The Ehrlich-Schwoebel Effect for Vacancies: Low-Index Faces of Silver

MRS Proceedings ◽

10.1557/proc-648-p5.4 ◽

2000 ◽

Vol 648 ◽

Author(s):

Michael I. Haftel

Keyword(s):

Diffusion Barrier ◽

Activation Barrier ◽

Diffusion Barriers ◽

Step Edge ◽

Embedded Atom Method ◽

Vacancy Diffusion ◽

Exchange Diffusion ◽

Embedded Atom ◽

And Diffusion ◽

Step Edges

AbstractWe employ surface-embedded-atom-method potentials to investigate the diffusion barriers of vacancies diffusing over and near steps on the low index faces of silver. Barriers for vacancy terrace diffusion, diffusion over step-edges, and diffusion along step edges, including around corners, are calculated. Vacancies are significantly less mobile than adatoms and have large Ehrlich-Schwoebel (ES) barriers on all three faces. For Ag(100) the diffusion barrier for vacancies along step-edges is virtually the same (474 meV) as on the terrace. As in diffusion near the step edge, vacancies encounter a significant increase (213 meV) in the activation barrier when diffusing around the corner of a vacancy island (the corner analogue of the ES barrier), but the excess barrier around a kink all but disappears because exchange diffusion is favorable there. The consequences of the vacancy diffusion barriers on 3D pitting and on island diffusion and coarsening are discussed.

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Atomistic Simulation Study of Controlled Nanostructure Patterning

MRS Proceedings ◽

10.1557/proc-775-p9.27 ◽

2003 ◽

Vol 775 ◽

Cited By ~ 1

Author(s):

Byeongchan Lee ◽

Kyeongjae Cho

Keyword(s):

Diffusion Barrier ◽

Atomistic Simulation ◽

Degrees Of Freedom ◽

Embedded Atom Method ◽

Surface Kinetics ◽

Bulk Properties ◽

Embedded Atom ◽

Kinetics Of ◽

Dissociation Barrier ◽

Strain Dependent

AbstractWe investigate the surface kinetics of Pt using the extended embedded-atom method, an extension of the embedded-atom method with additional degrees of freedom to include the nonbulk data from lower-coordinated systems as well as the bulk properties. The surface energies of the clean Pt (111) and Pt (100) surfaces are found to be 0.13 eV and 0.147 eV respectively, in excellent agreement with experiment. The Pt on Pt (111) adatom diffusion barrier is found to be 0.38 eV and predicted to be strongly strain-dependent, indicating that, in the compressive domain, adatoms are unstable and the diffusion barrier is lower; the nucleation occurs in the tensile domain. In addition, the dissociation barrier from the dimer configuration is found to be 0.82 eV. Therefore, we expect that atoms, once coalesced, are unlikely to dissociate into single adatoms. This essentially tells that by changing the applied strain, we can control the patterning of nanostructures on the metal surface.

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Relaxation and diffusion barriers at step edges of Cu, Ag and Au homo- and heterogeneous systems: Case of (100) facet

International Journal of Materials Research (formerly Zeitschrift fuer Metallkunde) ◽

10.3139/146.111370 ◽

2016 ◽

Vol 107 (6) ◽

pp. 518-524 ◽

Cited By ~ 3

Author(s):

Mourad Benlattar ◽

Elyakout Elkoraychy ◽

Khalid Sbiaai ◽

M'hammed Mazroui ◽

Yahia Boughaleb ◽

...

Keyword(s):

Heterogeneous Systems ◽

Diffusion Barriers ◽

And Diffusion ◽

Step Edges

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Vacancy diffusion along twist grain boundaries in copper

Journal of Materials Research ◽

10.1557/jmr.1991.0001 ◽

1991 ◽

Vol 6 (1) ◽

pp. 1-4 ◽

Cited By ~ 25

Author(s):

Miki Nomura ◽

Sing-Yun Lee ◽

James B. Adams

Keyword(s):

Grain Boundaries ◽

Activation Energies ◽

Vacancy Formation ◽

Embedded Atom Method ◽

Vacancy Diffusion ◽

High Angle ◽

Self Diffusion ◽

Embedded Atom ◽

And Migration ◽

Formation Energies

Vacancy diffusion along two different high-angle twist grain boundaries (Σ5 and Σ13) was studied using the Embedded Atom Method (EAM). Vacancy formation energies in all the possible sites were calculated and found to be directly related to the degree of coincidence with the neighboring crystal planes. Optimal migration paths and migration energies were determined and found to be very low. The activation energies for self-diffusion at the boundaries were found to be less than half of the bulk value.

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Structural, Thermodynamics and Dynamics Properties of Fe-Ni Melts with Different EAM Models

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.750-752.579 ◽

2013 ◽

Vol 750-752 ◽

pp. 579-582

Author(s):

Teng Fang ◽

Li Wang ◽

Yu Qi

Keyword(s):

Diffusion Coefficients ◽

Md Simulation ◽

Embedded Atom Method ◽

Embedded Atom ◽

Ni Alloy ◽

Mixing Behavior ◽

Thermodynamics And Dynamics ◽

Experimental Values ◽

And Diffusion ◽

Good Agreement

Molecular dynamics (MD) simulation has been performed to explore the microstructure, thermodynamics and dynamics properties of liquid Fe-Ni alloy based upon two different embedded atom method (EAM) models. The calculated PCFs with two EAM models are good agreement with the experimental values. While the calculated Scc (q) of Bhatia-Thornton (B-T) structure factor (SF) shows different behavior: a sharp increasing and a small one at lower q from G. Bonnys model and Zhous model respectively. The mixing of enthalpy with G. Bonnys EAM is positive in the whole concentration range. While the different mixing behavior with a slightly negative mixing of enthalpy based on Zhous model, which is consistent with the experimental results, is observed. Density and diffusion coefficients of liquid Fe-Ni as a function of composition show the same tendency based on both G. Bonnys model and Zhous model. In this work, Fe-Ni melts show different mixing behavior based on the two different EAM models.

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Atomistic Simulation of the Self-Diffusion in Very Thin Cu (001) Film by Using MAEAM

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1015.37 ◽

2014 ◽

Vol 1015 ◽

pp. 37-41

Author(s):

Yan Ni Wen ◽

Xiao Bin Fang ◽

Xiao Fei Jia

Keyword(s):

Thin Film ◽

Atomistic Simulation ◽

Md Simulation ◽

Atomic Layer ◽

The Self ◽

Vacancy Formation ◽

Embedded Atom Method ◽

Self Diffusion ◽

Embedded Atom ◽

And Diffusion

The self-diffusion in very thin Cu (001) film that formed by 2~11 atomic layers have been studied by using modified analytic embedded atom method (MAEAM) and a molecular dynamic (MD) simulation. The vacancy formation is the most easily in of Cu (001) thin film formed by any layers. The vacancy formation energy 0.5054eV in of the Cu (001) thin film formed by layers is the highest in all the values in the ones that formed by layers. The vacancy in and 3 is easily migrated to layer, and the vacancy in is easily migrated in intra-layer, and the vacancy in is easily migrated to when the corresponding atomic layer is existed. The vacancy formation and diffusion will not be affected by the atomic layer when the Cu (001) thin film is formed by more than ten layers ().

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Influence of The Electrochemical Environment on Diffusion Processes Near Step and Island Edges: Ag(111) and Ag(100)

MRS Proceedings ◽

10.1557/proc-580-195 ◽

1999 ◽

Vol 580 ◽

Cited By ~ 3

Author(s):

Michael I. Haftel ◽

T. L. Einstein

Keyword(s):

Surface Charge ◽

Diffusion Processes ◽

Diffusion Barriers ◽

Step Edge ◽

Metallic Surfaces ◽

Embedded Atom ◽

Powerful Means ◽

Coarsening Dynamics ◽

Coarsening Kinetics ◽

Monotonically Decrease

AbstractThe electrochemical cell provides a potentially powerful means of altering morphology and islanding phenomena on metallic surfaces. Diffusion and attachment processes on terraces and near step and island edges are known to profoundly affect island sizes, shapes and coarsening kinetics. Using the surface-embedded-atom-model (SEAM) for describing metallic surfaces in the electrolytic environment, we calculate the dependence of the activation energies for the aforementioned diffusion processes on the deposited surface charge for the Ag(111) and Ag(100) surfaces in an electrolytic environment. While all these processes show some degree of dependence on the potential, the step-edge barrier and the edge diffusion processes are the most sensitive. Step-edge barriers increase (to over 1 eV) with large positive potential (0.85 V), while edge diffusion barriers monotonically decrease with positive surface charge on Ag(100) and Ag(111). We assess the effect these diffusion barriers have on island size/shapes and coarsening dynamics and discuss the implications on electrochemical tuning of islanding phenomena.

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Density functional calculations of the binding energies and adatom diffusion on strained AlN (0001) and GaN (0001) surfaces

MRS Proceedings ◽

10.1557/proc-1040-q06-02 ◽

2007 ◽

Vol 1040 ◽

Author(s):

Vibhu Jindal ◽

James Grandusky ◽

Neeraj Tripathi ◽

Mihir Tungare ◽

Fatemeh Shahedipour-Sandvik

Keyword(s):

Diffusion Barrier ◽

Potential Energy Surfaces ◽

Density Functional ◽

Density Functional Theory Calculations ◽

Diffusion Barriers ◽

Binding Energies ◽

Continuous Increase ◽

Diffusion Paths ◽

Energy Surfaces ◽

And Diffusion

AbstractDensity functional theory calculations were carried out to study the binding energies and diffusion barriers for various adatoms on AlN and GaN (0001) surfaces. The binding energies and potential energy surfaces were investigated for Al, Ga, and N adatoms on both Al (Ga) terminated and N terminated (0001) surfaces of AlN (GaN). Calculations for the diffusion paths and diffusion energy barriers for Al, Ga, and N adatoms on AlN and GaN were performed. It was found that the N adatom on N terminated AlN and GaN surfaces faces a high diffusion barrier due to strong N-N bond. The Al and Ga adatom on Al (Ga) terminated AlN (GaN) surfaces showed lower diffusion barriers due to the weak metallic bonds. However, the diffusion barrier for an Al adatom was always larger than that of a Ga adatom on any surface. The surfaces were also subjected to a hydrostatic compressive and tensile strain in the range of 0 to 5% to investigate the effect of strain on diffusion barriers. The diffusion energy barrier for N adatom on N terminated AlN and GaN surfaces decreased when the strain state was changed from tensile to compressive. In contrast, Al and Ga adatoms show continuous increase in diffusion barriers from tensile to compressively strained Al (Ga) terminated AlN (GaN) surfaces.

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An Atomistic Study of Surface Vacancy Diffusion

MRS Proceedings ◽

10.1557/proc-311-355 ◽

1993 ◽

Vol 311 ◽

Author(s):

L. Zhao ◽

R. Najafabadi ◽

D. J. Srolovtz

Keyword(s):

Film Growth ◽

Diffusion Mechanism ◽

Thin Film Growth ◽

Atomistic Simulations ◽

Embedded Atom Method ◽

Interatomic Potentials ◽

Vacancy Diffusion ◽

Embedded Atom ◽

Surface Vacancy ◽

Atomistic Study

ABSTRACTDiffusion of atoms and molecules on surfaces plays an important role in the growth of thin films. In the present study, the surface vacancy diffusion on Cu and Ni (100) and (111) planes is investigated via atomistic simulations. This investigation is performed using the Embedded Atom Method (EAM) interatomic potentials and the finite temperature properties are determined within the local harmonic and quasiharmonic frameworks. This study helps reveal fundamentals of surface vacancy diffusion in the thin film growth. Our results show that the vacancy diffusion is important on (100) surface but it is not the dominant diffusion mechanism on (111) plane.

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