Theoretical Investigation of Carbon Atom Adsorption and Diffusion on the Surfaces of Cu

2014 ◽  
Vol 1082 ◽  
pp. 475-479
Author(s):  
Liang Qiao ◽  
Shu Jie Liu ◽  
Xiao Ying Hu ◽  
Li Li Wang ◽  
Dong Mei Bi

The adsorption and diffusion of carbon atom on Cu (111) and (100) surfaces have been investigated based on first-principles density-functional theory. For Cu (111) surface, the hexagonal close-packed and face-centered cubic sites are the most stable sites with little energy difference in the adsorption energy. For Cu (100) surface, the hollow site is the most stable. There is charge transfer from Cu surface to the adsorbed carbon atom. Moreover, the diffusions of carbon atom on Cu surfaces have been investigated, and the results show that the diffusion of carbon atom prefers to happen on Cu (111) surface.

2015 ◽  
Vol 29 (31) ◽  
pp. 1550199 ◽  
Author(s):  
J. L. Nie ◽  
L. Ao ◽  
X. T. Zu

In this paper, first-principles calculations based on density functional theory (DFT) have been performed to investigate the adsorption of oxygen and hydrogen on [Formula: see text] and [Formula: see text] surfaces covered by monolayer (ML) of [Formula: see text]. The results have shown that the oxygen molecule tends to adsorb on fcc site on both surfaces at the coverage of 0.25 ML, which becomes degeneration with hcp site when the coverage increases to 1 ML. For both oxygen and hydrogen, the adsorption on [Formula: see text] surface are stronger than those on [Formula: see text] surface. The adsorption energy difference for oxygen on the two surfaces is [Formula: see text][Formula: see text]0.2 eV at the coverage of 1 ML, which increases to [Formula: see text][Formula: see text]0.6 eV with the coverage decreasing to 0.25 ML. The similar energy difference was also found for hydrogen adsorption. The density of states analysis have demonstrated the chemical interaction of adsorbed oxygen with both pure [Formula: see text] and [Formula: see text] surfaces with certain shift of [Formula: see text] states to lower level compared to isolated oxygen. For hydrogen adsorption, the hybridization of [Formula: see text] with [Formula: see text] states were observed for both surfaces, indicating the covalent bonding component of H–Pt bond.


2005 ◽  
Vol 864 ◽  
Author(s):  
Jinyu Zhang

AbstractUsing density functional theory (DFT) calculations within the generalized gradient approximation (GGA), we have investigated the structure, energies and diffusion behavior of Si defects including interstitial, vacancy, FFCD and divacancy in various charged states.


2005 ◽  
Vol 864 ◽  
Author(s):  
Scott A. Harrison ◽  
Thomas F. Edgar ◽  
Gyeong S. Hwang

AbstractBased on first principles density functional theory calculations, we identify the structure and diffusion pathway for a fluorine-silicon interstitial complex (F-Sii). We find the F-Sii complex to be most stable in the singly positive charge state at all Fermi leVels. At mid-gap, the complex is found to have a binding energy of 1.08 eV relative to bond-centered F+ and (110)-split Sii. We find the F-Sii complex has an overall migration barrier of 0.76 eV, which suggests that this complex may play an important role in fluorine diffusion. Our results should lead to more accurate models that describe the behavior of fluorine co-implants crystalline silicon.


2016 ◽  
Vol 12 (23) ◽  
pp. 11-23
Author(s):  
Juan Manuel Gonzalez ◽  
Johans Steeven Restrepo ◽  
Carolina Ortega Portilla ◽  
Alexander Ruden Muñoz ◽  
Federico Sequeda Osorio

Using Density Functional Theory (DFT) SiN and TiN structures were simulated, in order to study the influence of the silicon atoms insertion in the TiN lattice placed on interstitial and substitutional positions in a face centered cubic (FCC) crystalline lattice. Results showed that the SiN - FCC structure is pseudo-stable; meanwhile the tetragonal structure is stable with ceramic behavior. The TiN - FCC structure is stable with ceramic behavior similar to SiN - Tetragonal. 21% silicon atoms insertion in interstitial positions showed high induced deformation, high polarization and Si - N bond formation, indication an amorphous transition that could lead to the production of a material composed from TiN grains or nano-grains embedded in a Si - N amorphous matrix. When including 21% of silicon atoms, substituting titanium atoms, the distribution showed higher stability that could lead to the formation of different phases of the stoichiometric Ti1 -x SixNy compound.


2021 ◽  
Author(s):  
Sheena Agarwal ◽  
Kavita Joshi

Abstract<br>Identifying factors that influence interactions at the surface is still an active area of research. In this study, we present the importance of analyzing bondlength activation, while interpreting Density Functional Theory (DFT) results, as yet another crucial indicator for catalytic activity. We studied the<br>adsorption of small molecules, such as O 2 , N 2 , CO, and CO 2 , on seven face-centered cubic (fcc) transition metal surfaces (M = Ag, Au, Cu, Ir, Rh, Pt, and Pd) and their commonly studied facets (100, 110, and 111). Through our DFT investigations, we highlight the absence of linear correlation between adsorption energies (E ads ) and bondlength activation (BL act ). Our study indicates the importance of evaluating both to develop a better understanding of adsorption at surfaces. We also developed a Machine Learning (ML) model trained on simple periodic table properties to predict both, E ads and BL act . Our ML model gives an accuracy of Mean Absolute Error (MAE) ∼ 0.2 eV for E ads predictions and 0.02 Å for BL act predictions. The systematic study of the ML features<br>that affect E ads and BL act further reinforces the importance of looking beyond adsorption energies to get a full picture of surface interactions with DFT.<br>


2021 ◽  
Vol 23 (35) ◽  
pp. 19579-19589
Author(s):  
Sindy J. Rodríguez ◽  
Adriana E. Candia ◽  
Mario C. G. Passeggi ◽  
Eduardo A. Albanesi ◽  
Gustavo D. Ruano

Using first-principles calculations based on density functional theory (DFT), we study the aluminum fluoride (AlF3) intercalation in graphite as a new possibility to use this molecule in rechargeable batteries, and understand its role when used as a component of the solvent.


2017 ◽  
Vol 8 ◽  
pp. 1742-1748
Author(s):  
Fadil Iyikanat ◽  
Ali Kandemir ◽  
Cihan Bacaksiz ◽  
Hasan Sahin

Using first-principles density functional theory calculations, we investigate adsorption properties and the diffusion mechanism of a Li atom on hydrogenated single-layer α- and β-silicene on a Ag(111) surface. It is found that a Li atom binds strongly on the surfaces of both α- and β-silicene, and it forms an ionic bond through the transfer of charge from the adsorbed atom to the surface. The binding energies of a Li atom on these surfaces are very similar. However, the diffusion barrier of a Li atom on H-α-Si is much higher than that on H-β-Si. The energy surface calculations show that a Li atom does not prefer to bind in the vicinity of the hydrogenated upper-Si atoms. Strong interaction between Li atoms and hydrogenated silicene phases and low diffusion barriers show that α- and β-silicene are promising platforms for Li-storage applications.


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