Simulation of Pressure Effects on Glasses

1996 ◽  
Vol 455 ◽  
Author(s):  
Y. Kogure ◽  
M. Doyama
Keyword(s):  
Shear Stress ◽  
Pressure Effects ◽  
Dynamics Simulation ◽  
Mechanical Relaxation ◽  
Embedded Atom Method ◽  
Atomic Interaction ◽  
Atomic Configuration ◽  
Embedded Atom ◽  
Model Crystal ◽  
Embedded Atom Method Potential

ABSTRACTGlass transition and effects of pressure and shear stress on atomic configuration are investigated by means of molecular dynamics simulation. An embedded atom method potential is used for the atomic interaction. A model crystal for Cu is melted and quenched to realize the glass state. Atomic configuration in the glass is examined through the radial distribution function. External stress is applied and displacement of atoms is monitored to investigate the mechanism of mechanical relaxation. Larger displacement of atoms is observed under a shear stress.

Simulation of Stress Distribution and Mechanical Response of Metallic Glasses

1998 ◽  
Vol 554 ◽  
Author(s):  
Y. Kogure ◽  
M. Doyama
Keyword(s):  
Stress Distribution ◽  
Metallic Glasses ◽  
Mechanical Response ◽  
Local Density ◽  
Glassy State ◽  
Dynamics Simulation ◽  
Single Atom ◽  
Atomic Interaction ◽  
Embedded Atom ◽  
Embedded Atom Method Potential

AbstractMolecular dynamics simulation of the metallic glasses has been done. The embedded atom method potential function for copper is used to express the atomic interaction. The stress distribution in the glassy state is evaluated from specific volume occupied by single atom and local density in divided cells. The displacements of individual atom under the shear stress are calculated and the correlation between the displacements and the atomic volumes are investigated.

Glass Formation and Structural Study of Ti50Cu50 Alloy by Molecular Dynamics

2010 ◽  
Vol 638-642 ◽  
pp. 1665-1670 ◽  
Author(s):  
Jian Jun Pang ◽  
Ming Jen Tan ◽  
Anders W.E. Jarfors ◽  
P.D. Chuang
Keyword(s):  
Molecular Dynamics ◽  
Distribution Function ◽  
Metallic Glasses ◽  
Voronoi Tessellation ◽  
Supercooled Liquid ◽  
Dynamics Simulation ◽  
Embedded Atom Method ◽  
Atomic Configuration ◽  
Glass Forming ◽  
Embedded Atom

Ti-based metallic glasses (MGs) due to their relative low densities exhibit ultrahigh specific characteristics. In this article the glass-forming behavior and atomic structure of Ti50Cu50 MG were investigated through molecular dynamics simulation (MDS) using the general embedded-atom method (GEAM) potential. As observed experimentally, simulated Ti50Cu50 alloy undergoes three states on quenching: (i) equilibrium liquid; (ii) supercooled liquid and (iii) glassy solid. The atomic configuration of the glass was analysed based on the radial distribution function (RDF) and Voronoi tessellation (VT). It was found that there exist a variety of polyhedral units in Ti50Cu50 MG, where distorted icosohedral and bcc clusters are dominant.

MD Simulation of Dislocation Dynamics in Copper Nanoparticles

2009 ◽  
Vol 1224 ◽  
Author(s):  
Yoshiaki Kogure ◽  
Toshio Kogugi ◽  
Tadatoshi Nozaki ◽  
Masao Doyama
Keyword(s):  
Molecular Dynamics ◽  
Boundary Condition ◽  
Md Simulation ◽  
Dislocation Dynamics ◽  
Embedded Atom Method ◽  
Dislocation Configuration ◽  
Embedded Atom ◽  
Model Crystal ◽  
Embedded Atom Method Potential ◽  
Dynamics Method

AbstractAtomistic configuration and motion of dislocation have been simulated by means of molecular dynamics method. The embedded atom method potential for copper is adopted in the simulation. Model crystal is a rectangular solid containing about 140,000 atoms. An edge dislocation is introduced along [112] direction near the center of model crystal, and the system is relaxed. After the dislocation configuration is stabilized, a shear stress is applied and released. Wavy motion of dislocation is developed on the Peierls valleys when the free boundary condition is adopted. Motion of pinned dislocation is also simulated.

Simulation of Mechanical Response in Nanoparticles

2012 ◽  
Vol 184 ◽  
pp. 301-306 ◽  
Author(s):  
Yoshiaki Kogure ◽  
T. Kosugi ◽  
T. Nozaki
Keyword(s):  
Molecular Dynamics ◽  
Mechanical Response ◽  
The Other ◽  
Dynamics Simulation ◽  
Embedded Atom Method ◽  
Embedded Atom ◽  
Spherical Surfaces ◽  
Two Samples ◽  
Amorphous Structures ◽  
Embedded Atom Method Potential

Morphology and mechanical resonse of copper nanoparticles with defects have been simulated by means of molecular dynamics simulation. The embedded atom method potential for copper was used to express the interaction of atoms. Four types of model samples were prepared and about 37,000 atoms were contained in each sample. Two of them are cubic shape with {100} surfaces, in which vacancies or interstitials are introduced. The other two samples are once melted and solidified particles with nearly spherical surfaces. The atomic structure is controlled by cooling rate, and crystalline and amorphous structures are realized. Shear and tetragonal strains are applied to the samples and stress-strain relations for the samples are derived. Mechanical damping and internal friction were evaluated from the free decaying oscillations by releasing static strains.

scholarly journals The effect of electronic energy loss on the dynamics of thermal spikes in Cu

1991 ◽  
Vol 6 (3) ◽  
pp. 483-491 ◽  
Author(s):  
S. Prönnecke ◽  
A. Caro ◽  
M. Victoria ◽  
T. Diaz de la Rubia ◽  
M.W. Guinan
Keyword(s):  
Electronic Energy ◽  
Dynamics Simulation ◽  
Embedded Atom Method ◽  
Thermal Spike ◽  
Displacement Cascades ◽  
Embedded Atom ◽  
Ion Interactions ◽  
Electron Phonon Coupling ◽  
Coupling Time ◽  
Embedded Atom Method Potential

We present results of a molecular dynamics simulation study of the effect of electron-ion interactions on the dynamics of the thermal spike in Cu. Interatomic forces are described with a modified embedded atom method potential. We show that the electron-ion interaction acts to reduce the lifetime of the thermal spike and therefore the amount of atomic rearrangement that takes place in energetic displacement cascades in Cu. The results point toward the important effect that inelastic energy losses might have on the dynamics of displacement cascades in the subcascade energy regime where the lifetime of the thermal spike is expected to exceed the electron-phonon coupling time.

Interface Morphology of Metallic Multilayers by Means of Deposition Simulation

2006 ◽  
Vol 962 ◽  
Author(s):  
Kazuhito Shintani ◽  
Y. Kometani ◽  
T. Nakajima ◽  
Y. Yano
Keyword(s):  
Optimum Combination ◽  
Dynamics Simulation ◽  
Embedded Atom Method ◽  
Interface Morphology ◽  
Metallic Multilayers ◽  
Island Growth ◽  
Surface And Interface ◽  
Embedded Atom ◽  
Embedded Atom Method Potential ◽  
Deposition Simulation

ABSTRACTGrowth of a Co/Cu/Co multilayer is investigated by molecular-dynamics simulation. The interactions between Co and Cu atoms are calculated in terms of the generic-embedded atom method potential. It is confirmed that two-dimensional island growth of Cu atoms on the Co substrate occurs in the simulations. The roughnesses of the surface and the interface are evaluated by means of the standard deviations of the heights of the surface and interface atoms. Intermixing atoms between the layers are also counted. We conclude that there exists an optimum combination of the incident energies of deposited Cu and Co atoms which minimizes both the roughness and intermixing of the interface.

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.

Simulation of Dislocation Relaxation in FCC Metals

2006 ◽  
Vol 978 ◽  
Author(s):  
Yoshiaki Kogure ◽  
Kei Sakieda ◽  
Toshio Kosugi ◽  
Tadatoshi Nozaki
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Potential Energy ◽  
Edge Dislocation ◽  
Dislocation Motion ◽  
Dynamics Simulation ◽  
Embedded Atom Method ◽  
Fcc Metals ◽  
Embedded Atom ◽  
Embedded Atom Method Potential

Abstract Motion of edge dislocation in copper crystals is investigated by means of molecular dynamics simulation. The embedded atom method potential was used in the simulation. Configuration and motion of dislocations are graphically demonstrated in 3-dimentional model. Change of mean potential energy during the dislocation motion is also investigated.

An embedded-atom method interatomic potential for Pd–H alloys

2008 ◽  
Vol 23 (3) ◽  
pp. 704-718 ◽  
Author(s):  
X.W. Zhou ◽  
J.A. Zimmerman ◽  
B.M. Wong ◽  
J.J. Hoyt
Keyword(s):  
Computational Models ◽  
Mechanical Response ◽  
Hydrogen Diffusion ◽  
Interatomic Potential ◽  
Diffusion Mechanism ◽  
Miscibility Gap ◽  
Embedded Atom Method ◽  
Embedded Atom ◽  
Formidable Challenge ◽  
Embedded Atom Method Potential

Palladium hydrides have important applications. However, the complex Pd–H alloy system presents a formidable challenge to developing accurate computational models. In particular, the separation of a Pd–H system to dilute (α) and concentrated (β) phases is a central phenomenon, but the capability of interatomic potentials to display this phase miscibility gap has been lacking. We have extended an existing palladium embedded-atom method potential to construct a new Pd–H embedded-atom method potential by normalizing the elemental embedding energy and electron density functions. The developed Pd–H potential reasonably well predicts the lattice constants, cohesive energies, and elastic constants for palladium, hydrogen, and PdHx phases with a variety of compositions. It ensures the correct hydrogen interstitial sites within the hydrides and predicts the phase miscibility gap. Preliminary molecular dynamics simulations using this potential show the correct phase stability, hydrogen diffusion mechanism, and mechanical response of the Pd–H system.

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