scholarly journals First-principles calculation of the effect of strain on the diffusion of Ge adatoms on Si and Ge (001) surfaces

2002 ◽  
Vol 749 ◽  
Author(s):  
A. van de Walle ◽  
M. Asta ◽  
P. W. Voorhees
Keyword(s):  
First Principles ◽  
Self Assembly ◽  
Compressive Strain ◽  
Fold Increase ◽  
Characteristic Size ◽  
Activation Energies ◽  
First Principles Calculation ◽  
Reconstructed Surfaces ◽  
Surface Increase ◽  
And Diffusion

ABSTRACTFirst-principles calculations are used to calculate the strain dependencies of the binding and diffusion-activation energies for Ge adatoms on both Si(001) and Ge(001) c(4×2) reconstructed surfaces. Our calculations reveal that over the range of strains typically sampled during quantum dot self-assembly (0 to 1% compressive strain) the binding and activation energies on a strained Ge(001) surface increase and decrease, respectively, by 0.21 eV and 0.12 eV. For a growth temperature of 600 °C, these strain-dependencies give rise to a 16-fold increase in adatom density and a 5-fold decrease in adatom diffusivity in the region of compressive strain surrounding a Ge island with a characteristic size of 10 nm lying on top of a Si substrate covered by a Ge wetting layer.

Graphene surface induced specific self-assembly of poly(3-hexylthiophene) for nanohybrid optoelectronics: from first-principles calculation to experimental characterizations

Soft Matter ◽  
2013 ◽  
Vol 9 (22) ◽  
pp. 5355 ◽  
Author(s):  
Do Hwan Kim ◽  
Hyo Sug Lee ◽  
Hyeon-Jin Shin ◽  
Yoon-Su Bae ◽  
Kang-Hyuck Lee ◽  
...  
Keyword(s):  
First Principles ◽  
Self Assembly ◽  
First Principles Calculation ◽  
Graphene Surface

First-Principles Calculation of Lithium Adsorption and Diffusion on Silicene

2013 ◽  
Vol 30 (1) ◽  
pp. 017103 ◽  
Author(s):  
Juan Huang ◽  
Hong-Jin Chen ◽  
Mu-Sheng Wu ◽  
Gang Liu ◽  
Chu-Ying Ouyang ◽  
...  
Keyword(s):  
First Principles ◽  
First Principles Calculation ◽  
And Diffusion

Effect of strain on the magnetism of Fe-doped MoTe2 monolayer

2019 ◽  
Vol 33 (25) ◽  
pp. 1950304 ◽  
Author(s):  
Murong Zhang ◽  
Xiaojun Wang ◽  
Xin Wang ◽  
Ying Wang ◽  
Mingyan Wei ◽  
...  
Keyword(s):  
Density Of States ◽  
Magnetic Moment ◽  
First Principles ◽  
Tensile Strain ◽  
Compressive Strain ◽  
First Principles Calculation ◽  
Biaxial Strain

First-principles calculation has been performed to investigate the effect of strain on the magnetic moment of Fe-doped MoTe2 monolayer. Our results show that the Fe-doped MoTe2 monolayer is semiconductor with the magnetic moment of 2.037 [Formula: see text]. By analyzing the density of states, we find that the magnetic moment is mainly contributed by the Fe atom. When the biaxial strain is applied along the layer, the results show that the magnetic moment is almost unchanged when the compressive strain is under 5% and tensile strain is under 7%. However, as the strain increases, the magnetic moment decreases to almost zero with compressive strain larger than 7%, and the magnetic moment begins to increase with the tensile strain larger than 8%, which indicates the different effects of compressive strain and tensile strain on the magnetism of Fe-doped MoTe2.

scholarly journals Influence of Nickel Addition on the Stability, Trapping, and Diffusion Behaviour of Hydrogen in Vanadium: A First-Principles Investigation

2021 ◽  
Author(s):  
Jiayao Qin ◽  
Zhigao Liu ◽  
Wei Zhao ◽  
Dianhui Wang ◽  
Yanli Zhang ◽  
...  
Keyword(s):  
First Principles ◽  
Effective Means ◽  
Interstitial Site ◽  
First Principles Calculation ◽  
Hydrogen Energy ◽  
Ni Doping ◽  
Octahedral Interstitial Site ◽  
The Stability ◽  
And Diffusion ◽  
Diffusion Behaviour

Abstract Hydrogen embrittlement causes deterioration of materials used in hydrogen energy systems. Alloying is an effective means for overcoming this issue. In this study, the first-principles calculation method was used to investigate the effects of alloying Ni on the stability, dissolution, trapping, and diffusion behaviour of interstitial/vacancy H atoms in V. The calculated phonon spectra and solution energies of the vacancy/interstitial H atoms revealed that the V–Ni phase was dynamically and thermodynamically stable, and Ni addition could reduce the stability of V hydrides and improve their resistance to H embrittlement. H atoms in the interstitials and vacancies preferentially occupied the tetrahedral interstitial site (TIS) and octahedral interstitial site (OIS) with the lowest solution energies and diffused along the TIS → TIS and OIS → OIS paths with the minimum diffusion barrier energies. The trapping energy of the vacancy H atoms indicated that the addition of Ni could reduce the H trapping capability of the vacancies and suppress the retention of H in V. Detailed analysis of the calculated H diffusion barriers indicated that the presence of monovacancy defects blocked the diffusion of H atoms more than the presence of interstitials, and Ni doping did not enhance the H diffusion coefficient.

First-principles calculation of hydrogen adsorption and diffusion on Mn-doped Mg 2 Ni (010) surfaces

2017 ◽  
Vol 425 ◽  
pp. 148-155 ◽  
Author(s):  
Ziying Zhang ◽  
Jiarui Jin ◽  
Huizhen Zhang ◽  
Xiaoxiao Qi ◽  
Yang Bian ◽  
...  
Keyword(s):  
First Principles ◽  
Hydrogen Adsorption ◽  
First Principles Calculation ◽  
And Diffusion ◽  
Mn Doped

The performance of adsorption, dissociation and diffusion mechanism of hydrogen on the Ti-doped ZrCo(110) surface

2019 ◽  
Vol 21 (23) ◽  
pp. 12597-12605 ◽  
Author(s):  
Qingqing Wang ◽  
Xianggang Kong ◽  
Huilei Han ◽  
Ge Sang ◽  
Guanghui Zhang ◽  
...  
Keyword(s):  
First Principles ◽  
Diffusion Mechanism ◽  
First Principles Calculation ◽  
And Diffusion ◽  
Diffusion Of Hydrogen

Compared with pristine ZrCo(110), the adsorption, dissociation, and successive diffusion of hydrogen on the Ti-decorated ZrCo(110) have been investigated based on first-principles calculation.

Electronic properties of monolayer molybdenum dichalcogenides under strains

2015 ◽  
Vol 1726 ◽  
Author(s):  
J. Sugimoto ◽  
K. Shintani
Keyword(s):  
First Principles ◽  
Tensile Strain ◽  
Compressive Strain ◽  
Band Gaps ◽  
First Principles Calculation ◽  
Honeycomb Lattice ◽  
Biaxial Strain ◽  
Electronic Band ◽  
Zigzag Direction ◽  
Electronic Band Structures

ABSTRACTThe electronic band structures of monolayer molybdenum dichalcogenides, MoS2, MoSe2, and MoTe2 under either uniaxial or biaxial strain are calculated using first-principles calculation with the GW method. The imposed uniaxial strain is in the zigzag direction in the honeycomb lattice whereas the imposed biaxial strain is in the zigzag and armchair directions. It is found that the band gaps of these dichalcogenides almost linearly increase with the decrease of the magnitude of compressive strain, reach their maxima at some compressive strain, and then decrease almost linearly with the increase of tensile strain. It is also found their maximum band gaps are direct bandgaps.

First-Principles Study of the Self-Assembly Monolayer on Silicon (100) Surface

2012 ◽  
Vol 430-432 ◽  
pp. 28-31
Author(s):  
Li Qiu Shi ◽  
Feng Yu ◽  
Xiao Ping Hu ◽  
Xiao Wen Li ◽  
Tao Sun ◽  
...  
Keyword(s):  
Binding Energy ◽  
First Principles ◽  
Self Assembly ◽  
Density Functional ◽  
Covalent Bond ◽  
First Principles Calculation ◽  
Functional Theory ◽  
Aryldiazonium Salt ◽  
Before And After ◽  
The Stability

The first principles calculation based density functional theory has been employed to investigate the changes of energy, bonds length and bonds angle of aryldiazonium salt Self-assembly monolayer (SAMs) on silicon (100) surface. The steady structure and binding energy can be determined. It is shown that the partial bonds length and bonds angle have been changed obviously before and after self-assembly. The reduced energy of system is-101.95eV, i.e. binding energy, which is emitted energy of Si-C covalent bond coming into being, illuminates that the SAMs can be fabricated easily between aryldiazonium salt and Si (100) surface. The stability of system can be improved and SAMs can firmly stay on Si (100) surface.

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