Effect of Chlorine Atoms for Development of Aluminum Corrosion

2016 ◽  
Vol 879 ◽  
pp. 2170-2174 ◽  
Author(s):  
Junko Yamashita ◽  
Norio Nunomura

Computational density functional theory (DFT) model of the adsorption of chlorine atoms onto the perfect Al (111) surface has been performed. The structural and electronic properties of chlorine atoms adsorbed on the surface are investigated within a supercell approach for chlorine coverages of 0.25, 0.33, 0.5 and 1 ML respectively. It is found that the adsorbates prefer on-top sites over bridge, hcp and fcc sites in low coverage while fcc sites in high coverage, and the binding energy decrease with increase of coverage due to the interactions of chlorine atoms. The discussion of geometrical and electronic analysis by plotting differential charge density distribution and projected density of states (PDOS) are presented.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad Qasemnazhand ◽  
Farhad Khoeini ◽  
Farah Marsusi

AbstractIn this study, based on density functional theory, we propose a new branch of pseudo-fullerenes which contain triple bonds with sp hybridization. We call these new nanostructures fullerynes, according to IUPAC. We present four samples with the chemical formula of C4nHn, and the structures derived from fulleranes. We compare the structural and electronic properties of these structures with those of two common fullerenes and fulleranes systems. The calculated electron affinities of the sampled fullerynes are negative, and much smaller than those of fullerenes, so they should be chemically more stable than fullerenes. Although fulleranes also exhibit higher chemical stability than fullerynes, but pentagon or hexagon of the fullerane structures cannot pass ions and molecules. Applications of fullerynes can be included in the storage of ions and gases at the nanoscale. On the other hand, they can also be used as cathode/anode electrodes in lithium-ion batteries.


2012 ◽  
Vol 26 (32) ◽  
pp. 1250217
Author(s):  
XIAO-XIAO SUN ◽  
ZHI-RU REN ◽  
DAO-GUANG WANG

High pressure studies of BiI 3 at 0 K are performed using first-principles pseudopotential calculations within the framework of density functional theory. The calculations indicate that BiI 3 undergoes a structural transition from rhombohedral R-3 phase to monoclinic P2 1/c phase at 7 GPa which is accompanied by a 5.8% volume collapse. In addition, we find that P2 1/c phase prevails about 60 GPa range and transforms to cubic Fm-3m phase at 68 GPa, and finally takes the orthorhombic Pnma phase at high pressures up to 133 GPa. The structural and electronic properties of four competitive structures are also calculated. The analysis of density of states reveals that BiI 3 has semiconductor-metal transition at about 61 GPa, which also demonstrates the metallic nature of both Fm-3m and Pnma phases.


2018 ◽  
Vol 786 ◽  
pp. 384-392 ◽  
Author(s):  
Hussein Y. Ammar

The structural and electronic properties of Li, Mg and Al deposited ZnO nanocages and their effects on the adsorption of formaldehyde molecule have been investigated using the density functional theory (DFT) computations. To understand the behavior of the adsorbed CH2O molecule on the ZnO nanocage, results of DFT calculations of the M-deposited nanocages (M=Li, Mg and Al), as well as complex systems consisting of the adsorbed CH2O molecule on M-deposited ZnO nanocage were reported. The results presented include adsorption energies, bond lengths, electronic configurations, density of states and molecular orbitals. It was found that, the most energetically stable adsorption configurations of CH2O molecule on the bare ZnO leads to 12% dilation in C=O bond length of CH2O and 14% decrease in HOMO-LUMO gap of ZnO cluster. The most energetically stable adsorption configurations of CH2O molecule on Li, Mg and Al-deposited ZnO lead to 4%, 4% and 11% dilation in C=O bond length of CH2O and-0.66, -45 and , +66% change in HOMO-LUMO gap of ZnO nanocages, respectively. The interaction between CH2O with bare ZnO and M-deposited ZnO nanocages is attributed to charge transfer mechanism. These results may be meaningful for CH2O degradation and detection.


In the present work, we have studied intercalated Transition Metal Dichalcogenides (TMDC) MTiS2 compounds (M = Cr, Mn, Fe) by Density Functional Theory (DFT) with Generalized Gradient Approximation (GGA). We have computed the structural and electronic properties by using first principle method in QUANTUM ESPRESSO computational code with an ultra-soft pseudopotential. A guest 3d transition metal M (viz; Cr, Mn, Fe) can be easily intercalated in pure transition metal dichalcogenides compound like TiS2. In the present work, the structural optimization, electronic properties like the energy band structure, density of states (DoS), partial or projected density of states (PDoS) and total density of states (TDoS) are reported. The energy band structure of MTiS2 compound has been found overlapping energy bands in the Fermi region. We conclude that the TiS2 intercalated compound has a small band gap while the doped compound with guest 3d-atom has metallic behavior as shown form its overlapped band structure.


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