Anisotropic vacancy-mediated phonon mode softening in Sm and Gd doped ceria

2018 ◽  
Vol 20 (15) ◽  
pp. 10048-10059 ◽  
Author(s):  
Dong-Hyuk Jung ◽  
Ji-Hwan Lee ◽  
Mehmet Emin Kilic ◽  
Aloysius Soon
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Oxygen Vacancies ◽  
Phonon Mode ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Mode Softening ◽  
Dynamics Simulations ◽  
And Diffusion ◽  
Diffusion Properties

The structural, vibrational, and diffusion properties of different ceria-based systems (including oxygen vacancies and rare-earth dopants (Sm or Gd)) have been examined using both first-principles density-functional theory calculations and finite-temperature molecular dynamics simulations.

Diffusion of Fluorine-Silicon Interstitial Complex in Crystalline Silicon

2005 ◽  
Vol 864 ◽  
Author(s):  
Scott A. Harrison ◽  
Thomas F. Edgar ◽  
Gyeong S. Hwang
Keyword(s):  
Density Functional Theory ◽  
Binding Energy ◽  
Charge State ◽  
First Principles ◽  
Density Functional ◽  
Positive Charge ◽  
Crystalline Silicon ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
And Diffusion

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.

scholarly journals Adsorption and diffusion characteristics of lithium on hydrogenated α- and β-silicene

2017 ◽  
Vol 8 ◽  
pp. 1742-1748
Author(s):  
Fadil Iyikanat ◽  
Ali Kandemir ◽  
Cihan Bacaksiz ◽  
Hasan Sahin
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Energy Surface ◽  
Diffusion Mechanism ◽  
Single Layer ◽  
Density Functional Theory Calculations ◽  
Binding Energies ◽  
Functional Theory ◽  
Diffusion Characteristics ◽  
And Diffusion

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.

scholarly journals In search of new reconstructions of (001) α-quartz surface: a first principles study

RSC Advances ◽  
2014 ◽  
Vol 4 (98) ◽  
pp. 55599-55603 ◽  
Author(s):  
Oleksandr I. Malyi ◽  
Vadym V. Kulish ◽  
Clas Persson
Keyword(s):  
Molecular Dynamics ◽  
Density Functional Theory ◽  
Molecular Dynamics Simulations ◽  
First Principles ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Quartz Surface ◽  
Functional Theory ◽  
First Principles Study ◽  
Dynamics Simulations

Using Born–Oppenheimer molecular dynamics simulations and “static” density functional theory calculations, reconstructions of the (001) α-quartz surface are studied in detail.

scholarly journals Adsorption and dissociation of H2O monomer on ceria(111): Density functional theory calculations

2020 ◽  
Vol 34 (24) ◽  
pp. 2050254 ◽  
Author(s):  
Shuangxi Wang ◽  
Ping Zhang
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Adsorption Properties ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Dynamics Simulations ◽  
Adsorption And Dissociation ◽  
Reduced Surface

The adsorption properties of isolated H2O molecule on stoichiometric and reduced ceria(111) surfaces are theoretically investigated by first-principles calculations and molecular dynamics simulations. We find that the most stable adsorption configurations form two hydrogen bonds between the adsorbate and substrate. The water molecule is very inert on the stoichiometric surface unless up to a high temperature of 600 K. For the reduced surface, we find that the oxygen vacancy enhances the interaction. Moreover, simulations at low temperature of 100 K confirm that it is facilitated for water to dissociate into H and OH species.

Graphene adlayer growth between nonepitaxial graphene and Ni(111) substrate: a promising theoretical scheme

2020 ◽  
Author(s):  
Lijuan Meng ◽  
Jinlian Lu ◽  
Yujie Bai ◽  
Lili Liu ◽  
Tang Jingyi ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Density Functional Theory ◽  
Chemical Vapor Deposition ◽  
Molecular Dynamics Simulations ◽  
Vapor Deposition ◽  
Density Functional ◽  
Chemical Vapor ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Dynamics Simulations

Understanding the fundamentals of chemical vapor deposition bilayer graphene growth is crucial for its synthesis. By employing density functional theory calculations and classical molecular dynamics simulations, we have investigated the...

scholarly journals Study on the adsorption selection of CH$$_4$$ on CuO (110) versus (111) surfaces: a density functional theory study

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Long Lin ◽  
Linwei Yao ◽  
Shaofei Li ◽  
Zhengguang Shi ◽  
Kun Xie ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Adsorption Capacity ◽  
Active Sites ◽  
Density Functional ◽  
Oxygen Vacancies ◽  
Density Functional Theory Calculations ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Strong Adsorption ◽  
Selection Of

AbstractFinding the active sites of suitable metal oxides is a key prerequisite for detecting CH$$_4$$ 4 . The purpose of the paper is to investigate the adsorption of CH$$_4$$ 4 on intrinsic and oxygen-vacancies CuO (111) and (110) surfaces using density functional theory calculations. The results show that CH$$_4$$ 4 has a strong adsorption energy of −0.370 to 0.391 eV at all site on the CuO (110) surface. The adsorption capacity of CH$$_4$$ 4 on CuO (111) surface is weak, ranging from −0.156 to −0.325 eV. In the surface containing oxygen vacancies, the adsorption capacity of CuO surface to CH$$_4$$ 4 is significantly stronger than that of intrinsic CuO surface. The results indicate that CuO (110) has strong adsorption and charge transfer capacity for CH$$_4$$ 4 , which may provide experimental guidance.

Understanding the advantage of hexagonal WO3 as an efficient photoanode for solar water splitting: a first-principles perspective

2016 ◽  
Vol 4 (29) ◽  
pp. 11498-11506 ◽  
Author(s):  
Taehun Lee ◽  
Yonghyuk Lee ◽  
Woosun Jang ◽  
Aloysius Soon
Keyword(s):  
Density Functional Theory ◽  
Band Gap ◽  
Water Splitting ◽  
Anode Material ◽  
First Principles ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Good Alternative ◽  
Functional Theory ◽  
Solar Water Splitting

Using first-principles density-functional theory calculations, we investigate the advantage of using h-WO3 (and its surfaces) over the larger band gap γ-WO3 phase for the anode in water splitting. We demonstrate that h-WO3 is a good alternative anode material for optimal water splitting efficiencies.

Mechanisms of Nitrogen Incorporation at 4H-SiC/SiO2 Interface during Nitric Oxide Passivation – A First Principles Study

2016 ◽  
Vol 858 ◽  
pp. 465-468 ◽  
Author(s):  
D.P. Ettisserry ◽  
Neil Goldsman ◽  
Akin Akturk ◽  
Aivars J. Lelis
Keyword(s):  
Nitric Oxide ◽  
Silicon Dioxide ◽  
First Principles ◽  
Density Functional ◽  
Oxygen Vacancies ◽  
Functional Theory ◽  
Power Mosfets ◽  
Voltage Instability ◽  
Nitrogen Incorporation ◽  
Effective Mobility

In this work, we investigate the behavior of Nitrogen atoms at 4H-Silicon Carbide (4H-SiC)/Silicon dioxide (SiO2) interface during nitric oxide passivation using ab-initio Density Functional Theory. Our calculations suggest different possible energetically favorable and competing mechanisms by which nitrogen atoms could a) incorporate themselves into the oxide, just above the 4H-SiC substrate, and b) substitute for carbon atoms at the 4H-SiC surface. We attribute the former process to cause increased threshold voltage instability (hole traps), and the latter to result in improved effective mobility through channel counter-doping, apart from removing interface traps in 4H-SiC power MOSFETs. These results support recent electrical and XPS measurements. Additionally, Nitric Oxide passivation is shown to energetically favor re-oxidation of the 4H-SiC surface accompanied by the generation of oxygen vacancies under the conditions considered in this work.

Probing the electronic structures of Con (n = 1–5) clusters on γ-Al2O3 surfaces using first-principles calculations

2017 ◽  
Vol 19 (5) ◽  
pp. 3679-3687 ◽  
Author(s):  
Tao Yang ◽  
Masahiro Ehara
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Electronic Structures ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
First Principles Calculations ◽  
Functional Theory

Using density functional theory calculations, we discussed the geometric and electronic structures and nucleation of small Co clusters on γ-Al2O3(100) and γ-Al2O3(110) surfaces.

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