scholarly journals A numerical fitting procedure for the embedded atom method interatomic potential and a bridged finite element-molecular dynamics method for large atomic systems

2021 ◽  
Author(s):  
Karthik Narayan
Keyword(s):  
Molecular Dynamics ◽  
Md Simulation ◽  
Embedded Atom Method ◽  
Discretization Scheme ◽  
Element Discretization ◽  
Atomic Systems ◽  
Embedded Atom ◽  
Fitting Procedure ◽  
Numerical Fitting ◽  
Eam Potential

This thesis presents a powerful numerical fitting procedure for generating Embedded Atom Method (EAM) inter-atomic potentials for pure Face Centred Cubic (FCC) and Body Centred Cubic (BCC) metals. The numerical fitting procedure involves assuming a reasonable parameterized form for a portion of the EAM potential, and then fitting the remaining portion to select thermal and elastic properties of the metal. Molecular Dynamics (MD) simulation is used to effect the fitting procedure. The procedure is used to generate an EAM potential for copper, an FCC metal. This resulting EAM potential is used to conduct MD simulations of perfect copper crystals containing voids of different geometries. Following this, a bridged Finite Element-Molecular Dynamics (FE-MD) method is presented, which can be used to simulate large atomic systems much more efficiently than MD simulation alone. The method implements a novel element discretization scheme proposed by the author that is so general that it can be applied to any system of objects interacting with each other via any potential (simple or complex, EAM or otherwise). This bridged FE-MD method is used to reanalyze the voids in the copper crystal lattice. The resulting virial stress increment patterns are found to agree remarkably with the earlier MD simulation results. Furthermore, the bridged FE-MD method is much quicker than the pure MD simulation. These two facts prove the power and usefulness of the bridged FE-MD method, and validate the proposed element discretization scheme

scholarly journals A numerical fitting procedure for the embedded atom method interatomic potential and a bridged finite element-molecular dynamics method for large atomic systems

2021 ◽  
Author(s):  
Karthik Narayan
Keyword(s):  
Molecular Dynamics ◽  
Md Simulation ◽  
Embedded Atom Method ◽  
Discretization Scheme ◽  
Element Discretization ◽  
Atomic Systems ◽  
Embedded Atom ◽  
Fitting Procedure ◽  
Numerical Fitting ◽  
Eam Potential

This thesis presents a powerful numerical fitting procedure for generating Embedded Atom Method (EAM) inter-atomic potentials for pure Face Centred Cubic (FCC) and Body Centred Cubic (BCC) metals. The numerical fitting procedure involves assuming a reasonable parameterized form for a portion of the EAM potential, and then fitting the remaining portion to select thermal and elastic properties of the metal. Molecular Dynamics (MD) simulation is used to effect the fitting procedure. The procedure is used to generate an EAM potential for copper, an FCC metal. This resulting EAM potential is used to conduct MD simulations of perfect copper crystals containing voids of different geometries. Following this, a bridged Finite Element-Molecular Dynamics (FE-MD) method is presented, which can be used to simulate large atomic systems much more efficiently than MD simulation alone. The method implements a novel element discretization scheme proposed by the author that is so general that it can be applied to any system of objects interacting with each other via any potential (simple or complex, EAM or otherwise). This bridged FE-MD method is used to reanalyze the voids in the copper crystal lattice. The resulting virial stress increment patterns are found to agree remarkably with the earlier MD simulation results. Furthermore, the bridged FE-MD method is much quicker than the pure MD simulation. These two facts prove the power and usefulness of the bridged FE-MD method, and validate the proposed element discretization scheme

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.

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.

Molecular Dynamics Study of Pb Overlayer on Cu(100)

1990 ◽  
Vol 202 ◽  
Author(s):  
M. Karimi ◽  
P. Tibbits ◽  
D. Ila ◽  
I. Dalins ◽  
G. Vidali
Keyword(s):  
Molecular Dynamics ◽  
Structure Factor ◽  
Md Simulation ◽  
Dimensional Structure ◽  
Embedded Atom Method ◽  
Two Dimensional ◽  
Ordered Structure ◽  
Embedded Atom

ABSTRACTIsothermal-isobaric Molecular Dynamics (MD) simulation of a submonolayer Pb film in c(2×2) ordered structure adsorbed on a Cu(100) substrate showed retention of order to high T. The Embedded Atom Method (EAM) calculated the energy of atoms of overlayer and substrate. The time-averaged squared modulus of the two dimensional structure factor for the Pb overlayer measured the order of the overlayer. The results are for increasing T only, and require verification by simulated cooling.

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.

Cascade Overlap in hcp Zirconium: Defect Accumulation and Microstructure Evolution with Radiation using Molecular Dynamics Simulations

2013 ◽  
Vol 1514 ◽  
pp. 37-42 ◽  
Author(s):  
Prithwish K. Nandi ◽  
Jacob Eapen
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Microstructure Evolution ◽  
Stacking Faults ◽  
Embedded Atom Method ◽  
Shockley Partial Dislocation ◽  
Embedded Atom ◽  
Defect Accumulation ◽  
Dynamics Simulations ◽  
Eam Potential

ABSTRACTMolecular dynamics simulations are performed to investigate the defect accumulation and microstructure evolution in hcp zirconium (Zr) – a material which is widely used as clad for nuclear fuel. Cascades are generated with a 3 keV primary knock-on atom (PKA) using an embedded atom method (EAM) potential with interactions modified for distances shorter than 0.1 Å. With sequential cascade simulations we show the emergence of stacking faults both in the basal and prism planes, and a Shockley partial dislocation on the basal plane.

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.

A Molecular Dynamics Study of Cu Segregation to the Σ11 Grain Boundary In Al

1996 ◽  
Vol 428 ◽  
Author(s):  
Hanchen Huang ◽  
T. Diaz de la Rubia ◽  
M. J. Fluss
Keyword(s):  
Molecular Dynamics ◽  
Grain Boundary ◽  
Md Simulation ◽  
Atomic Level ◽  
Embedded Atom Method ◽  
Simulation Studies ◽  
Embedded Atom

AbstractWe present results of molecular dynamics (MD) simulation studies of Cu segregation to the Σ11 grain boundary (GB) in Al. The simulations were performed with Embedded Atom Method (EAM) potentials for Al and Al-Cu. The results predict that copper atoms tend to order along either side of the interface even at the pure symmetrical GB, forming alternating chains along the direction. The nucleation of the chains is driven by a change in the local atomic level stress induced by the pre-existing Cu atoms at the GB.

Molecular Dynamics Simulation on Formation of Icosahedron and Coalescence of Pt Nanoclusters

2007 ◽  
Vol 539-543 ◽  
pp. 3546-3550 ◽  
Author(s):  
Sung Hoon Lee ◽  
Sang Soo Han ◽  
Jeung Ku Kang ◽  
Hyuck Mo Lee
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Formation Energy ◽  
Md Simulation ◽  
Icosahedral Phase ◽  
Dynamics Simulation ◽  
Minimum Size ◽  
Embedded Atom Method ◽  
Pt Nanoclusters ◽  
Embedded Atom

The molecular dynamics (MD) simulation employing the embedded atom method (EAM) has been performed to examine the phase stability of Pt nanoclusters, Ptn (n=38, 147, 309 and 561 atoms) with size and temperature. From heating and freezing curves of the nanoclusters, the clusters (Pt147, Pt309 and Pt561) larger than 1 nm in size showed an icosahedral morphology near 460 ~ 660 K during freezing, where the formation energy of the icosahedral phase is 0.051 eV/atom for Pt147, 0.056eV/atom for Pt309 and 0.067 eV/atom for Pt561. We also investigated coalescence between two Pt nanoclusters and observed that the minimum size of the coalescent one is around 1 nm at 673 K.

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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