The Structure and Composition of Interphase Boundaries in Ni/Ag-(001) Thin Films Doped with Au

1985 ◽  
Vol 56 ◽  
Author(s):  
S.A. Dregia ◽  
C.L. Bauer ◽  
P. Wynblatt
Keyword(s):  
Thin Films ◽  
Shear Modulus ◽  
Computer Simulations ◽  
Interphase Boundary ◽  
Interaction Potential ◽  
Experimental Studies ◽  
Embedded Atom Method ◽  
Embedded Atom ◽  
Interphase Boundaries

AbstractComputer simulations of the Ni/Ag-(001) interphase boundary have been performed with the Embedded Atom Method. The relaxed atomic configurations, the periodic interaction potential, the shear modulus of the interface, and the interaction of an Au impurity with the interface have been evaluated. In addition, experimental studies have been conducted on the same system; and the structure and composition of the interface have been simultaneously examined.

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.

Monte Carlo Modeling of Interphase Boundaries in Cu-Ag and Cu-Ag-Au Alloys

1990 ◽  
Vol 205 ◽  
Author(s):  
P. Bacher ◽  
P. Wynblatt
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Binary System ◽  
Ternary Alloy ◽  
Embedded Atom Method ◽  
Misfit Dislocations ◽  
Monte Carlo Modeling ◽  
Embedded Atom ◽  
Composition And Structure ◽  
Interphase Boundaries

AbstractMonte Carlo simulation, in conjunction with the embedded atom method, has been used to model the composition and structure of a semicoherent (001) interphase boundary separating coexisting Cu-rich and Ag-rich phases in a binary Cu-Ag alloy. The results are compared with earlier simulations of the same boundary in a Cu-Ag-Au alloy, in which Au was found to segregate to the interface, and the boundary was found to be unstable with respect to break-up into {111} facets. The boundary in the binary system is also unstable to faceting, but displays both {100} as well as {111} facets. It is concluded that Au segregation in the ternary alloy plays an important role in stabilizing the {111} facets. The interplay between the misfit dislocations present at the interface, and the compositional features of the boundary are also discussed.

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.

Stability of tight-packed metals with the embedded-atom method

1992 ◽  
Vol 7 (4) ◽  
pp. 883-887 ◽  
Author(s):  
R.A. Johnson
Keyword(s):  
Shear Modulus ◽  
Bulk Modulus ◽  
Cohesive Energy ◽  
Input Data ◽  
Formation Energy ◽  
Stacking Faults ◽  
Embedded Atom Method ◽  
Distance Curve ◽  
Embedded Atom ◽  
Cutoff Distance

Relationships between embedded-atom method parameters and the energies of fcc-hcp stability and intrinsic and extrinsic fcc stacking-faults were studied for Cu, Ag, Au, Ni, Pd, and Pt. It was found that the relative magnitudes of these energies for different metals are determined primarily by the physical input data and are almost independent of the cutoff distance and the functions used in the model. These energies increase with increasing vacancy formation energy, decrease with increasing atomic volume and shear modulus, and are almost independent of variations in the cohesive energy and the bulk modulus. However, the shape of the energy versus cutoff distance curve is almost the same for all six metals and is determined primarily by the cutoff distance and the functions used in the model. The shape for a given model is almost independent of the physical input parameters used for fitting to specific metals, can yield either positive or negative values (determined primarily by the cutoff distance), and is similar for all three energies.

Computer Simulations of Epitaxial Interfaces

1988 ◽  
Vol 141 ◽  
Author(s):  
S. A. Dregia ◽  
P. Wynblatt ◽  
C. L. Bauer
Keyword(s):  
Orientation Relationship ◽  
Computer Simulations ◽  
Interfacial Energy ◽  
Boundary Energy ◽  
Enthalpy Of Mixing ◽  
Embedded Atom Method ◽  
Misfit Dislocations ◽  
Maximum Displacement ◽  
Embedded Atom ◽  
Atomic Diameter

AbstractThe embedded-atom method was applied in computer simulations to study epitaxial Cu/Ag interfaces in cube-on-cube orientation relationship. Coherent and semicoherent interfaces were studied with inclinations parallel to (001), (011) and (111). The coherent boundary energy depends strongly on the predicted enthalpy of mixing. The interfacial energy for semicoherent boundaries was highly anisotropic, having its largest value (549 mJ/m2) for the (011) interface and its smallest value (231 mJ/m2) for the (111) interface. The periodic elastic relaxations correspond to networks of misfit dislocations lying in the plane of the interface; the maximum displacement in the (011) interface is about one-third the atomic diameter, but only one-eighth the atomic diameter in the (111) interface.

Atomistic Structure and Composition of a Ag/Ni Interphase Boundary

1990 ◽  
Vol 187 ◽  
Author(s):  
P. Gumbsch ◽  
M. S. Daw ◽  
S. M. Foiles ◽  
H. F. Fischmeister
Keyword(s):  
Interphase Boundary ◽  
Minimum Energy ◽  
Embedded Atom Method ◽  
Interface Plane ◽  
Misfit Dislocations ◽  
Abrupt Transition ◽  
Embedded Atom ◽  
Induced Stresses ◽  
Atomistic Structure ◽  
The Ideal

AbstractUsing the embedded atom method we atomistically model the compensation of the misfit induced stresses in a “cube on cube” oriented Ag/Ni bicrystal with (011) interface plane, in which zones of maximum misfit (misfit dislocations) run along the [100] and the [011] directions.The ideal interface corresponds to an abrupt transition between Ag and Ni. The interfacial enthalpy is found to be lowered by the introduction of vacancies on the Ni side (equivalently, vacancies are trapped on the Ni side of the boundary). Pursuing this perspective, we find that the interfacial enthalpy is lowered considerably by the removal of a complete line of Ni atoms along the [011] direction from the Ni side of the boundary. The minimum energy configuration consists of a Ni layer whose atomic density is reduced by 16% sandwiched between the ordinary Ni and Ag lattices.

Embedded Atom Method Study of Pd Thin Films on Cu(001)

1998 ◽  
Vol 05 (05) ◽  
pp. 959-963 ◽  
Author(s):  
A. Bilić ◽  
Y. G. Shen ◽  
B. V. King ◽  
D. J. O'Connor
Keyword(s):  
Thin Films ◽  
Monte Carlo ◽  
Double Layer ◽  
Single Layer ◽  
Surface Alloy ◽  
Experimental Results ◽  
Embedded Atom Method ◽  
Layer Surface ◽  
Embedded Atom ◽  
Topmost Layer

We have studied the structures formed by the deposition of 0.5 and 1 monolayer (ML) of Pd on a Cu(001) surface using Monte Carlo (MC) simulations and static optimizations. The energetics are given by the semiempirical embedded atom method (EAM). At 0.5 ML Pd coverage we find that a Pd–Cu c (2×2) single layer surface alloy is created, consistent with experimental observations. At 1 ML Pd coverage a double layer c (2×2) Cu–Pd surface alloy is found to be energetically favored over structures with a clock-reconstructed topmost layer. However, metastable configurations of the top layer consisting of a clock-rotated phase with the (2×2) p4g symmetry coexisting with phases with c (2×2) and p (2×2) symmetries can also be obtained, in agreement with the experimental results.

Stress Induced Martensitic(SIM) Transformations In B2 NiAl Observed in Crack Propagation Computer Simulations

1990 ◽  
Vol 213 ◽  
Author(s):  
Donghyun Kim ◽  
P. C. Clapp ◽  
J. A. Rifkin
Keyword(s):  
Molecular Dynamics ◽  
Martensitic Transformation ◽  
Crack Propagation ◽  
Computer Simulations ◽  
Alloy System ◽  
External Stress ◽  
Embedded Atom Method ◽  
Mode I ◽  
Al Alloy ◽  
Embedded Atom

ABSTRACTIn molecular dynamics studies of 10,000 atom arrays of stoichiometric B2 NiAl containing a crack under external stress in Mode I loading, it has been observed that a martensitic transformation generally occurs (starting in the vicinity of the crack tip) prior to the generation of dislocations and/or the propagation of the crack. The martensitic phase appears to be 2H, in agreement with experimental observations of SIM at higher Ni compositions (62 at % Ni). The interatomic interactions used in the simulations were the Embedded Atom Method (EAM) potentials developed by Voter and Chen [1] for the Ni-Al alloy system.

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