MOLECULAR DYNAMICS SIMULATION STUDY OF ATOMIC SEGREGATION OF (PdPt)147 DURING THE HEATING PROCESS

2012 ◽  
Vol 26 (08) ◽  
pp. 1250051 ◽  
Author(s):  
X. Y. XIAO ◽  
Z. F. CHENG ◽  
J. H. XIA
Keyword(s):  
Molecular Dynamics ◽  
Melting Process ◽  
Dynamics Simulation ◽  
Heating Process ◽  
Embedded Atom Method ◽  
Bimetallic Cluster ◽  
Embedded Atom ◽  
Atomic Segregation ◽  
Segregation Process ◽  
Alloy Concentration

Research on the influence of alloy concentration and distribution on bimetallic cluster plays a key role in exploring new structural material. This paper studies the melting process of icosahedral bimetallic cluster (PdPt)147 with different Pt concentrations and different atomic distributions by using molecular dynamics with an embedded atom method. The results indicate that the mixed Pd–Pt cluster shows an irregular phenomenon between 580 and 630 K, i.e. the atomic energy decreases with the increase of temperature. This is because the surface energy of Pd is lower than that of Pt; the decreased energy due to Pd atomic segregation is larger than the increased energy due to heating during the segregation process. In addition, the temperature of Pd atomic segregation is strongly related to Pt concentration. This leads to that Pd atoms prefer to remain on the surface even after the cluster melted.

EFFECT OF Cu ATOMIC SEGREGATION ON THE FROZEN STRUCTURES OF Co–Cu BIMETALLIC CLUSTERS

NANO ◽  
2012 ◽  
Vol 07 (06) ◽  
pp. 1250047 ◽  
Author(s):  
YINGJIE ZHANG ◽  
YONGQIANG LI ◽  
XUYANG XIAO ◽  
YUNHUI YAN
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Energy State ◽  
Excess Energy ◽  
Dynamics Simulation ◽  
Bimetallic Clusters ◽  
Embedded Atom Method ◽  
Truncated Octahedron ◽  
Embedded Atom ◽  
Atomic Segregation

Atomic segregation in bimetallic clusters can influence the surface constituent and be used to affect the frozen structure. In this study, molecular dynamics simulation with an embedded atom method was used to study the frozen structures of (CoCu)561 clusters with different Co contents. It is found that the clusters can freeze to form icosahedron, truncated octahedron, decahedron or hcp with the change of Co contents. In these geometries, the structure of the lowest energy state is hcp, then in turn decahedron and truncated octahedron. The frozen structures are related to the release of excess energy, while the released excess energy was affected by the amount of segregated Cu atoms. This means that the atomic segregation can be used to tune the structures of bimetallic clusters.

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.

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.

Molecular Dynamics Simulation of Compressive Mechanical Behavior of Nanocrystalline Fe

2005 ◽  
Vol 475-479 ◽  
pp. 3291-3294
Author(s):  
Shi Fang Xiao ◽  
Yu Hu Wang
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Plastic Deformation ◽  
Deformation Process ◽  
Dynamics Simulation ◽  
Embedded Atom Method ◽  
Deformation Region ◽  
Embedded Atom ◽  
Boundary Atom ◽  
Strain Strengthening

The uniaxial compressive mechanical properties of nanocrystalline Fe are simulated with a molecular dynamics technique and the analytical embedded-atom method. An asymmetrical mechanical phenomenon between tensile and compressive process is found, and the yield stress and flow stress in compression are higher than those in tension simulations. The compressive deformation process can be described as three characteristic regions: quasi-elastic deformation, plastic flowing deformation, and strain strengthening. During the plastic flowing deformation region, the material shows very good compressive ductibility. The plastic deformation is mainly dominated by the grain boundary atom slide.

Calculation of Material Properties Using Molecular Dynamics Simulation

2007 ◽  
Author(s):  
Y. H. Park ◽  
J. Tang
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Melting Point ◽  
Material Properties ◽  
Morse Potential ◽  
Formation Energy ◽  
Dynamics Simulation ◽  
Embedded Atom Method ◽  
Embedded Atom ◽  
Dynamics Method

This paper describes the calculation of material properties of copper (Cu) using the molecular dynamics method. Vacancy formation energy, bulk modulus, surface energy and melting point are calculated using different potentials such as the Morse potential and Embedded Atom Method (EAM). Results obtained from different potentials are discussed and compared with experimental results.

Molecular Dynamics Simulation of Liquid Cu-Ni Alloy Using Embedded Atom Method

2013 ◽  
Vol 643 ◽  
pp. 116-119
Author(s):  
Teng Fang ◽  
Li Wang ◽  
Yu Qi
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Dynamics Simulation ◽  
Mixing Enthalpy ◽  
Embedded Atom Method ◽  
Liquid Density ◽  
Embedded Atom ◽  
Ni Alloy ◽  
Thermodynamics And Dynamics ◽  
Calculated Liquid

Molecular dynamics simulation has been performed to explore the thermodynamics and dynamics properties of liquid Cu-Ni alloy based upon developed embedded atom methods (EAM), namely due to G. Bonny. The calculated liquid density shows that the potential underestimates the measured atomic density for Ni-rich composition. The calculated mixing enthalpy predicts the potential underestimates the mixing enthalpy when the concentration of Ni is increased beyond roughly 30 at. %. We make a conclusion from the fact that the G. Bonny’s model is not full perfect in describing the density and mixing enthalpy of Cu-Ni melts at the Ni-rich composition.

Molecular dynamics simulation of surface morphology during homoepitaxial growth of Copper

2019 ◽  
Vol 87 (3) ◽  
pp. 31301 ◽  
Author(s):  
Hicham El Azrak ◽  
Abdessamad Hassani ◽  
Abdelhadi Makan ◽  
Fouad Eddiai ◽  
Khalid Sbiaai ◽  
...  
Keyword(s):  
Thin Film ◽  
Molecular Dynamics ◽  
Surface Roughness ◽  
Surface Morphology ◽  
Md Simulation ◽  
Dynamics Simulation ◽  
Embedded Atom Method ◽  
Homoepitaxial Growth ◽  
Embedded Atom ◽  
Rough Surface Morphology

In this paper, molecular dynamics (MD) simulation of surface morphology during homoepitaxial growth of Copper was investigated. For this purpose, simulations of Cu deposition on the Cu(111) substrate with an incidence energy of 0.06 eV at 300K were performed using the embedded-atom method (EAM). The grown thin film on Cu(111) reveled a rough surface morphology. During deposition, the important fraction of atoms intended for the upper layers undergone a rising rate of about 40% starting from the 2nd period and continued to increase until 65%, while the lower level reached a permanent rate of only 25% by the 4th period. Otherwise, except at the first layer level, the lower layers are incomplete. This void in the lower layers has favored the growth of the upper layers until a rate of 143% and has accelerated their time appearance. Th incidence energy has favored the filling of lower layers by reducing this surface roughness. However, the temperature effect needs more relaxation time to fill the lower layers.

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.

Molecular-Dynamics Study of the Structural Dependence of the Young Modulus of Au Nanowires

2004 ◽  
Vol 818 ◽  
Author(s):  
S. Kameoka ◽  
K. Shintani
Keyword(s):  
Molecular Dynamics ◽  
External Force ◽  
Young Modulus ◽  
Axial Direction ◽  
Dynamics Simulation ◽  
Embedded Atom Method ◽  
Embedded Atom ◽  
Au Nanowire ◽  
Au Nanowires ◽  
Fcc Structure

AbstractThe deformation of Au nanowires of helical multi-shell (HMS) structures and the fcc structure under a tensile external force is addressed by molecular-dynamics simulation. The modified embedded-atom method (MEAM) potential is employed for calculating the interaction between Au atoms. At first, a model nanowire is equilibrated at a specified temperature. Next, the external force in the axial direction is imposed on the Au atoms at the ends of the nanowire. We conclude that the Young modulus of a Au nanowire depends on its atomic structure.

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