Atomistic Modeling of Ultrathin Fe Films on Cu (111)

2000 ◽  
Vol 616 ◽  
Author(s):  
A. Rakotomahevitra ◽  
L. T. Wille ◽  
M. S. Rakotomalala
Keyword(s):  
Md Simulations ◽  
Layer Growth ◽  
Iron Film ◽  
Embedded Atom Method ◽  
Layer By Layer ◽  
Atomistic Modeling ◽  
Iron Films ◽  
Embedded Atom ◽  
Force Range ◽  
Atom Energy

AbstractWe have used the embedded-atom method (EAM) to perform molecular-dynamics (MD) simulations of iron films grown on Cu (111). The iron atoms were randomly deposited, one at a time, above the surface just within the force range of the nearest surface atom. The growth mode is discussed by following the iron film coverage for an incident-atom energy ranged from 0.5eV to 15eV. A transition from island to layer by layer growth is observed as a function of incident energy. The effect of deposition rate is also studied.

Pb Induced Layer-by-Layer Growth and the Dependence on an Amount of Surfactant in the Growth of Ni on Ni(100) Surface

1996 ◽  
Vol 441 ◽  
Author(s):  
M. Iwanami ◽  
M. Kamiko ◽  
T. Matsumoto ◽  
R. Yamamoto
Keyword(s):  
Film Growth ◽  
Three Dimensional ◽  
High Energy ◽  
Layer Growth ◽  
Embedded Atom Method ◽  
Layer By Layer ◽  
Homoepitaxial Growth ◽  
Embedded Atom ◽  
Series Of Experiments ◽  
Modified Embedded Atom Method

AbstractSurfactant epitaxy has been expected to be a powerful method to improve thin film growth from three dimensional island mode to layer-by-layer growth one. Supposing that Pb is the surfactant and Ni is the substrate and deposition metal, we have investigated how the surfactant atoms segregate on surface by computer simulations using the modified embedded atom method. To verify the effect of Pb on the homoepitaxial growth of Ni, we have performed a series of experiments on the growth of Ni on Ni(100) surface with and without Pb using reflection high energy electron diffraction (RHEED). It was clearly found that Pb induced layer-by-layer growth of Ni metal film. The result of the dependence of the growth behavior on the thickness of Pb layer suggests that there is the most suitable thickness of a surfactant layer which is not always the monolayer.

Strengthening Behavior and Tension–Compression Strength–Asymmetry in Nanocrystalline Metal–Ceramic Composites

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
A. M. Dongare ◽  
B. LaMattina ◽  
A. M. Rajendran
Keyword(s):  
Molecular Dynamics ◽  
Volume Fraction ◽  
Md Simulations ◽  
Ceramic Composites ◽  
Embedded Atom Method ◽  
Nanocrystalline Metal ◽  
Rich Region ◽  
Embedded Atom ◽  
Metal Ceramic ◽  
Strength Asymmetry

Metal–ceramic composites are an emerging class of materials for use in the next-generation high technology applications due to their ability to sustain plastic deformation and resist failure in extreme mechanical environments. Large scale molecular dynamics simulations are used to investigate the performance of nanocrystalline metal–matrix composites (MMCs) formed by the reinforcement of the nanocrystalline Al matrix with a random distribution of nanoscale ceramic particles. The interatomic interactions are defined by the newly developed angular-dependent embedded atom method (A-EAM) by combining the embedded atom method (EAM) potential for Al with the Stillinger–Weber (SW) potential for Si in one functional form. The molecular dynamics (MD) simulations are aimed to investigate the strengthening behavior and the tension–compression strength asymmetry of these composites as a function of volume fraction of the reinforcing Si phase. MD simulations suggest that the strength of the nanocomposite increases linearly with an increase in the volume fraction of Si in the Al-rich region, whereas the increase is very sharp in the Si-rich region. The higher strength of the nanocomposite is attributed to the reduced sliding/rotation between the Al/Si and the Si/Si grains as compared to the pure nanocrystalline metal.

A SURFACE X-RAY DIFFRACTION STUDY OF THE GROWTH OF ULTRATHIN LAYERS OF Fe ON Cu(001)

1994 ◽  
Vol 01 (04) ◽  
pp. 631-634 ◽  
Author(s):  
M.A. JAMES ◽  
C. NORRIS ◽  
C.L. NICKLIN ◽  
R.G. VAN SILFHOUT ◽  
P.B. HOWES ◽  
...  
Keyword(s):  
Layer Growth ◽  
Detailed Knowledge ◽  
Exact Nature ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Iron Films ◽  
X Ray ◽  
Diffusion Limited ◽  
Ultrathin Layers ◽  
Fcc Phase

Although it is well known that the γ (fcc) phase of Fe can be stabilised on Cu(001) single crystal substrates, there is still considerable disagreement about the exact nature of the growth mode and the structures that evolve with increasing film thickness. A detailed knowledge of the structure and morphology is essential for a complete understanding of the magnetic properties of ultrathin iron films. Surface X-ray diffraction measurements, recorded in real time during deposition of Fe deposition on Cu(001), are presented. At room temperature, well-defined layer-by-layer growth, with no significant agglomeration of iron, was observed. The specular intensity of the X-ray beam varied parabolically with coverage, as predicted by kinematical theory. Intensity oscillations were observed up to 15 Fe monolayers, at which coverage relaxation to the α (bcc) phase was confirmed. At 85 K the growth is diffusion limited.

A Multi-Scale Modeling Approach to Simulate Intergranular Crack Propagation in Textured Polycrystalline Materials

2011 ◽  
Vol 702-703 ◽  
pp. 932-938
Author(s):  
Muhammad A. Arafin ◽  
Jian Lu ◽  
Jerzy Szpunar
Keyword(s):  
Crack Propagation ◽  
Intergranular Crack ◽  
Md Simulations ◽  
Polycrystalline Materials ◽  
Embedded Atom Method ◽  
Multi Scale ◽  
Modeling Approach ◽  
Embedded Atom ◽  
Scale Modeling ◽  
Different Types

In this paper, a multiscale modeling approach has been developed to simulate the intergranular crack propagation in textured polycrystalline materials. Embedded Atom Method (EAM) and Molecular Dynamics (MD) simulations were carried out to determine the energy and fracture strength of different types of grain boundaries in Ni3Al. Subsequently, the atomistic model has been integrated with the microstructure based model of crack propagation using the Voronoi-Markov Chain-Monte Carlo approach. The model has been utilized to evaluate the crack length for various scenarios and reasonable results are obtained.

Molecular dynamics simulations of grain boundary diffusion in Al using embedded atom method potentials

1995 ◽  
Vol 10 (7) ◽  
pp. 1589-1592 ◽  
Author(s):  
Chun-Li Liu ◽  
S.J. Plimpton
Keyword(s):  
Molecular Dynamics ◽  
Grain Boundary ◽  
Boundary Diffusion ◽  
Md Simulations ◽  
Embedded Atom Method ◽  
Melting Temperatures ◽  
Embedded Atom ◽  
Pair Potentials ◽  
Dynamics Simulations ◽  
First Time

Molecular dynamics (MD) simulations of diffusion in a Σ5(310) [001] Al tilt grain boundary were performed using for the first time three different potentials based on the embedded atom method (EAM). The EAM potentials that produce more accurate melting temperatures also yield activation energies in better agreement with experimental data. Compared to pair potentials, the EAM potentials also give more accurate results.

A Simple Palladium Hydride Embedded Atom Method Potential for Hydrogen Energy Applications

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Iyad Hijazi ◽  
Yang Zhang ◽  
Robert Fuller
Keyword(s):  
Elevated Temperatures ◽  
Clean Energy ◽  
Md Simulations ◽  
Miscibility Gap ◽  
Embedded Atom Method ◽  
Hydrogen Energy ◽  
Hydrogen Purification ◽  
Palladium Hydride ◽  
Embedded Atom ◽  
Eam Potential

When hydrogen is produced from a biomass or coal gasifier, it is necessary to purify it from syngas streams containing components such as CO, CO2, N2, CH4, and other products. Therefore, a challenge related to hydrogen purification is the development of hydrogen-selective membranes that can operate at elevated temperatures and pressures, provide high fluxes, long operational lifetime, and resistance to poisoning while still maintaining reasonable cost. Palladium-based membranes have been shown to be well suited for these types of high-temperature applications and have been widely utilized for hydrogen separation. Palladium's unique ability to absorb a large quantity of hydrogen can also be applied in various clean energy technologies, like hydrogen fuel cells. In this paper, a fully analytical interatomic embedded atom method (EAM) potential for the Pd-H system has been developed, that is easily extendable to ternary Palladium-based hydride systems, such as Pd-Cu-H and Pd-Ag-H. The new potential has fewer fitting parameters than previously developed EAM Pd-H potentials and is able to accurately predict the cohesive energy, lattice constant, bulk modulus, elastic constants, melting temperature, and the stable Pd-H structures in molecular dynamics (MD) simulations with various hydrogen concentrations. The EAM potential also well predicts the miscibility gap, the segregation of the palladium hydride system into dilute (α), and concentrated (β) phases.

Molecular Dynamics Study of Mass Transport Properties of Liquid Cu-Ag Alloys

2016 ◽  
Vol 9 ◽  
pp. 58-72 ◽  
Author(s):  
U. Sarder ◽  
Alexander V. Evteev ◽  
Elena V. Levchenko ◽  
A. Kromik ◽  
I.V. Belova ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Mass Transport ◽  
Transport Properties ◽  
Diffusion Coefficients ◽  
Md Simulations ◽  
Embedded Atom Method ◽  
Self Diffusion ◽  
Phenomenological Coefficient ◽  
Embedded Atom ◽  
Kinetics Of

In this study, mass transport properties of liquid Cu-Ag alloys are investigated over wide temperature and composition ranges. The calculations are performed within the framework of the Green-Kubo (GK) formalism by using equilibrium molecular dynamics (MD) simulations along with one of the most reliable embedded-atom method potentials for this system developed by [P. Williams et al.: Modell. Simul. Mater. Sci. Eng. vol. 14 (2006), p. 817]. The approach employed allows for evaluation of the components’ self-diffusion coefficients as well as the phenomenological coefficient for mass transport Lcc. The results obtained in this study can be used to predict the kinetics of solidification of real liquid Cu-Ag alloys.

Parallel Molecular Dynamics With the Embedded Atom Method

1992 ◽  
Vol 291 ◽  
Author(s):  
Steven J. Plimpton ◽  
Bruce A. Hendrickson
Keyword(s):  
Molecular Dynamics ◽  
Md Simulations ◽  
Parallel Computers ◽  
Embedded Atom Method ◽  
Geometric Information ◽  
Parallel Methods ◽  
Embedded Atom ◽  
Multiple Data ◽  
Parallel Molecular Dynamics ◽  
Force Decomposition

ABSTRACTParallel computing offers new capabilities for using molecular dynamics (MD) to simulate larger numbers of atoms and longer time scales. In this paper we discuss two methods we have used to implement the embedded atom method (EAM) formalism for molecular dynamics on multiple-instruction/multiple-data (MIMD) parallel computers. The first method (atom-decomposition) is simple and suitable for small numbers of atoms. The second method (force-decomposition) is new and is particularly appropriate for the EAM because all the computations are between pairs of atoms. Both methods have the advantage of not requiring any geometric information about the physical domain being simulated. We present timing results for the two parallel methods on a benchmark EAM problem and briefly indicate how the methods can be used in other kinds of materials MD simulations.

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