Crystal-melt interface stresses: Atomistic simulation calculations for a Lennard-Jones binary alloy, Stillinger-Weber Si, and embedded atom method Ni

2007 ◽  
Vol 75 (6) ◽  
Author(s):  
C. A. Becker ◽  
J. J. Hoyt ◽  
D. Buta ◽  
M. Asta
Keyword(s):  
Binary Alloy ◽  
Atomistic Simulation ◽  
Embedded Atom Method ◽  
Lennard Jones ◽  
Embedded Atom

Atomistic Simulation Study of Controlled Nanostructure Patterning

2003 ◽  
Vol 775 ◽  
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.

scholarly journals Fabrication of Magnesium-Aluminum Composites under High-Pressure Torsion: Atomistic Simulation

2021 ◽  
Vol 11 (15) ◽  
pp. 6801
Author(s):  
Polina Viktorovna Polyakova ◽  
Julia Alexandrovna Pukhacheva ◽  
Stepan Aleksandrovich Shcherbinin ◽  
Julia Aidarovna Baimova ◽  
Radik Rafikovich Mulyukov
Keyword(s):  
Atomistic Simulation ◽  
High Pressure Torsion ◽  
Tensile Tests ◽  
Temperature Treatment ◽  
Embedded Atom Method ◽  
Interface Bonding ◽  
Embedded Atom ◽  
Interlayer Region ◽  
Kinetics Of ◽  
Loading Scheme

The aluminum–magnesium (Al–Mg) composite materials possess a large potential value in practical application due to their excellent properties. Molecular dynamics with the embedded atom method potentials is applied to study Al–Mg interface bonding during deformation-temperature treatment. The study of fabrication techniques to obtain composites with improved mechanical properties, and dynamics and kinetics of atom mixture are of high importance. The loading scheme used in the present work is the simplification of the scenario, experimentally observed previously to obtain Al–Cu and Al–Nb composites. It is shown that shear strain has a crucial role in the mixture process. The results indicated that the symmetrical atomic movement occurred in the Mg–Al interface during deformation. Tensile tests showed that fracture occurred in the Mg part of the final composite sample, which means that the interlayer region where the mixing of Mg, and Al atoms observed is much stronger than the pure Mg part.

Embedded atom method potentials for Ce-Ni binary alloy

2018 ◽  
Vol 150 ◽  
pp. 1-8 ◽  
Author(s):  
Yawei Lei ◽  
Xiaorui Sun ◽  
Rulong Zhou ◽  
Bo Zhang
Keyword(s):  
Binary Alloy ◽  
Embedded Atom Method ◽  
Embedded Atom

Stucture of 1/2 Dislocations In γ-Tial by High Resolution Tem and Embedded Atom Method Modelling

1994 ◽  
Vol 364 ◽  
Author(s):  
J. P. Simmons ◽  
M. J. Mills ◽  
S. I. Rao
Keyword(s):  
High Resolution ◽  
Atomistic Simulation ◽  
Embedded Atom Method ◽  
Simulation Methods ◽  
Embedded Atom ◽  
A Value ◽  
High Resolution Tem ◽  
Atomistic Calculations ◽  
Range Of Values ◽  
Limit Estimate

AbstractHigh Resolution TEM (HRTEM) observations of a dislocation in γ-TiAl are compared directly with atomistic calculations of dislocation structures performed with atomistic potentials in order to obtain an estimate of the Complex Stacking Fault Energy (γcsf). A value of between 470 and 620 mJ/M2 was obtained. HRTEM observations are presented of a Ti-52AI sample, containing a dislocation with Burgers vector 1/2<110> and 60° line orientation. This image is matched against images simulated from the outputs of Embedded Atom Method (EAM) simulations, using potentials that were fit to bulk γ-TiAl properties. Two atomistic simulation methods were employed in order to give the range of values for γcsf. In the first of these methods, three EAM potentials were used to simulate the stress-free core structure. These were fit so as to produce three different values of γcsf, all other properties being roughly the same as the literature values for γ-TiAI. All of these potentials produced cores that were more extended than the experimental observation. Thus a value of 470 mJ/M2, being the highest value of γcsf obtainable for the EAM potentials, is reported as a low limit estimate of γcsf for γ-TiAl. An upper limit estimate of the value of γcsf was obtained by applying an external ‘Escaig’ stress that forced the Shockley partials to further constrict, simulating the effect of an increase in γcsf, The preliminary value calculated from this procedure was 620 mJ/M2.

scholarly journals Molecular Dynamics Simulations of Ionized Cluster Beam Deposition

1989 ◽  
Vol 157 ◽  
Author(s):  
Horngming Hsieh ◽  
R.S. Averback ◽  
R. Benedek
Keyword(s):  
Point Defects ◽  
Embedded Atom Method ◽  
Cluster Beam ◽  
Physical Mechanisms ◽  
Lennard Jones ◽  
Embedded Atom ◽  
Cluster Energy ◽  
Dynamics Simulations ◽  
Cluster Beam Deposition ◽  
Beam Deposition

ABSTRACTFully dynamical computer simulations have been used to study the physical mechanisms of ionized cluster beam deposition. Clusters containing 92 atoms were directed at <001> surfaces with energies per cluster atom ranging from one sixth to three times the cohesive energy of the target. Simulation events employed either Lennard-Jones or Embedded Atom Method potentials. The atoms in the cluster appear to undergo local melting on impact with the substrate. Higher cluster energy increases the spreading of cluster atoms on the substrate and improves epitaxy, but it also increases interdiffusion and produces point defects.

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

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 ().

Reconstruction of grain boundaries in copper and gold by simulation

1994 ◽  
Vol 9 (3) ◽  
pp. 582-591 ◽  
Author(s):  
S.R. Phillpot
Keyword(s):  
Physical Properties ◽  
Grain Boundaries ◽  
Embedded Atom Method ◽  
Lennard Jones Potential ◽  
High Angle ◽  
Jones Potential ◽  
Lennard Jones ◽  
Embedded Atom ◽  
Embedded Atom Method Potential ◽  
Grand Canonical

The reconstructions of high-angle twist grain boundaries on the four densest atomic planes in fcc copper, as described by a Lennard-Jones potential, and gold, as described by an embedded-atom-method potential, are investigated using the recently developed method of grand-canonical simulated quenching. It is found that the grain boundaries on the widely spaced (111) and (100) planes do not reconstruct, while those on the less widely spaced (110) and (113) planes do reconstruct. The effect that reconstruction can have on the physical properties of an interfacial system is illustrated by comparing the elastic properties and ideal cleavage energies of reconstructed grain boundaries with those of corresponding unreconstructed grain boundaries.

Computer Simulation of Helium Effects in Plutonium During the Aging Process of Self-Radiation Damage

2012 ◽  
Vol 11 (4) ◽  
pp. 1205-1225 ◽  
Author(s):  
Bingyun Ao ◽  
Piheng Chen ◽  
Peng Shi ◽  
Xiaolin Wang ◽  
Wangyu Hu ◽  
...  
Keyword(s):  
Radiation Damage ◽  
Radioactive Decay ◽  
Pair Potential ◽  
Embedded Atom Method ◽  
Release Channel ◽  
Lennard Jones ◽  
Embedded Atom ◽  
Initial Nucleation ◽  
Modified Embedded Atom Method ◽  
He Atom

AbstractDue to α radioactive decay Pu is vulnerable to aging. The behavior of He in Pu is the foundation for understanding Pu self-radiation damage aging. Molecular dynamics technique is performed to investigate the behavior of defects, the interaction between He and defects, the processes of initial nucleation and growth of He bubble and the dependence of He bubble on the macroscopical properties of Pu. Modified embedded atom method, Morse pair potential and the Lennard-Jones pair potential are used for describing the interactions of Pu-Pu, Pu-He and He-He, respectively. The main calculated results show that He atoms can combine with vacancies to form Hevacancy cluster (i.e., the precursor of He bubble) during the process of self-radiation as a result of high binding energy of an interstitial He atom to vacancy; He bubble’s growth can be dominated by the mechanism of punching out of dislocation loop; the swelling induced by He bubble is very small; grain boundaries give rise to an energetically more favorable zone for the interstitial He atom and self-interstitial atom accumulation than for vacancy accumulation; the process of He release can be identified as the formation of release channel induced by the cracking of He bubble and surface structure.

Is there a Limit to Nanoscale Mechanical Machining?

2013 ◽  
Vol 581 ◽  
pp. 316-321
Author(s):  
Akinjide O. Oluwajobi ◽  
Xun Chen
Keyword(s):  
Material Removal ◽  
Md Simulation ◽  
Depth Of Cut ◽  
Embedded Atom Method ◽  
Guiding Principle ◽  
Lennard Jones ◽  
Embedded Atom ◽  
Removal Processes ◽  
Mechanical Machining ◽  
Eam Potential

The Moores law which predicts that the number of transistors which can be integrated on the computer chip will double every 24 months and which has been the guiding principle for the advancement of the computer industry, is gradually reaching its limit. This is due to the limitations imposed by the laws of physics. Similarly, in the machining sector, Taniguchi predicted an increasing achievable machining precision as a function of time in the 1980s and this prediction is still on course. The question also is, is there a limit to machining and to material removal processes; and how far can this prediction be sustained? In this paper, the molecular dynamics (MD) simulation was employed to investigate this limit in the nanomachining of a copper workpiece with a diamond tool. The variation of the depth of cut used was from 0.01nm to 0.5nm. The Embedded Atom Method (EAM) potential was used for the copper-copper interactions in the workpiece; the Lennard-Jones (LJ) potential was used for the copper-carbon (workpiece-tool interface) interactions and the tool (carbon-carbon interactions) was modelled as deformable by using the Tersoff potential. It was observed from the simulation results that no material removal occurred between 0.01nm 0.25nm depth. At the depth of cut of 0.3nm, a layer of atoms appears to be removed or ploughed through by the tool. At a depth of cut less than 0.3nm, the other only phenomenon observed was the squeezing of the atom. The 0.3nm depth of cut is around the diameter of the workpiece-copper atom. So, it may be suggested that the limit of machining may be the removal of the atom of the workpiece.

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