Molecular Dynamics Simulations of High Energy Cascades in Iron

1994 ◽  
Vol 373 ◽  
Author(s):  
Roger E. Stoller
Keyword(s):  
Molecular Dynamics ◽  
Three Dimensional ◽  
High Energy ◽  
Dynamics Simulation ◽  
Method Of Molecular Dynamics ◽  
Energy Cascades ◽  
Iron Based ◽  
The Many ◽  
Property Changes ◽  
Dynamics Simulations

AbstractA series of high-energy, up to 20 keV, displacement cascades in iron have been investigated for times up to 200 ps at 100 K using the method of molecular dynamics simulation. Thesimulations were carried out using the MOLDY code and a modified version of the many-bodyinteratomic potential developed by Finnis and Sinclair. The paper focuses on those results obtained at the highest energies, 10 and 20 keV. The results indicate that the fraction of the Frenkel pairs surviving in-cascade recombination remains fairly high in iron and that the fraction of the surviving point defects that cluster is lower than in materials such as copper. In particular, vacancy clustering appears to be inhibited in iron. Some of the interstitial clusters were observed to exhibit an unexpectedly complex, three-dimensional morphology. The observations are discussed in terms of their relevance to microstructural evolution and mechanical property changes in irradiated iron-based alloys.

Molecular Dynamics Simulations of Hot Electrons and Lattice Relaxation in Realistic Cascade Volumes

1992 ◽  
Vol 278 ◽  
Author(s):  
A.M. Mazzone
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Molecular Dynamics Simulations ◽  
Classical Mechanics ◽  
Lattice Relaxation ◽  
Simulation Method ◽  
High Energy ◽  
Hot Electrons ◽  
Dynamics Simulation ◽  
Dynamics Simulations

AbstractThis work presents a molecular dynamics simulation method designed to describe the processes of electron and lattice relaxation taking place in typical cascade volumes formed by high-energy implants. The simulation method is based on classical mechanics and includes the motions of electrons and nuclei. The results are in agreement with experiments.

Deformation and Fracture of Metallic Nanowires

2016 ◽  
Vol 258 ◽  
pp. 277-280 ◽  
Author(s):  
Mohamed Mahmud Aish ◽  
Mikhail D. Starostenkov
Keyword(s):  
Molecular Dynamics ◽  
Interatomic Potential ◽  
Tight Binding ◽  
Three Dimensional ◽  
Dynamics Simulation ◽  
Metallic Nanowires ◽  
Many Body ◽  
Binding Model ◽  
Deformation And Fracture ◽  
Dynamics Simulations

A many-body interatomic potential for metallic nanowires within the second-moment approximation of the tight-binding model (the Cleri-Rosato potential) was employed to carry out three dimensional molecular dynamics simulations. Molecular dynamics simulation results for metallic nanowires at various temperature are presented. The stress–time and stress length curves for nanowires are simulated. The breaking and yield stress of nanowires are dependent on the Volume and temperature. The necking, Plastic deformation, slipping domain, twins, clusters, microspores and break-up phenomena of nanowire are demonstrated. Stress decreases with increasing nanowire volume and temperature. The final breaking position occurs at the central part of the nanowire when it is short, as the nanowire length increases the breaking position gradually shifts to the ends.

scholarly journals Molecular Dynamics Simulation of Cascade Damage in Gold

1996 ◽  
Vol 439 ◽  
Author(s):  
E. Alonso ◽  
M. J. Caturla ◽  
M. Tang ◽  
H. Huang ◽  
T. Diaz de ia Rubia
Keyword(s):  
Molecular Dynamics ◽  
High Pressures ◽  
High Energy ◽  
Dynamics Simulation ◽  
Embedded Atom Method ◽  
Embedded Atom ◽  
Energy Cascades ◽  
Modified Embedded Atom Method ◽  
Embedded Atom Method Potential ◽  
Cascade Damage

AbstractHigh-energy cascades have been simulated in gold using molecular dynamics with a modified embedded atom method potential. The results show that both vacancy and interstitial clusters form with high probability as a result of intracascade processes. The formation of clusters has been interpreted in terms of the high pressures generated in the core of the cascade during the early stages. We provide evidence that correlation between interstitial and vacancy clustering exists.

scholarly journals Molecular Dynamics Simulation of Impurities in Nanocrystalline Diamond Grain Boundaries

1999 ◽  
Vol 593 ◽  
Author(s):  
Michael Sternberg ◽  
Peter Zapoll ◽  
Thomas Frauenheim ◽  
Dieter M. Gruen ◽  
Larry A. Curtiss
Keyword(s):  
Molecular Dynamics ◽  
Grain Boundaries ◽  
Density Functional ◽  
Tight Binding ◽  
High Energy ◽  
Nanocrystalline Diamond ◽  
Dynamics Simulation ◽  
Si Substrates ◽  
Dynamics Simulations ◽  
Diamond Grain

ABSTRACTNanocrystalline diamond films grown on Si substrates at 800°C from hydrogen-poorplasmas have a number of highly desirable mechanical and electronic properties. Impurities were found by SIMS measurements to be uniformly distributed throughout the thickness of the films at a level of 1017–1018 cm−3. It is likely that the impurities are located at the grain boundaries, which play a crucial role in controlling important characteristics of the films, such as electrical conductivity and electron emission. Density-functional based tight-binding (DFTB) molecular dynamics simulations were performed for diamond high-energy high-angle (100) twist grain boundaries with impurities such as N, Si and H

scholarly journals A Molecular Dynamics Simulation Study of Defect Production in Vanadium

1995 ◽  
Vol 396 ◽  
Author(s):  
K. Morishita ◽  
T. Diaz De La Rubia
Keyword(s):  
Molecular Dynamics ◽  
Interatomic Potential ◽  
Cluster Formation ◽  
High Energy ◽  
Dynamics Simulation ◽  
Minimum Threshold ◽  
Defect Production ◽  
Dynamics Simulations ◽  
Threshold Energies ◽  
Experimental Melting

AbstractWe performed molecular dynamics simulations to investigate the process of defect production in pure vanadium. The interaction of atoms was described by the EAM interatomic potential modified at short range to merge smoothly with the universal potential for description of the high energy recoils in cascades. The melting point of this EAM model of vanadium was found to be consistent with the experimental melting temperature. The threshold energies of displacement events in the model system are also consistent with experimental minimum threshold in vanadium, and its average was found to be 44 eV. We evaluated the efficiencies of defect production in the displacement events initiated by recoils with kinetic energy up to 5 keV, and found that the probability of cluster formation is smaller than that of simulated events in fee metals reported in the literature.

Multicanonical Molecular Dynamics Simulation Study of the Liquid-Solid and Solid-Solid Transitions in Lennard-Jones Clusters

2011 ◽  
Author(s):  
Toshihiro Kaneko ◽  
Kenji Yasuoka ◽  
Ayori Mitsutake ◽  
Xiao Cheng Zeng
Keyword(s):  
Molecular Dynamics ◽  
Heat Capacity ◽  
Transition Temperature ◽  
Peak Position ◽  
Temperature Curve ◽  
Dynamics Simulation ◽  
Lennard Jones ◽  
Dynamics Simulations ◽  
First Time ◽  
Good Agreement

Multicanonical molecular dynamics simulations are applied, for the first time, to study the liquid-solid and solid-solid transitions in Lennard-Jones (LJ) clusters. The transition temperatures are estimated based on the peak position in the heat capacity versus temperature curve. For LJ31, LJ58 and LJ98, our results on the solid-solid transition temperature are in good agreement with previous ones. For LJ309, the predicted liquid-solid transition temperature is also in agreement with previous result.

scholarly journals Reactive molecular dynamics simulation of the high-temperature pyrolysis of 2,2′,2′′,4,4′,4′′,6,6′,6′′-nonanitro-1,1′:3′,1′′-terphenyl (NONA)

RSC Advances ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 5507-5515
Author(s):  
Liang Song ◽  
Feng-Qi Zhao ◽  
Si-Yu Xu ◽  
Xue-Hai Ju
Keyword(s):  
Molecular Dynamics ◽  
High Temperature ◽  
Molecular Dynamics Simulation ◽  
Molecular Dynamics Simulations ◽  
Dynamics Simulation ◽  
Reactive Molecular Dynamics ◽  
Ring Compounds ◽  
Fused Ring ◽  
Dynamics Simulations

The bimolecular and fused ring compounds are found in the high-temperature pyrolysis of NONA using ReaxFF molecular dynamics simulations.

Molecular Dynamics Simulation Study of Lecithin Inhibiting Hydrate-Dissociation

2017 ◽  
Vol 890 ◽  
pp. 252-259
Author(s):  
Le Wang ◽  
Guan Cheng Jiang ◽  
Xin Lin ◽  
Xian Min Zhang ◽  
Qi Hui Jiang
Keyword(s):  
Molecular Dynamics ◽  
Water Movement ◽  
Simulation Analysis ◽  
Mass Density ◽  
Dynamics Simulation ◽  
Dissociation Process ◽  
Hydrate Dissociation ◽  
Hydrocarbon Chains ◽  
Dynamics Simulations ◽  
Mass Density Profile

Molecular dynamics simulations are used to study the dissociation inhibiting mechanism of lecithin for structure I hydrates. Adsorption characteristics of lecithin and PVP (poly (N-vinylpyrrolidine)) on the hydrate surfaces were performed in the NVT ensemble at temperatures of 277K and the hydrate dissociation process were simulated in the NPT ensemble at same temperature. The results show that hydrate surfaces with lecithin is more stable than the ones with PVP for the lower potential energy. The conformation of lecithin changes constantly after the balanced state is reached while the PVP molecular dose not. Lecithin molecule has interaction with lecithin nearby and hydrocarbon-chains of lecithin molecules will form a network to prevent the diffusion of water and methane molecules, which will narrow the available space for hydrate methane and water movement. Compared with PVP-hydrate simulation, analysis results (snapshots and mass density profile) of the dissociation simulations show that lecithin-hydrate dissociates more slowly.

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