Theoretical Investigations of Hydrogen Atom Diffusion Rates in Xenon Matrixes

1994 ◽  
Vol 98 (51) ◽  
pp. 13766-13771 ◽  
Author(s):  
Martin D. Perry ◽  
Gilbert J. Mains ◽  
Lionel M. Raff

1993 ◽  
Vol 97 (47) ◽  
pp. 12134-12143 ◽  
Author(s):  
M. Beth Ford ◽  
Angel D. Foxworthy ◽  
G. J. Mains ◽  
Lionel M. Raff


2014 ◽  
Vol 140 (20) ◽  
pp. 204710 ◽  
Author(s):  
Nikolay G. Petrik ◽  
Rhiannon J. Monckton ◽  
Sven P. K. Koehler ◽  
Greg A. Kimmel


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Yi Liu ◽  
Yanli Li ◽  
Pengcheng Huang ◽  
Han Song ◽  
Gang Zhang


2009 ◽  
Vol 16 (06) ◽  
pp. 905-908 ◽  
Author(s):  
J. X. GUO ◽  
L. GUAN ◽  
B. GENG ◽  
Q. LI ◽  
Q. X. ZHAO ◽  
...  

Diffusion of H atom in the Ti (0001) outer-layer and inter-layer surface is studied using density functional theory based on generalized gradient approximation (GGA). The energy barriers for the hydrogen atom diffusion in different interstitial sites at the same layers or between adjacent layers are calculated. It is found that the energy barriers of H atom diffusion in the adjacent interstitial layers are bigger than that in the same interstitial layers. For the diffusion of H atom between adjacent interstitial layers, the diffusion between tetrahedral sites is easier than that between octahedral sites. While for diffusion of H atom between the same interstitial layers, the diffusion between tetrahedral sites is easier than that between tetrahedral and octahedral sites. Moreover, it is found that the most possible inside diffusion from hcp site of a hydrogen atom in the Ti (0001) outer-layer goes through tetrahedral sites.



2013 ◽  
Vol 873 ◽  
pp. 101-109 ◽  
Author(s):  
Zhi Wen Wang ◽  
Xin Jun Guo ◽  
Wei Yuan ◽  
Zhi Yan Ding

First-principles calculations within the density functional theory (DFT) have been carried out to study the interaction of hydrogen atom with transition metals (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn) doped Mg (0001) surfaces. First we have calculated the stability of the transition metals atom on the Mg surface, On the basis of the energetic criteria, all the elements except Zn prefer to substitute one of the Mg atoms from the second layer, while Zn tend to substitute one of the Mg atoms from the first layer. In the second step, we have studied the interaction between hydrogen atom and the transition metals doped Mg (0001) surface.we have studied the interaction of a hydrogen atom with the transition metals doped Mg (0001) surface. The results show that for transition metals atoms doped Mg (0001) surface in the second layer, it not only enhances the chemisorption interaction between hydrogen atom and Mg surface, but also it benefits hydrogen atom diffusion in Mg bulk with relatively more diffusion paths. However, when the Mg surface doped by elements such as Sc, Ti, V, Cu and Zn, hydrogen atom chooses to bond with transition metals atom and block the diffusion of hydrogen atom into Mg bulk, while when the Mg surface doped by elements such as Cr, Mn, Fe, Co and Ni, hydrogen atom chooses to leave from transition metals atom thereby promoting the diffusion of hydrogen atom diffusion into Mg bulk. Charge density difference plots shows that electrons are transferred from electronic states of transition metals atom to the orbital of hydrogen atom which cause attractive interactions between hydrogen atom and transition metals atom and reduce the energy barrier of the hydrogen atom diffusion into Mg bulk. Our results show that useing transition metals (Cr, Mn, Fe, Co and Ni) as catalysts for the hydrogenation/dehydrogenation of Mg bulk samples and provide more diffusion paths of hydrogen atom, they are beneficial for the diffusion of hydrogen atom to Mg bulk and improve significantly the hydrogenation kinetics property of Mg surface.



2004 ◽  
Vol 70 (20) ◽  
Author(s):  
C. Z. Zheng ◽  
C. K. Yeung ◽  
M. M. T. Loy ◽  
Xudong Xiao


2015 ◽  
Vol 27 (1) ◽  
pp. 705-710 ◽  
Author(s):  
Xiaowan Dai ◽  
Hongkun Cai ◽  
Dexian Zhang ◽  
Guifeng Chen ◽  
Yong Wang ◽  
...  


2008 ◽  
Vol 277 ◽  
pp. 133-138
Author(s):  
Liudmila V. Selezneva ◽  
Andrei V. Nazarov

This work is devoted to simulation of potential barrier spectrum for hydrogen atom and vacancy jumps in fcc- and bcc- metals taking into account the mutual effect of the point defects on the potential barrier spectrum and as a result the effect on complex defect diffusion in bcc- and fccmetals. The molecular static and the Monte Carlo methods are used. The developed model allows us to determine a diffusion coefficient of the impurity atom depending on temperature and other parameters. The simulation of point defect random walk in lattice on the basis MC-method and potential barrier spectrum has gave an impulse toward an understanding of hydrogen motion on the atomic scale in metals, which is required to determine such important parameters as the diffusion coefficient of H. As well it allows us to understand reasons of more complicated behaviour of H in realistic metal in comparison with perfect metal.



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