Results 61 to 70 of about 115,078 (291)

Ab initio study of oxygen vacancies in α-quartz [PDF]

Journal of Non-Crystalline Solids, 1997
Extrinsic levels, formation energies, and relaxation geometries are calculated ab initio for oxygen vacancies in alpha-quartz SiO2. The vacancy is found to be thermodynamically stable in the charge states Q=+3, Q=0, Q=--2, and Q=-3. The charged states are stabilized by large and asymmetric distortions near the vacancy site.
CARBONARO, CARLO MARIA, FIORENTINI, VINCENZO, Massidda S.   +2 more
openaire   +3 more sources

Influence of an Argon/Silane Atmosphere on the Temperature of a Thermal Plasma

Advanced Engineering Materials, EarlyView.
The influence of a silane‐doped argon atmosphere on the chemical composition and temperature of a thermal nontransferring argon plasma is investigated using optical emission spectroscopy. As a result of the high amount of free electrons resulting from the stepwise ionization and dissociation of the silane molecule, even a silane addition of 0.01 vol ...
Lena Kreie, David Kramer, Thomas Scheithauer, Hans Jürgen Maier, Thomas Hassel   +4 more
wiley   +1 more source

Negative oxygen vacancies in HfO$_2$ as charge traps in high-k stacks

, 2006
We calculated the optical excitation and thermal ionization energies of oxygen vacancies in m-HfO$_2$ using atomic basis sets, a non-local density functional and periodic supercell. The thermal ionization energies of negatively charged V$^-$ and V$^{2-}$
A. L. Shluger, B. H. Lee, Bersuker G., D. Muñoz Ramo, G. Bersuker, J. L. Gavartin, Saunders V.   +6 more
core   +1 more source

Handbook of Establishing and Maintaining Oxygen‐Free Atmospheres

Advanced Engineering Materials, EarlyView.
This study presents a practical framework for creating oxygen‐free atmospheres at ambient pressure using silane‐doped inert gases. The results show that ultra‐low oxygen levels and strongly reduced water content can be achieved through controlled silane dosing, drying systems, and sensor monitoring.
Sascha Jan Zimmermann, René Gustus, Lienhard Wegewitz, Wolfgang Maus‐Friedrichs   +3 more
wiley   +1 more source

Europium-Doped Ceria Nanowires as Anode for Solid Oxide Fuel Cells

Frontiers in Chemistry, 2020
CeO2-based materials have been studied intensively as anodes for intermediate temperature solid oxide fuel cells (IT-SOFCs). In this work, pristine and europium (Eu)-doped CeO2 nanowires were comprehensively investigated as anode materials for IT-SOFCs ...
Shuai Li, Shuai Li, Shuai Li, Xia Lu, Siqi Shi, Liquan Chen, Zhaoxiang Wang, Yusheng Zhao, Yusheng Zhao   +8 more
doaj   +1 more source

Effect of Oxygen Content on Surface and Subsurface Integrity During Turning of Ti–6Al–4V

Advanced Engineering Materials, EarlyView.
This study examines how oxygen content in the ambient atmosphere affects the surface and subsurface properties of Ti–6Al–4V during turning. Results show that oxygen does not influence surface roughness. However, machining in an extremely high vacuum‐adequate atmosphere increases surface hardness by up to 7.8% and induces compressive residual stresses ...
Benjamin Bergmann, Berend Denkena, Hilke Petersen, Florian Schaper   +3 more
wiley   +1 more source

Ab initio modeling of oxygen impurity atom incorporation into uranium mononitride surface and subsurface vacancies

, 2012
The incorporation of oxygen atoms has been simulated into either nitrogen or uranium vacancy at the UN(001) surface, sub-surface or central layers. For calculations on the corresponding slab models both the relativistic pseudopotentials and the method of
Arai, Atta-Fynn, Bloechl, Brooks, Carley, D. Bocharov, D. Gryaznov, E.A. Kotomin, Eckle, Evarestov, Grimes, Gryaznov, Hafner, Jaques, Kotomin, Kotomin, Kotomin, Kotomin, Kresse, Kresse, Kresse, Kresse, Kresse, Lee, Mastrikov, Monkhorst, Novoselov, Perdew, Petit, Samsel-Czekała, Sedmidubsky, Shibata, Weck, Weinberger, Wiame, Yeamans, Yongbin, Yu.F. Zhukovskii, Zhukovskii, Zhukovskii   +39 more
core   +1 more source

Oxide‐Free Titanium Coatings by Wire Arc Spraying in a Silane‐Doped Inert Atmosphere

Advanced Engineering Materials, EarlyView.
A silane‐doped argon atmosphere enables the production of oxide‐free titanium coatings via twin‐wire arc spraying at ambient pressure. This innovative approach eliminates residual oxygen, creating process conditions that prevent oxidation and nitride formation.
Manuel Rodriguez Diaz, Maik Szafarska, René Gustus, Kai Möhwald, Hans Jürgen Maier   +4 more
wiley   +1 more source

Extraction of sub-gap density of states via capacitance–voltage measurement for the erasing process in a TFT charge-trapping memory

AIP Advances, 2018
Charge-trapping memories (CTMs) based on zinc tin oxide (ZTO) semiconductor thin-film transistors (TFTs) can be programmed by a positive gate voltage and erased by a negative gate voltage in conjunction with light illumination.
Yen-Chang Chiang, Yang-Hsuan Hsiao, Jeng-Ting Li, Jen-Sue Chen   +3 more
doaj   +1 more source

Local phenomena at grain boundaries: An alternative approach to grasp the role of oxygen vacancies in metallization of VO2

Journal of Materiomics, 2018
Vanadium dioxide (VO2) undergoes an insulator to metal transition (MIT) and an accompanied phase transition from a monoclinic (M) structure to rutile (R) structure near room temperature, forming the basis for many VO2-based functional devices.
Wanheng Lu, Lai-Mun Wong, Shijie Wang, Kaiyang Zeng   +3 more
doaj   +1 more source