Results 251 to 260 of about 83,687 (300)

Surface reactivity of MgO oxygen vacancies

Catalysis Today, 1999
Abstract The interaction of gas-phase molecules (O 2 , CO and H 2 ) with oxygen vacancies (F s centers) on the MgO(1 0 0) surface was studied by cluster models ab initio wave functions. The F s centers exhibit a high reactivity towards O 2 , CO and H 2 at variance with the regular sites of the MgO surface.
Gianfranco PACCHIONI, FERRARI, Anna Maria   +1 more
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Vacancy–oxygen complex in Ge crystals

Physica B: Condensed Matter, 2003
Vacancy-oxygen (VO) complexes in Ge crystals have been studied by means of high-resolution infrared absorption and deep-level transient spectroscopy (Laplace DLTS) measurements. It is argued that the VO center in Ge has three charge states: double negative (VO--), single negative (VO -) and neutral (VO0) with the corresponding energy levels at E( - /-)
Markevich, V. P., Litvinov, V. V., Dobaczewski, L., Lindström, J. L., Murin, L. I., Vetrov, S. V., Hawkins, I. D., Peaker, A. R.   +7 more
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Oxygen Vacancy Migration in MLCCS

Pan Pacific Symposium, 2018
ABSTRACT The multilayer ceramic capacitor (MLCC) has become a widely used electronics component. The MLCC technologies have gone through a number of material and process changes such as the shift from precious metal electrode (PME) configurations which were predominantly silver/palladium to base metal electrodes (BME) dominated by ...
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The Oxygen Vacancy in Crystal Phases of WO₃ [PDF]

The Journal of Physical Chemistry B, 2005
The oxygen vacancy in WO(3) has previously been implicated in the electrochromism mechanism in this material. Previous theoretical calculations on the oxygen vacancy in WO(3) have not considered the full range of crystal structures adopted by the material. Here we report studies of the oxygen vacancy in seven crystal phases.
Chadwick, Alan V., Chatten, Ryan, Rougier, A., Lindan, Philip J. D.   +3 more
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Tuning Oxygen Vacancies in Oxides by Configurational Entropy

ACS Applied Materials & Interfaces, 2023
Tuning surface oxygen vacancies is important for oxide catalysts. Doping elements with different chemical valence states or different atomic radii into host oxides is a common method to create oxygen vacancies. However, the concentration of oxygen vacancies in oxide catalysts is still limited to the amount of foreign dopants that can be tolerated ...
Mengyuan Zhang, Xiaolan Duan, Ying Gao, Shuangshuang Zhang, Xiaoyan Lu, Kongliang Luo, Jian Ye, Xiaopeng Wang, Qiang Niu, Pengfei Zhang, Sheng Dai   +10 more
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On the identification of the oxygen vacancy in HfO2

Microelectronic Engineering, 2011
The single positively charge oxygen vacancy in HfO"2 is found to undergo a symmetry breaking distortion to a C"2"v symmetry, driven by electron localization, which is consistent with the experimentally observed electron spin resonance signal. This completes the identity of the oxygen vacancy defect in HfO"2 and ZrO"2 as the active defect that affects ...
S.J. Clark, L. Lin, J. Robertson
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Oxygen vacancies on MgO(100)

Surface Science, 1996
Abstract The electronic and atomic structures of nondashstoichiometric MgO {100} surfaces, with several densities of neutral oxygen vacancies, have been studied using a semi-empirical Hartree-Fock method associated with a geometry optimization code. The oxygen vacancies are periodically repeated in the surface top layer with equal spacings.
E. Castanier, C. Noguera
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Oxygen vacancy chemistry in oxide cathodes

Chemical Society Reviews
This review focuses on the chemical thermodynamics and reaction kinetics of intrinsic and anionic redox-mediated oxygen vacancies in oxide cathodes.
Yu-Han Zhang, Shu Zhang, Naifang Hu, Yuehui Liu, Jun Ma, Pengxian Han, Zhiwei Hu, Xiaogang Wang, Guanglei Cui   +8 more
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Properties of the oxygen vacancy in ZnO

Applied Physics A, 2007
As-grown ZnO bulk crystals and crystals annealed in vacuum, oxygen, or zinc vapour were characterized by electrical, optical and magnetic resonance spectroscopy. The experiments show that the residual carrier concentration is caused by residual H, Al, Ga and oxygen vacancies (VO) in the material.
D.M. Hofmann, D. Pfisterer, J. Sann, B.K. Meyer, R. Tena-Zaera, V. Munoz-Sanjose, T. Frank, G. Pensl   +7 more
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Oxygen vacancies in lithium niobate

Applied Physics Letters, 1983
Optical absorption peaks at 760 and 500 nm in LiNbO3 are assigned to oxygen vacancies containing one and two electrons, respectively. The 500-nm band appears after annealing above approximately 500 °C in a vacuum, i.e., a reducing atmosphere, and continues to grow with increasing anneal temperature.
K. L. Sweeney, L. E. Halliburton
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