scholarly journals Free Energy Calculations of Cu-Sn Interfaces

1995 ◽  
Vol 398 ◽  
Author(s):  
R. Ravelo ◽  
M. Baskes
Keyword(s):  
Molecular Dynamics ◽  
Free Energy ◽  
Free Energy Calculations ◽  
Embedded Atom Method ◽  
Free Energies ◽  
Embedded Atom ◽  
Adiabatic Switching ◽  
Atomic Interactions ◽  
Bond Bending ◽  
Modified Embedded Atom Method

ABSTRACTExcess free energies of solid Cu - Solid Sn and Solid Cu - liquid Sn have been calculated employing an adiabatic switching formalism in a Molecular Dynamics (MD) framework. The atomic interactions are described by modified embedded atom method (MEAM) potentials which includes the angular dependence of the electron density to describe bond bending forces necessary to model covalent materials.

Some Thermodynamic Properties of NiAl Calculated by Molecular Dynamics Simulations

1988 ◽  
Vol 133 ◽  
Author(s):  
P. C. Clapp ◽  
M. J. Rubins ◽  
S. Charpenay ◽  
J. A. Rifkin ◽  
Z. Z. Yu ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Free Energy ◽  
Boundary Energy ◽  
Alloy System ◽  
Embedded Atom Method ◽  
Interatomic Potentials ◽  
Surface Energies ◽  
Embedded Atom ◽  
Dynamics Simulations ◽  
Anti Phase Boundary

ABSTRACTCalculations of the surface free energy and anti-phase boundary energy as a function of low index orientations and temperature have been determined for equiatomic perfectly ordered bcc NiAl via molecular dynamics computer simulations. The simulations utilized an Embedded Atom Method calculation of the interatomic potentials and volume forces in the Ni-As alloy system. Values of about 0.95, 1.6, 1.9 and 2.0 J/m2 were found for surface energies of the {100}, {110}, {112} and {111} orientations:, respectively. APB energies of about 0.24 and 0.38 J/m2 were determined for {110} and {112} boundaries, respectively. In addition, we have examined the phase stability and relative energies of the ordered bcc, fcc and bct phases at low temperature, and find a bct phase with c/a = 1.32 slightly lower in energy than the bcc, presaging the martensitic transformation that occurs at finite temperatures in more nickel rich alloys.

scholarly journals Molecular Dynamics Studies of Thin-Films of Sn On Cu

1997 ◽  
Vol 492 ◽  
Author(s):  
R. Ravelo ◽  
J. Aguilar ◽  
M. I. Baskes
Keyword(s):  
Thin Films ◽  
Molecular Dynamics ◽  
Melting Temperature ◽  
Embedded Atom Method ◽  
Interaction Potentials ◽  
Embedded Atom ◽  
Evolution Dynamics ◽  
Modified Embedded Atom Method ◽  
Experimental Values ◽  
Diffusion Activation

ABSTRACTUsing Molecular Dynamics, the evolution dynamics of Sn on the (111) and (100) surfaces of Cu have been investigated as a function of coverage and temperature. The interaction potentials are described by modified embedded atom method (MEAM) potentials. The calculated diffusion activation energies of Cu in Sn and Sn in Cu agree reasonably well with experimental values. We find that the structure of the overlayer depends on the morphology of the substrate and remains stable up to temperatures of the order of 70% of the melting temperature of the substrate at which diffusion of Sn into the substrate and Cu atoms onto the overlayer is observed.

scholarly journals Atomistic Simulations of Pure Tin Based on a New Modified Embedded-Atom Method Interatomic Potential

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 900 ◽  
Author(s):  
Won-Seok Ko ◽  
Dong-Hyun Kim ◽  
Yong-Jai Kwon ◽  
Min Lee
Keyword(s):  
Density Functional ◽  
Nearest Neighbor ◽  
Interatomic Potential ◽  
Free Energy Calculations ◽  
Embedded Atom Method ◽  
Force Matching ◽  
Embedded Atom ◽  
Β Phase ◽  
Diffusion Phenomena ◽  
Modified Embedded Atom Method

A new interatomic potential for the pure tin (Sn) system is developed on the basis of the second-nearest-neighbor modified embedded-atom-method formalism. The potential parameters were optimized based on the force-matching method utilizing the density functional theory (DFT) database of energies and forces of atomic configurations under various conditions. The developed potential significantly improves the reproducibility of many fundamental physical properties compared to previously reported modified embedded-atom method (MEAM) potentials, especially properties of the β phase that is stable at the ambient condition. Subsequent free energy calculations based on the quasiharmonic approximation and molecular-dynamics simulations verify that the developed potential can be successfully applied to study the allotropic phase transformation between α and β phases and diffusion phenomena of pure tin.

Computer Simulations of Two-Dimensional Sn-Cu Alloys on (100) and (111) Cu Surfaces

1999 ◽  
Vol 570 ◽  
Author(s):  
Jose F. Aguilar ◽  
R. Ravelo ◽  
M. Baskes
Keyword(s):  
Thin Films ◽  
Computer Simulations ◽  
Embedded Atom Method ◽  
Higher Moments ◽  
Two Dimensional ◽  
Ion Scattering ◽  
Embedded Atom ◽  
Cu Alloys ◽  
Atomic Interactions ◽  
Modified Embedded Atom Method

ABSTRACTWe have performed calculations of Sn deposition on Cu(111) and Cu(100) surfaces. The atomic interactions are described by modified embedded atom method (MEAM) potentials. This is a modification of the embedded atom method (EAM) to include higher moments in the electron density. We find the at low coverages Sn deposited on Cu(111) leads to the formation of a two-dimensional (2D) alloy phase with a p (√3 × √3)-R 30° structure which is stable up to temperatures of 900K. These results are in agreement with ion-scattering experiments of thin films of Sn on Cu(111). For deposition of Sn on Cu(100), a 0.25 monolayer (ML) coverage results in the formation of a stable 2D alloy phase with a p(2 × 2) structure. This result is also in agreement with LEED measurements.

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