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Related papers: Modeling oxygen-void interactions in uranium nitri…

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The results of DFT supercell calculations of oxygen behavior upon the UN (001) and (110) surfaces as well as at the tilt grain boundary are presented. Oxygen adsorption, migration, incorporation into the surface N vacancies on (001) and…

Materials Science · Physics 2015-06-12 D. Bocharov , D. Gryaznov , Yu. F. Zhukovskii , E. A. Kotomin

The uranium mononitride (UN) is a material considered as a promising candidate for Generation-IV nuclear reactor fuels. Unfortunately, oxygen in air affects UN fuel performance and stability. Therefore, it is necessary to understand the…

Materials Science · Physics 2012-11-27 Eugene A. Kotomin , Yuri F. Zhukovkii , Dmitry Bocharov , Denis Gryaznov

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…

Materials Science · Physics 2012-11-27 Dmitry Bocharov , Denis Gryaznov , Yuri F. Zhukovskii , Eugene A. Kotomin

We investigated the impact of surface oxygen on the ion yield for He$^+$ ions scattered from different single crystalline surfaces in low-energy ion scattering. Initially clean Al(111) and Ta(111) were exposed to molecular oxygen and ion…

Materials Science · Physics 2019-09-18 Barbara Bruckner , Peter Bauer , Daniel Primetzhofer

We calculated the influence of surface tension on the barriers of oxygen ionic conductivity in nanograin ceramics. Activation energy of oxygen ions diffusion via oxygen vacancies which were considered as the dilatational centers was…

Materials Science · Physics 2007-05-23 M. D. Glinchuk , P. I. Bykov , B. Hilczer

Zr oxides and oxynitrides are promising candidates to replace precious metal cathodes in polymer electrolyte fuel cells. Oxygen reduction reaction activity in this class of materials has been correlated with the amount of oxygen vacancies,…

Materials Science · Physics 2025-02-18 Akitaka Nakanishi , Shusuke Kasamatsu , Jun Haruyama , Osamu Sugino

Uranium mononitride, UN, is considered a potential accident tolerant fuel due to its high uranium density, high thermal conductivity, and high melting point. Compared with the relatively inert UO2, UN has a high reactivity in water,…

Materials Science · Physics 2018-10-30 E. Lawrence Bright , S. Rennie , A. Siberry , K. Samani , K. Clarke , D. T. Goddard , R. Springell

The results of DFT GGA calculations on oxygen molecules adsorbed upon the (001) surface of uranium mononitride (UN) are presented and discussed. We demonstrate that O2 molecules oriented parallel to the substrate can dissociate either (i)…

Materials Science · Physics 2010-09-01 Yuri F. Zhukovskii , Dmitry Bocharov , Eugene A. Kotomin

The surface energy is one of the fundamental properties nuclei, appearing in the simplest form of the semi-empirical mass formula. The surface enery has an influence on e.g. the shape of a nucleus and its ability to deform. This in turn…

Nuclear Theory · Physics 2020-04-22 P. D. Stevenson

This study investigates the catalytic degradation of ground-level ozone on low-index stoichiometric and reduced CeO$_2$ surfaces using first-principles calculations. The presence of oxygen vacancies on the surface enhances the interaction…

Materials Science · Physics 2024-02-08 Suchitra Gupta , Joon Hwan Choi , Hojin Jeong , Seung-Cheol Lee , Satadeep Bhattacharjee

To help provide insight into the remarkable catalytic behavior of the oxygen/silver system for heterogeneous oxidation reactions, purely sub-surface oxygen, and structures involving both on-surface and sub-surface oxygen, as well as…

Materials Science · Physics 2009-11-10 Wei-Xue Li , Catherine Stampfl , Matthias Scheffler

The formation of ultrathin oxide layers on metal surfaces is a non-thermally-activated process which takes place spontaneously at very low temperatures within nanoseconds. This paper reports mechanistic details of the initial oxidation of…

Materials Science · Physics 2008-07-23 Lucio Colombi Ciacchi

We report on a computational study of the clean and oxygen-covered Rh(110) surface, based on density-functional theory within the local-density approximation. We have used plane-wave basis sets and Vanderbilt ultra-soft pseudopotentials.…

Condensed Matter · Physics 2009-10-28 Kurt Stokbro , Stefano Baroni

The aim of the present work is to introduce a thermodynamic model to describe the growth of an oxide layer on a metallic substrate. More precisely, this paper offers a study of oxygen dissolution into a solid, and its consequences on the…

Chemical Physics · Physics 2009-09-15 Nicolas Creton , Virgil Optasanu , Tony Montesin , Sébastien Garruchet , Lionel Desgranges

The structure property of non-ideal Si/GaAs heterostructures that were integrated with the ultra-thin oxide (UO) tunneling interfacial layer has been systematically investigated. Si nanomembranes (NMs) were oxidized in different time…

Fabrication, handling and disposal of nuclear fuel materials require comprehensive knowledge of their surface morphology and reactivity. Due to unavoidable contact with air components (even at low partial pressures), UN samples contain…

Materials Science · Physics 2010-09-01 Yuri F. Zhukovskii , Dmitry Bocharov , Eugene Kotomin , Robert Evarestov , Andrey V. Bandura

Oxygen vacancies at the SnO2(110) and (101) surface and subsurface sites have been studied in the framework of density functional theory by using both all-electron Gaussian and pseudopotential plane-wave methods. The all-electron…

Materials Science · Physics 2008-06-06 F. Trani , M. Causa' , D. Ninno , G. Cantele , V. Barone

Swelling of uranium dioxide with ingrowth of defects by irradiation is not fully understood. Experimental and theoretical groups have attempted to explain this phenomenon with various complex theories. In this study, experimental lattice…

Materials Science · Physics 2016-05-03 S. D. Günay

A zero-dimensional (volume-averaged) and a pseudo-one-dimensional (plug-flow) model are developed to investigate atmospheric-pressure plasma jet devices operated with He, He/O$_2$, He/N$_2$ and He/N$_2$/O$_2$ mixtures. The models are…

The influence of surface oxygen vacancies on the oxygen evolution reaction on bismuth vanadate is studied using hybrid density functional theory. Our findings reveal the thermodynamic instability of the neutral unionized defect (${\rm…

Materials Science · Physics 2023-06-19 Nicklas Österbacka , Hassan Ouhbi , Francesco Ambrosio , Julia Wiktor
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