A Molecular Dynamics Study for Dissociation of H2 Molecule on Pt(111) Surface

2012 ◽  
Vol 452-453 ◽  
pp. 1144-1148
Author(s):  
Takashi Tokumasu
Keyword(s):  
Molecular Dynamics ◽  
Atomic Motion ◽  
Embedded Atom Method ◽  
Dissociation Probability ◽  
Embedded Atom ◽  
Gas Molecule ◽  
H2 Molecule

The dissociation phenomena of H2 molecule on Pt(111) surface was simulated by Molecular Dynamics (MD) method and the effect of motion of the gas molecule or surface atoms on dissociation phenomena was analyzed in detail. The Embedded Atom Method (EAM) was used to model the interaction between an H2 molecule and Pt(111) surface. Using this potential, simulations of an H2 molecule impinging on a Pt(111) surface were performed and the characteristics of the collision were observed. Using MD data the dynamic dissociation probability were obtained and compared with the static dissociation probability to analyze the effect of atomic motion on dissociation phenomena.

Molecular Dynamics Simulation of Sputtering with Mmany-Body Interactions

1988 ◽  
Vol 100 ◽  
Author(s):  
Davy Y. Lo ◽  
Tom A. Tombrello ◽  
Mark H. Shapiro ◽  
Don E. Harrison
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Single Crystal ◽  
Low Energy ◽  
Dynamics Simulation ◽  
Embedded Atom Method ◽  
Many Body ◽  
Embedded Atom ◽  
Dynamics Simulations ◽  
Small Single Crystal

ABSTRACTMany-body forces obtained by the Embedded-Atom Method (EAM) [41 are incorporated into the description of low energy collisions and surface ejection processes in molecular dynamics simulations of sputtering from metal targets. Bombardments of small, single crystal Cu targets (400–500 atoms) in three different orientations ({100}, {110}, {111}) by 5 keV Ar+ ions have been simulated. The results are compared to simulations using purely pair-wise additive interactions. Significant differences in the spectra of ejected atoms are found.

Evaluation of Ni62Nb38 Bimetallic Glass Formation under Hydrostatically Pressurised Quenching

2020 ◽  
Vol 978 ◽  
pp. 436-445
Author(s):  
Mouparna Manna ◽  
Snehanshu Pal
Keyword(s):  
Molecular Dynamics ◽  
Md Simulation ◽  
Embedded Atom Method ◽  
Cooling Process ◽  
Forming Process ◽  
Glass Forming ◽  
Embedded Atom ◽  
Structural Evaluation ◽  
Fast Cooling ◽  
Compressive Pressure

In this present study, molecular dynamics (MD) simulation has been performed to investigate the influence of applied hydrostatic compressive and tensile pressure on glass forming process of Ni62Nb38 bimetallic glass using embedded atom method (EAM). During fast cooling (~10 K ps-1), tensile and compressive pressure has been applied having 0.001 GPa,0.01 GPa and 0.1 GPa magnitude. The glass transition temperature (Tg) for each pressurized (Tensile and Compressive nature) cooling case has been calculated and Tg is found to be dependent on both magnitude and nature of the pressure applied during cooling process.Voronoi cluster analysis has also been carried out to identify the structural evaluation during hydrostatically pressurised fast cooling process. In case of both hydrostatic tensile and compressive pressurised cooling processes, Tgincreases with the increase of pressure from 0.001 GPa to 0.1 GPa in magnitude.

Non-Equilibrium Molecular Dynamics Simulation of the Rapid Solidification of Metals

1989 ◽  
Vol 159 ◽  
Author(s):  
Cliff F. Richardson ◽  
Paulette Clancy
Keyword(s):  
Molecular Dynamics ◽  
Picosecond Laser ◽  
Simulation Method ◽  
Dynamics Simulation ◽  
Embedded Atom Method ◽  
Embedded Atom ◽  
Non Equilibrium Molecular Dynamics ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Non Equilibrium

ABSTRACTThe ultra-rapid melting and subsequent resolidification of Embedded Atom Method models of the fcc metals copper and gold are followed using a Non-Equilibrium Molecular Dynamics computer simulation method. Results for the resolidification of an exposed (100) face of copper at room temperature are in good agreement with recent experiments using a picosecond laser. At T = 0.5 Tm, the morphology of the solid/liquid interface is shown to be similar to a Lennard-Jones model. The morphology of the crystal-vapor interface at 92% of Tm shows a significant disordering of the topmost layers. Difficulties with the EAM model for gold are observed. Comparison of the Baskes et al. and Oh and Johnson embedding functions are discussed.

Structural Response of Metal Crystallite with BCC Lattice on Atomic Level under Nanoindentation

2013 ◽  
Vol 592-593 ◽  
pp. 55-58 ◽  
Author(s):  
Dmitrij Sergeevich Kryzhevich ◽  
Aleksandr Vyacheslavovich Korhuganov ◽  
Konstantin Petrovich Zolnikov ◽  
Sergei Grigorievich Psakhye
Keyword(s):  
Molecular Dynamics ◽  
Structural Response ◽  
Data Interpretation ◽  
High Accuracy ◽  
Atomic Level ◽  
Structural Defects ◽  
Embedded Atom Method ◽  
Free Surfaces ◽  
Embedded Atom ◽  
Bcc Lattice

Molecular dynamics investigation of metal crystallite with bcc lattice under nanoindentation was carried out. Potentials of interatomic interactions were calculated on the base of the approximation of the embedded atom method. The potentials chosen make it possible to describe with a high accuracy the elastic and surface properties of the simulated metal and energy parameters of defects, which is important for solution of the task posed in the work. For clarity and simpler indentation data interpretation, an extended cylindrical indenter was used in the investigation and loading was realized by its lateral surface. The simulated crystallite had a parallelepiped shape. The loaded plane of crystallite was modeled as a free surface while the positions of atoms in the opposite plane of crystallite were fixed along the indentation direction. Other planes of crystallite were simulated as free surfaces. The indenter velocity varied from 5 to 25 m/s in different calculations. The loading of the model crystallite was realized at 300 K. Influence of interfaces (free surfaces and grain boundaries) on peculiarities of plastic deformation nucleation and interactions of generated structural defects with interfaces in simulated crystallite under nanoindentation were investigated.

The Behavior of Copper Nanoparticle Chain Aggregates Under Strain – A Molecular Dynamics Approach

2003 ◽  
Vol 778 ◽  
Author(s):  
Adamos S. Dalis ◽  
Sheldon K. Friedlander
Keyword(s):  
Molecular Dynamics ◽  
Plastic Deformation ◽  
Embedded Atom Method ◽  
Sintering Process ◽  
Nano Composite ◽  
Embedded Atom ◽  
Reinforcing Fillers ◽  
Nanoparticle Aggregates ◽  
Chain Aggregates ◽  
Interface Sliding

AbstractNanoparticle chain aggregates (NCA) serve as reinforcing fillers that are combined with molecular polymers to produce nano-composite materials, e.g. carbon black in rubber. The reinforcing mechanism due to the incorporation of nanoparticle aggregates is not well understood. Molecular dynamics (MD) computer simulations are employed to investigate the behavior of nanoparticle chain aggregates under strain. The interaction potential used is that of Cu obtained with the embedded atom method (EAM). Three single-crystal Cu nanoparticles are placed in contact in two different configurations (linear and kinked) and the structures are initially relaxed with MD steps for 300 ps. We observe plastic deformation during the sintering process for very small particles (∼2.5 nm in diameter) at temperatures as low as 300 K. The relaxed configurations are then strained to the breaking point at strain rates in the order of 1 m/s. We identify mechanisms of strain accommodation that lead to nanoparticle plastic deformation and eventually fracture. The linear and the kinked configurations break at strains of 0.263 and 0.344 respectively, while the maximum stress is close to 4 GPa (strain rate: 0.625 m/s). Both structures fail at the low-angle grain boundaries developed during the sintering process, while the higher strain for fracture for the kinked configuration is associated with interface sliding not observed in the linear case.

Study on the structural transition of CoNi nanoclusters using molecular dynamics simulations

2018 ◽  
Vol 32 (11) ◽  
pp. 1850133
Author(s):  
J. H. Xia ◽  
Xue-Mei Gao
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Structural Transition ◽  
Correction Function ◽  
Embedded Atom Method ◽  
Embedded Atom ◽  
Analysis Technique ◽  
Dynamics Simulations ◽  
Embedded Atom Method Potential ◽  
Pair Analysis

In this work, the segregation and structural transitions of CoNi clusters, between 1500 and 300 K, have been investigated using molecular dynamics simulations with the embedded atom method potential. The radial distribution function was used to analyze the segregation during the cooling processes. It is found that Co atoms segregate to the inside and Ni atoms preferably to the surface during the cooling processes, the Co[Formula: see text]Ni[Formula: see text] cluster becomes a core–shell structure. We discuss the structural transition according to the pair-correction function and pair-analysis technique, and finally the liquid Co[Formula: see text]Ni[Formula: see text] crystallizes into the coexistence of hcp and fcc structure at 300 K. At the same time, it is found that the frozen structure of CoNi cluster is strongly related to the Co concentration.

Effects of Hydrogen on the Fracture Properties of Σ9 and Σ11 Tilt Boundaries in Nickel

1992 ◽  
Vol 278 ◽  
Author(s):  
J.E. Angelo ◽  
W.W. Gerberich ◽  
N.R. Moody ◽  
S.M. Foiles
Keyword(s):  
Molecular Dynamics ◽  
Monte Carlo ◽  
Fracture Stress ◽  
Equilibrium Distribution ◽  
Embedded Atom Method ◽  
Far Field ◽  
Fracture Properties ◽  
Embedded Atom ◽  
Tilt Boundaries ◽  
Dynamics Simulations

AbstractIn this study, the Embedded Atom Method is combined with Monte Carlo and molecular dynamics simulations to study the fracture properties of Σ9 and Σ11 tilt boundaries in nickel. The Monte Carlo simulations are used to simulate the exposure of the bicrystal to a hydrogen environment at 300° C. These simulations establish the equilibrium distribution of hydrogen at the boundaries as a function of far-field concentration. The effect of the hydrogen on the fracture process is then studied with molecular dynamics. It will be shown that the fracture stress of the Σ9 boundary is affected over a wider range of far-field concentrations than the Σ11 boundary, although the Σ11 boundary shows that catastrophic failure occurs when the sample is charged beyond a certain far-field concentration.

The effect of pressure on the elastic constants of Cu, Ag and Au: a molecular dynamics study

Open Physics ◽  
2006 ◽  
Vol 4 (4) ◽  
Author(s):  
Yasemin Çiftci ◽  
Kemal Çolakoğlu ◽  
Sefa Kazanç ◽  
SonerÖzgen
Keyword(s):  
Molecular Dynamics ◽  
Bulk Modulus ◽  
Elastic Constants ◽  
Md Simulation ◽  
Theoretical Calculations ◽  
Embedded Atom Method ◽  
Many Body ◽  
Effect Of Pressure ◽  
Embedded Atom ◽  
Function Expression

AbstractThis paper describes the effect of pressure on some the mechanical properties of transition metals Cu, Ag, and Au, such as elastic constants and bulk modulus. Using molecular dynamics (MD) simulation, the present study was carried out using the modified many-body Morse potential function expression in the framework of the Embedded Atom Method (EAM). The effect of pressure on equilibrium volume, elastic constants, and bulk modulus were determined, and found to be in agreement with other theoretical calculations and experimental data.

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