-positioned to a single W atom as a sole configuration among all O─W bonds. These findings verify the existence of preference rules of oxygen vacancies in metal oxides.

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49

Varela, J. A., L. A. Perazolli, E. Longo, E. R. Leite, and J. A. Cerri. "Effect of atmosphere and dopants on sintering of SnO2." Science of Sintering 34, no. 1 (2002): 23–31. http://dx.doi.org/10.2298/sos0201023v.

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Tin oxide is an n type semiconductor material with a high covalent behavior. Mass transport in this oxide depends on the surface state promoted by atmosphere or by the solid solution of aliovalent oxide doping. The sintering and grain growth of this type of oxide powder is then controlled by atmosphere and by extrinsic oxygen vacancy formation. For pure SnO2 powder the surface state depends only on the interaction of atmosphere molecules with the SnO2 surface. Inert atmosphere like argon or helium promotes oxygen vacancy formation at the surface due to reduction of SnO2 to SnO at the surface and liberation of oxygen molecules forming oxygen vacancies. As a consequence surface diffusion is enhanced leading to grain coarsening but no densification. Oxygen atmosphere inhibits SnO2 reduction by decreasing the surface oxygen vacancy concentration. Addition of dopants with lower valence at the sintering temperature creates extrinsic charged oxygen vacancies that promote mass transport at the grain boundary leading to densification and grain growth of this polycrystalline oxide.

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50

Panomsuwan, Gasidit, and Nagahiro Saito. "Effect of Oxygen Partial Pressure on Crystal Structure, Oxygen Vacancy, and Surface Morphology of Epitaxial SrTiO3 Thin Films Grown by Ion Beam Sputter Deposition." Oxygen 1, no. 1 (September 2, 2021): 62–72. http://dx.doi.org/10.3390/oxygen1010007.

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Epitaxial SrTiO3 (STO) thin films were grown on (001)-oriented LaAlO3 (LAO) substrates at 800 °C by an ion beam sputter deposition (IBSD). Oxygen partial pressure (PO2) was varied at 1.5 × 10−5, 1.5 × 10−4, and 1.5 × 10−3 Torr during the growth. The effects of PO2 on crystal structure, oxygen vacancy, and surface morphology of the STO films were investigated and are discussed to understand their correlation. It was found that PO2 played a significant role in influencing the crystal structure, oxygen vacancy, and surface morphology of the STO films. All STO films grew on the LAO substrates under a compressive strain along an in-plane direction (a- and b-axes) and a tensile strain along the growth direction (c-axis). The crystalline quality of STO films was slightly improved at higher PO2. Oxygen vacancy was favorably created in the STO lattice grown at low PO2 due to a lack of oxygen during growth and became suppressed at high PO2. The existence of oxygen vacancy could result in a lattice expansion in both out-of-plane and in-plane directions due to the presence of Ti3+ instead of Ti4+ ions. The surface roughness of the STO films gradually decreased and was nearly close to that of the bare LAO substrate at high PO2, indicating a two-dimensional (2D) growth mode. The results presented in this work provide a correlation among crystal structure, oxygen vacancy, and surface morphology of the epitaxial STO films grown by IBSD, which form a useful guideline for further study.

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Journal articles on the topic 'Oxygen vacancy'

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