× Updated! Potentials that share interactions are now listed as related models.
 
Citation: S.M.A.A. Alvi, A. Faiyad, M.A.M. Munshi, M. Motalab, M.M. Islam, and S. Saha (2022), "Cyclic and tensile deformations of Gold–Silver core shell systems using newly parameterized MEAM potential", Mechanics of Materials, 169, 104304. DOI: 10.1016/j.mechmat.2022.104304.
Abstract: Gold–Silver (Au-Ag) core-shell nanostructures have significant applicability in stretchable and biocompatible electronics where endurance under high tensile and cyclic loading is a requirement. This work, for the first time, quantitatively investigates the role of dislocations and defect interaction governing the mechanical behavior of Au-Ag and Ag-Au Core-shell nanostructures under tensile and cyclic loading using molecular dynamics (MD) simulation. For accurate representation of the underlying physics, a novel modified embedded atomic model (MEAM) interatomic potential for pristine Au, Ag and their alloys is parameterized through two different density functional theory (DFT) schemes. Using the new potential for MD simulations, the cyclic loading properties of pristine and core-shell nanowires (NWs) in a strain range of -15%-15% for 10 cycles are conducted. The tensile behavior of pristine and core-shell NWs is also explored for temperatures between 300 K and 600 K. A comparative analysis between Core-shell structures and their pristine counterparts are carried out. Our results suggest that Ag-Au Core-shell NW exhibit superior stress-strain reversibility under cyclic loading among the structures examined. Ag-Au exhibit the highest dislocation formation and near-complete annihilation of defects consistently. Au-Ag also present improved cyclic loading properties than its pristine counterparts. For tensile loading, all four structures exhibited deterioration in strength with increasing temperature. Thermal softening is observed to be more prominent in Au-Ag core-shell NWs compared to Ag-Au. Our work lays out a foundation for exploration of mechanical properties of Au-Ag systems using the MEAM potential which will help design components for stretchable electronics and creates a pathway for further exploration of similar binary alloy systems.

See Computed Properties
Notes: These files were provided by Sourav Saha on May 6, 2022 and posted with his permission.
File(s):
Citation: G.P. Purja Pun (2017), "to be published".

LAMMPS pair_style eam/alloy (2017--Purja-Pun-G-P--Au--LAMMPS--ipr1)
See Computed Properties
Notes: These files were sent by G.P. Purja Pun (George Mason) on 7 Sept. 2017 and posted with his permission.
File(s):
See Computed Properties
Notes: Listing found at https://openkim.org. This KIM potential is based on the files from 2017--Purja-Pun-G-P--Au--LAMMPS--ipr1.
Link(s):
Citation: R.S. Elliott, and A. Akerson (2015), "Efficient "universal" shifted Lennard-Jones model for all KIM API supported species".

Notes: This is the Au interaction from the "Universal" parameterization for the openKIM LennardJones612 model driver.The parameterization uses a shifted cutoff so that all interactions have a continuous energy function at the cutoff radius. This model was automatically fit using Lorentz-Berthelotmixing rules. It reproduces the dimer equilibrium separation (covalent radii) and the bond dissociation energies. It has not been fitted to other physical properties and its ability to model structures other than dimers is unknown. See the README and params files on the KIM model page for more details.

See Computed Properties
Notes: Listing found at https://openkim.org.
Link(s):
Citation: G.E. Norman, S.V. Starikov, and V.V. Stegailov (2012), "Atomistic simulation of laser ablation of gold: Effect of pressure relaxation", Journal of Experimental and Theoretical Physics, 114(5), 792-800. DOI: 10.1134/s1063776112040115.
Abstract: The process of ablation of a gold target by femto- and picosecond laser radiation pulses has been studied by numerical simulations using an atomistic model with allowance for the electron subsystem and the dependence of the ion-ion interaction potential on the electron temperature. Using this potential, it is possible to take into account the change in the physical properties of the ion subsystem as a result of heating of the electron subsystem. The results of simulations reveal a significant difference between the characteristics of metal ablation by laser pulses of various durations. For ablation with subpicosecond pulses, two mechanisms of metal fracture related to the evolution of electronic pressure in the system are established.
Citation: S.V. Starikov, A.Y. Faenov, T.A. Pikuz, I.Y. Skobelev, V.E. Fortov, S. Tamotsu, M. Ishino, M. Tanaka, N. Hasegawa, M. Nishikino, T. Kaihori, T. Imazono, M. Kando, and T. Kawachi (2014), "Soft picosecond X-ray laser nanomodification of gold and aluminum surfaces", Applied Physics B, 116(4), 1005-1016. DOI: 10.1007/s00340-014-5789-y.
Abstract: Experimental and theoretical investigations of aluminum (Al) and gold (Au) surface modification by soft X-ray laser pulse are presented. Well-polished samples of Al and Au are irradiated by ps-duration pulse with wavelength of 13.9 nm at the energy range of 24-72 nJ. Differences in the melting and the ablation processes for those materials are observed. It is shown that at low laser pulse energy, the nanoscale ripples on the surface may be induced by melting without following ablation. In that case, the nanoscale changes in the surface are caused by splash of molten metal under gradient of fluence. At higher laser pulse energy, the ablation process occurs and craters are formed on the surface. However, the melting determines the size of the modified surface at all ranges of the laser energies. For interpretation of experimental results, the atomistic simulations of melting and ablation processes in Al and Au are provided. The calculated threshold fluencies for melting and ablation are well consistent with measured ones.

LAMMPS pair_style eam/alloy (2012--Norman-G-E--Au--LAMMPS--ipr1)
See Computed Properties
Notes: These files were submitted by Sergey Starikov on July 23, 2018. This EAM-potential describes Au at various electronic temperatures (0.1 eV, 1.5 eV, 3.0 eV, 4.5 eV, 6.0 eV). It is implemented as a set of EAM-potentials for alloy where each component corresponds to some electron temperature. This version is compatible with LAMMPS. Validation and usage information can be found in Verification.pdf. It should be noted that the potential may be used at classical molecular dynamics simulation for study of room-temperature properties. In this case, only "Au" type of alloy is necessary.
File(s):
Citation: P.A.T. Olsson (2010), "Transverse resonant properties of strained gold nanowires", Journal of Applied Physics, 108(3), 034318. DOI: 10.1063/1.3460127.
Abstract: In this work, resonant and elastic properties of single crystal gold nanowires have been studied through classical molecular dynamics simulations. The considered nanowires have perfect square cross sections and are oriented with the [100] direction along the wire axis and with 100 side surfaces. Three different sizes were simulated; 4.08×4.08 nm2, 5.71×5.71 nm2, and 7.34×7.34 nm2 cross sectional dimensions, with the respective unrelaxed lengths 49.0 nm, 68.5 nm, and 88.1 nm and the simulations were performed at two different temperatures, 4.2 K and 300 K. Tensile simulations reveal, that the stiffness decreases with decreasing size, and that the size dependence for nanowires at 4.2 K can be accurately described using the concept of surface energy. Comparing results from the resonant simulations reveals that the fundamental eigenfrequency is in good agreement with predictions from Bernoulli–Euler continuum beam theory when the size dependence of the stiffness is taken into account. The eigenfrequencies of the first and second excited modes turn out to be low in comparison with analytical Bernoulli–Euler continuum calculations.

Notes: This potential has previously been used in a series of nanowire modeling projects by Dr. Olsson. Furthermore, he noted that the potential is not documented in the actual paper, it is rather available in the supplementary data accompanying the paper.

EAM tabulated functions (2010--Olsson-P-A-T--Au--table--ipr1)
Notes: These files were sent by Pär A. T. Olsson (Malmoe University, Sweden) on 5 July 2016 and posted with his permission.
File(s):
F(ρ): F_au.plt
ρ(r): rho_au.plt
φ(r): phi_au.plt

LAMMPS pair_style eam/alloy (2010--Olsson-P-A-T--Au--LAMMPS--ipr1)
See Computed Properties
Notes: These files were sent by Pär A. T. Olsson (Malmoe University, Sweden) on 5 July 2016 and posted with his permission.
File(s):
See Computed Properties
Notes: Listing found at https://openkim.org. This KIM potential is based on the files from 2010--Olsson-P-A-T--Au--LAMMPS--ipr1.
Link(s):
Citation: V.V. Zhakhovskii, N.A. Inogamov, Y.V. Petrov, S.I. Ashitkov, and K. Nishihara (2009), "Molecular dynamics simulation of femtosecond ablation and spallation with different interatomic potentials", Applied Surface Science, 255(24), 9592-9596. DOI: 10.1016/j.apsusc.2009.04.082.
Abstract: Fast heating of target material by femtosecond laser pulse (fsLP) with duration τL~40–100fs results in the formation of thermomechanically stressed state. Its unloading may cause frontal cavitation of subsurface layer at a depth of 50nm for Al and 100nm for Au. The compression wave propagating deep into material hits the rear-side of the target with the formation of rarefaction wave. The last may produce cracks and rear-side spallation. Results of MD simulations of ablation and spallation of Al and Au metals under action fsLP are presented. It is shown that the used EAM potentials (Mishin et al. and our new one) predict the different ablation and spallation thresholds on absorbed fluence in Al: ablation Fa=6065mJ/cm2 and spallation Fs=120190mJ/cm2, where numbers in brackets show the corresponding values for Mishin potential. The strain rate in spallation zone was 4.3×10^9 1/s at spallation threshold. Simulated spall strength of Al is 7.48.7GPa, that is noticeably less than 10.314GPa obtained from acoustic approximation with the use of velocity pullback on velocity profile of free rear surface. The ablation threshold Fa≈120mJ/cm2 and crater depth of 110nm are obtained in MD simulations of gold with the new EAM potential. They agree well with experiment.

Notes: Dr. Zhakhovsky noted that the potential was used in several works related to MD simulations of laser ablation and shock-wave loading, and that the potential was designed to reproduce the cold stress curves, the shock Hugoniot, and the melting point with good accuracy.

LAMMPS pair_style eam/alloy (2009--Zhakhovskii-V-V--Au--LAMMPS--ipr1)
See Computed Properties
Notes: These files were sent by V.V. Zhakhovsky (VNIIA) on 25 Feb. 2017 and posted with his permission. Update March 15, 2020: This version was identified to not be compatible with LAMMPS.
File(s): retracted


LAMMPS pair_style eam/alloy (2009--Zhakhovskii-V-V--Au--LAMMPS--ipr2)
See Computed Properties
Notes: This file was posted on 15 March 2020. It corrects the 4th line to be compatible with LAMMPS by removing the comment "3.81 ! cohesive energy [eV] to check".
File(s):
See Computed Properties
Notes: Listing found at https://openkim.org. This KIM potential is based on the files from 2009--Zhakhovskii-V-V--Au--LAMMPS--ipr1.
Link(s):
Citation: G. Grochola, S.P. Russo, and I.K. Snook (2005), "On fitting a gold embedded atom method potential using the force matching method", The Journal of Chemical Physics, 123(20), 204719. DOI: 10.1063/1.2124667.
Abstract: We fit a new gold embedded atom method (EAM) potential using an improved force matching methodology which included fitting to high-temperature solid lattice constants and liquid densities. The new potential shows a good overall improvement in agreement to the experimental lattice constants, elastic constants, stacking fault energy, radial distribution function, and fcc/hcp/bcc lattice energy differences over previous potentials by Foiles, Baskes, and Daw (FBD) [Phys. Rev. B 33, 7983 (1986)] Johnson [Phys. Rev. B 37, 3924 (1988)], and the glue model potential by Ercolessi et al. [Philos. Mag. A 50, 213 (1988)]. Surface energy was improved slightly as compared to potentials by FBD and Johnson but as a result vacancy formation energy is slightly inferior as compared to the same potentials. The results obtained here for gold suggest for other metal species that further overall improvements in potentials may still be possible within the EAM framework with an improved fitting methodology. On the other hand, we also explore the limitations of the EAM framework by attempting a brute force fit to all properties exactly which was found to be unsuccessful. The main conflict in such a brute force fit was between the surface energy and the liquid lattice constant where both could not be fitted identically. By intentionally using a very large number of spline sections for the pair potential, electron-density function, and embedding energy function, we eliminated a lack of functional freedom as a possible cause of this conflict and hence can conclude that it must result from a fundamental limitation in the EAM framework.

EAM tabulated functions (2005--Grochola-G--Au--table--ipr1)
Notes: These files were approved by G. Grochola.
File(s):
LAMMPS pair_style eam/alloy (2005--Grochola-G--Au--LAMMPS--ipr1)
See Computed Properties
Notes: This file was generated by C.A. Becker from the files above that were approved by G. Grochola (RMIT University) and posted with his permission on 21 Feb. 2011. This version is compatible with LAMMPS. Validation and usage information can be found in Au-Grochola-JCP05-conversion-notes_v2.pdf. If you use this eam.alloy file, please credit the website in addition to the original reference.
File(s):
See Computed Properties
Notes: Listing found at https://openkim.org. This KIM potential is based on the files from 2005--Grochola-G--Au--LAMMPS--ipr1.
Link(s):
Citation: X.W. Zhou, R.A. Johnson, and H.N.G. Wadley (2004), "Misfit-energy-increasing dislocations in vapor-deposited CoFe/NiFe multilayers", Physical Review B, 69(14), 144113. DOI: 10.1103/physrevb.69.144113.
Abstract: Recent molecular dynamics simulations of the growth of [Ni0.8Fe0.2/Au] multilayers have revealed the formation of misfit-strain-reducing dislocation structures very similar to those observed experimentally. Here we report similar simulations showing the formation of edge dislocations near the interfaces of vapor-deposited (111) [NiFe/CoFe/Cu] multilayers. Unlike misfit dislocations that accommodate lattice mismatch, the dislocation structures observed here increase the mismatch strain energy. Stop-action observations of the dynamically evolving atomic structures indicate that during deposition on the (111) surface of a fcc lattice, adatoms may occupy either fcc sites or hcp sites. This results in the random formation of fcc and hcp domains, with dislocations at the domain boundaries. These dislocations enable atoms to undergo a shift from fcc to hcp sites, or vice versa. These shifts lead to missing atoms, and therefore a later deposited layer can have missing planes compared to a previously deposited layer. This dislocation formation mechanism can create tensile stress in fcc films. The probability that such dislocations are formed was found to quickly diminish under energetic deposition conditions.

FORTRAN (2004--Zhou-X-W--Au--FORTRAN--ipr1)
Notes: These are the original files sent by X.W. Zhou (Sandia National Laboratory) and posted with his permission. C.A. Becker (NIST) modified create.f to include the reference in the generated potential files and the EAM.input file for this composition. These files can be used to generate alloy potentials for Cu, Ag, Au, Ni, Pd, Pt, Al, Pb, Fe, Mo, Ta, W, Mg, Co, Ti, and Zr by editing EAM.input. However, as addressed in the reference, these potentials were not designed for use with metal compounds.
File(s): superseded


LAMMPS pair_style eam/alloy (2004--Zhou-X-W--Au--LAMMPS--ipr1)
See Computed Properties
Notes: This file was generated by C.A. Becker (NIST) from create.f and posted with X.W. Zhou's (Sandia National Laboratory) permission.
File(s): superseded


FORTRAN (2004--Zhou-X-W--Au--FORTRAN--ipr2)
Notes: The file Zhou04_create_v2.f is an updated version of create.f modified by L.M. Hale (NIST) following advice from X.W. Zhou (Sandia National Laboratory). This version removes spurious fluctuations in the tabulated functions of the original potential files caused by single/double precision floating point number conflicts.
File(s):
LAMMPS pair_style eam/alloy (2004--Zhou-X-W--Au--LAMMPS--ipr2)
See Computed Properties
Notes: This file was generated by L.M. Hale from Zhou04_create_v2.f on 13 April 2018 and posted with X.W. Zhou's (Sandia National Laboratory) permission. This version corrects an issue with spurious fluctuations in the tabulated functions.
File(s):
See Computed Properties
Notes: Listing found at https://openkim.org. This KIM potential is based on the files from 2004--Zhou-X-W--Au--LAMMPS--ipr1.
Link(s):
See Computed Properties
Notes: Listing found at https://openkim.org. This KIM potential is based on the files from 2004--Zhou-X-W--Au--LAMMPS--ipr2.
Link(s):
Citation: B.-J. Lee, J.-H. Shim, and M.I. Baskes (2003), "Semiempirical atomic potentials for the fcc metals Cu, Ag, Au, Ni, Pd, Pt, Al, and Pb based on first and second nearest-neighbor modified embedded atom method", Physical Review B, 68(14), 144112. DOI: 10.1103/physrevb.68.144112.
Abstract: Modified embedded atom method (MEAM) potentials for fcc elements Cu, Ag, Au, Ni, Pd, Pt, Al, and Pb have been newly developed using the original first nearest-neighbor MEAM and the recently developed second nearest-neighbor MEAM formalisms. It was found that the original MEAM potentials for fcc elements show some critical shortcomings such as structural instability and incorrect surface reconstructions on (100), (110), and/or (111) surfaces. The newly developed MEAM potentials solve most of the problems and describe the bulk properties (elastic constants, structural energy differences), point defect properties (vacancy and interstitial formation energy and formation volume, activation energy of vacancy diffusion), planar defect properties (stacking fault energy, surface energy, surface relaxation and reconstruction), and thermal properties (thermal expansion coefficients, specific heat, melting point, heat of melting) of the fcc elements considered, in good agreement with relevant experimental information. It has been shown that in the MEAM the degree of many-body screening (Cmin) is an important material property and that structural stability at finite temperatures should be included as a checkpoint during development of semiempirical potentials.

LAMMPS pair_style meam (2003--Lee-B-J--Au--LAMMPS--ipr1)
See Computed Properties
Notes: These potential files were obtained from http://cmse.postech.ac.kr/home_2nnmeam, accessed Nov 9, 2020.
File(s):
See Computed Properties
Notes: Listing found at https://openkim.org.
Link(s):
Citation: K.W. Jacobsen, P. Stoltze, and J.K. Nørskov (1996), "A semi-empirical effective medium theory for metals and alloys", Surface Science, 366(2), 394-402. DOI: 10.1016/0039-6028(96)00816-3.
Abstract: A detailed derivation of the simplest form of the effective medium theory for bonding in metallic systems is presented, and parameters for the fcc metals Ni, Pd, Pt, Cu, Ag and Au are given. The derivation of parameters is discussed in detail to show how new parameterizations can be made. The method and the parameterization is tested for a number of surface and bulk problems. In particular we present calculations of the energetics of metal atoms deposited on metal surfaces. The calculated energies include heats of adsorption, energies of overlayers, both pseudomorphic and relaxed, as well as energies of atoms alloyed into the first surface layer.

Citation: J.B. Adams, S.M. Foiles, and W.G. Wolfer (1989), "Self-diffusion and impurity diffusion of fcc metals using the five-frequency model and the Embedded Atom Method", Journal of Materials Research, 4(1), 102-112. DOI: 10.1557/jmr.1989.0102.
Abstract: The activation energies for self-diffusion of transition metals (Au, Ag, Cu, Ni, Pd, Pt) have been calculated with the Embedded Atom Method (EAM); the results agree well with available experimental data for both mono-vacancy and di-vacancy mechanisms. The EAM was also used to calculate activation energies for vacancy migration near dilute impurities. These energies determine the atomic jump frequencies of the classic "five-frequency formula," which yields the diffusion rates of impurities by a mono-vacancy mechanism. These calculations were found to agree fairly well with experiment and with Neumann and Hirschwald's "Tm" model.

See Computed Properties
Notes: auu6.txt was obtained from http://enpub.fulton.asu.edu/cms/ potentials/main/main.htm and posted with the permission of J.B. Adams. The name of the file was retained, even though the header information lists the potential as 'universal 4.' This file is compatible with the "pair_style eam" format in LAMMPS (19Feb09 version).
File(s):
See Computed Properties
Notes: Listing found at https://openkim.org. This KIM potential is based on the same files as 1989--Adams-J-B--Au--LAMMPS--ipr1.
Link(s):
Citation: G.J. Ackland, G. Tichy, V. Vitek, and M.W. Finnis (1987), "Simple N-body potentials for the noble metals and nickel", Philosophical Magazine A, 56(6), 735-756. DOI: 10.1080/01418618708204485.
Abstract: Using the approach of Finnis and Sinclair, N-body potentials for copper, silver, gold and nickel have been constructed. The total energy is regarded as consisting of a pair-potential part and a many body cohesive part. Both these parts are functions of the atomic separations only and are represented by cubic splines, fitted to various bulk properties. For the noble metals, the pair-potentials were fitted at short range to pressure-volume relationships calculated by Christensen and Heine so that interactions at separations smaller than that of the first-nearest neighbours can be treated in this scheme. Using these potentials, point defects, surfaces (including the surface reconstructions) and grain boundaries have been studied and satisfactory agreement with available experimental data has been found.

Moldy FS (1987--Ackland-G-J--Au--MOLDY--ipr1)
Notes: The parameters in au.moldy were obtained from http://homepages.ed.ac.uk/graeme/moldy/moldy.html and posted with the permission of G.J. Ackland.
File(s):
LAMMPS pair_style eam/fs (1987--Ackland-G-J--Au--LAMMPS--ipr1)
See Computed Properties
Notes: This conversion was performed from G.J. Ackland's parameters by M.I. Mendelev. Conversion checks from M.I. Mendelev can be found in the conversion_check.pdf. These files were posted on 30 June 2009 with the permission of G.J. Ackland and M.I. Mendelev. These potentials are not designed for simulations of radiation damage. Update 19 July 2021: The contact email in the file's header has been changed.
File(s):
LAMMPS pair_style eam/fs (1987--Ackland-G-J--Au--LAMMPS--ipr2)
See Computed Properties
Notes: A new conversion to LAMMPS performed by G.J. Ackland was submitted on 10 Oct. 2017. This version adds close-range repulsion for radiation studies.
File(s):
See Computed Properties
Notes: Listing found at https://openkim.org. This KIM potential is based on the files from 1987--Ackland-G-J--Au--LAMMPS--ipr1.
Link(s):
See Computed Properties
Notes: Listing found at https://openkim.org. This KIM potential is based on the files from 1987--Ackland-G-J--Au--LAMMPS--ipr2.
Link(s):
Citation: S.M. Foiles, M.I. Baskes, and M.S. Daw (1986), "Embedded-atom-method functions for the fcc metals Cu, Ag, Au, Ni, Pd, Pt, and their alloys", Physical Review B, 33(12), 7983-7991. DOI: 10.1103/physrevb.33.7983.
Abstract: A consistent set of embedding functions and pair interactions for use with the embedded-atom method [M.S. Daw and M. I. Baskes, Phys. Rev. B 29, 6443 (1984)] have been determined empirically to describe the fcc metals Cu, Ag, Au, Ni, Pd, and Pt as well as alloys containing these metals. The functions are determined empirically by fitting to the sublimation energy, equilibrium lattice constant, elastic constants, and vacancy-formation energies of the pure metals and the heats of solution of the binary alloys. The validity of the functions is tested by computing a wide range of properties: the formation volume and migration energy of vacancies, the formation energy, formation volume, and migration energy of divacancies and self-interstitials, the surface energy and geometries of the low-index surfaces of the pure metals, and the segregation energy of substitutional impurities to (100) surfaces.

See Computed Properties
Notes: This file was taken from the August 22, 2018 LAMMPS distribution.
File(s):
See Computed Properties
Notes: Listing found at https://openkim.org. This KIM potential is based on the same files as 1986--Foiles-S-M--Au--LAMMPS--ipr1.
Link(s):
 
Citation: K.W. Jacobsen, P. Stoltze, and J.K. Nørskov (1996), "A semi-empirical effective medium theory for metals and alloys", Surface Science, 366(2), 394-402. DOI: 10.1016/0039-6028(96)00816-3.
Abstract: A detailed derivation of the simplest form of the effective medium theory for bonding in metallic systems is presented, and parameters for the fcc metals Ni, Pd, Pt, Cu, Ag and Au are given. The derivation of parameters is discussed in detail to show how new parameterizations can be made. The method and the parameterization is tested for a number of surface and bulk problems. In particular we present calculations of the energetics of metal atoms deposited on metal surfaces. The calculated energies include heats of adsorption, energies of overlayers, both pseudomorphic and relaxed, as well as energies of atoms alloyed into the first surface layer.

Notes: EMT uses a global cutoff, and this cutoff depends on the largest atom in the simulation. For single-element simulations, please use the single-element parametrizations, as they use a cutoff more appropriate for the element in question (and are marginally faster).

 
Citation: S.M.A.A. Alvi, A. Faiyad, M.A.M. Munshi, M. Motalab, M.M. Islam, and S. Saha (2022), "Cyclic and tensile deformations of Gold–Silver core shell systems using newly parameterized MEAM potential", Mechanics of Materials, 169, 104304. DOI: 10.1016/j.mechmat.2022.104304.
Abstract: Gold–Silver (Au-Ag) core-shell nanostructures have significant applicability in stretchable and biocompatible electronics where endurance under high tensile and cyclic loading is a requirement. This work, for the first time, quantitatively investigates the role of dislocations and defect interaction governing the mechanical behavior of Au-Ag and Ag-Au Core-shell nanostructures under tensile and cyclic loading using molecular dynamics (MD) simulation. For accurate representation of the underlying physics, a novel modified embedded atomic model (MEAM) interatomic potential for pristine Au, Ag and their alloys is parameterized through two different density functional theory (DFT) schemes. Using the new potential for MD simulations, the cyclic loading properties of pristine and core-shell nanowires (NWs) in a strain range of -15%-15% for 10 cycles are conducted. The tensile behavior of pristine and core-shell NWs is also explored for temperatures between 300 K and 600 K. A comparative analysis between Core-shell structures and their pristine counterparts are carried out. Our results suggest that Ag-Au Core-shell NW exhibit superior stress-strain reversibility under cyclic loading among the structures examined. Ag-Au exhibit the highest dislocation formation and near-complete annihilation of defects consistently. Au-Ag also present improved cyclic loading properties than its pristine counterparts. For tensile loading, all four structures exhibited deterioration in strength with increasing temperature. Thermal softening is observed to be more prominent in Au-Ag core-shell NWs compared to Ag-Au. Our work lays out a foundation for exploration of mechanical properties of Au-Ag systems using the MEAM potential which will help design components for stretchable electronics and creates a pathway for further exploration of similar binary alloy systems.

See Computed Properties
Notes: These files were provided by Sourav Saha on May 6, 2022 and posted with his permission.
File(s):
 
Citation: X.W. Zhou, R.A. Johnson, and H.N.G. Wadley (2004), "Misfit-energy-increasing dislocations in vapor-deposited CoFe/NiFe multilayers", Physical Review B, 69(14), 144113. DOI: 10.1103/physrevb.69.144113.
Abstract: Recent molecular dynamics simulations of the growth of [Ni0.8Fe0.2/Au] multilayers have revealed the formation of misfit-strain-reducing dislocation structures very similar to those observed experimentally. Here we report similar simulations showing the formation of edge dislocations near the interfaces of vapor-deposited (111) [NiFe/CoFe/Cu] multilayers. Unlike misfit dislocations that accommodate lattice mismatch, the dislocation structures observed here increase the mismatch strain energy. Stop-action observations of the dynamically evolving atomic structures indicate that during deposition on the (111) surface of a fcc lattice, adatoms may occupy either fcc sites or hcp sites. This results in the random formation of fcc and hcp domains, with dislocations at the domain boundaries. These dislocations enable atoms to undergo a shift from fcc to hcp sites, or vice versa. These shifts lead to missing atoms, and therefore a later deposited layer can have missing planes compared to a previously deposited layer. This dislocation formation mechanism can create tensile stress in fcc films. The probability that such dislocations are formed was found to quickly diminish under energetic deposition conditions.

FORTRAN (2004--Zhou-X-W--Cu-Ag-Au--FORTRAN--ipr1)
Notes: These are the original files sent by X.W. Zhou (Sandia National Laboratory) and posted with his permission. C.A. Becker (NIST) modified create.f to include the reference in the generated potential files and the EAM.input file for this composition. These files can be used to generate alloy potentials for Cu, Ag, Au, Ni, Pd, Pt, Al, Pb, Fe, Mo, Ta, W, Mg, Co, Ti, and Zr by editing EAM.input. However, as addressed in the reference, these potentials were not designed for use with metal compounds.
File(s): superseded


LAMMPS pair_style eam/alloy (2004--Zhou-X-W--Cu-Ag-Au--LAMMPS--ipr1)
See Computed Properties
Notes: This file was generated by C.A. Becker (NIST) from create.f and posted with X.W. Zhou's (Sandia National Laboratory) permission.
File(s): superseded


FORTRAN (2004--Zhou-X-W--Cu-Ag-Au--FORTRAN--ipr2)
Notes: The file Zhou04_create_v2.f is an updated version of create.f modified by L.M. Hale (NIST) following advice from X.W. Zhou (Sandia National Laboratory). This version removes spurious fluctuations in the tabulated functions of the original potential files caused by single/double precision floating point number conflicts.
File(s):
LAMMPS pair_style eam/alloy (2004--Zhou-X-W--Cu-Ag-Au--LAMMPS--ipr2)
See Computed Properties
Notes: This file was generated by L.M. Hale from Zhou04_create_v2.f on 13 April 2018 and posted with X.W. Zhou's (Sandia National Laboratory) permission. This version corrects an issue with spurious fluctuations in the tabulated functions.
File(s):
See Computed Properties
Notes: Listing found at https://openkim.org. This KIM potential is based on the files from 2004--Zhou-X-W--Cu-Ag-Au--LAMMPS--ipr2.
Link(s):
Citation: G.J. Ackland, and V. Vitek (1990), "Many-body potentials and atomic-scale relaxations in noble-metal alloys", Physical Review B, 41(15), 10324-10333. DOI: 10.1103/physrevb.41.10324.
Abstract: We derive empirical many-body potentials for noble-metal alloy systems in the framework of the Finnis-Sinclair model [Philos. Mag. A 50, 45 (1984)] which is based on a second-moment approximation to the tight-binding density of states for transition metals [F. Cyrot, J. Phys. Chem. Solids 29, 1235 (1968)]. The most important extension of the model is a simple incorporation of interspecies interactions which involves fitting the alloying energies. The importance of properly accounting for the local atomic relaxations when constructing the potentials is emphasized. The observed principal features of the phase diagrams of the alloys are all well reproduced by this scheme. Furthermore, reasonable concentration dependences of the alloy lattice parameter and elastic constants are obtained. This leads us to suggest that fine details of the electronic structure may be less important in determining atomic structures than are more global parameters such as atomic sizes and binding energies.

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Notes: These files were provided by Jyri Kimari on 8 May 2023. The code_and_tests.zip folder contains the fortran program and input file used to generate the eam.fs file, plots of the potential functions,and plots of the binary alloying energies. For the alloying energies, two sizes were investigated (256 atoms and 32000 atoms) which respectively agree with the local and hydrostatic configurational sampling models (LCSM and HCSM) reported in the paper.
File(s):
 
Citation: J.B. Adams, S.M. Foiles, and W.G. Wolfer (1989), "Self-diffusion and impurity diffusion of fcc metals using the five-frequency model and the Embedded Atom Method", Journal of Materials Research, 4(1), 102-112. DOI: 10.1557/jmr.1989.0102.
Abstract: The activation energies for self-diffusion of transition metals (Au, Ag, Cu, Ni, Pd, Pt) have been calculated with the Embedded Atom Method (EAM); the results agree well with available experimental data for both mono-vacancy and di-vacancy mechanisms. The EAM was also used to calculate activation energies for vacancy migration near dilute impurities. These energies determine the atomic jump frequencies of the classic "five-frequency formula," which yields the diffusion rates of impurities by a mono-vacancy mechanism. These calculations were found to agree fairly well with experiment and with Neumann and Hirschwald's "Tm" model.

Notes: Cross-element interactions were only considered for small (1-2%) impurity concentrations and use a generalized universal function.

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Notes: These files were obtained from http://enpub.fulton.asu.edu/cms/ potentials/main/main.htm and posted with the permission of J.B. Adams. The name of the file was retained, even though the header information lists the potential as 'universal 4.' Except for the first comment line, "cuu6.txt" is identical to "Cu_u6.eam" in the August 22, 2018 LAMMPS distribution.
File(s):
Citation: S.M. Foiles, M.I. Baskes, and M.S. Daw (1986), "Embedded-atom-method functions for the fcc metals Cu, Ag, Au, Ni, Pd, Pt, and their alloys", Physical Review B, 33(12), 7983-7991. DOI: 10.1103/physrevb.33.7983.
Abstract: A consistent set of embedding functions and pair interactions for use with the embedded-atom method [M.S. Daw and M. I. Baskes, Phys. Rev. B 29, 6443 (1984)] have been determined empirically to describe the fcc metals Cu, Ag, Au, Ni, Pd, and Pt as well as alloys containing these metals. The functions are determined empirically by fitting to the sublimation energy, equilibrium lattice constant, elastic constants, and vacancy-formation energies of the pure metals and the heats of solution of the binary alloys. The validity of the functions is tested by computing a wide range of properties: the formation volume and migration energy of vacancies, the formation energy, formation volume, and migration energy of divacancies and self-interstitials, the surface energy and geometries of the low-index surfaces of the pure metals, and the segregation energy of substitutional impurities to (100) surfaces.

Notes: The cross-elemental interactions use a universal function designed to show trends across the metals and is not fitted for revealing compounds.

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Notes: These files were taken from the August 22, 2018 LAMMPS distribution.
File(s):
 
Citation: S. Starikov, I. Gordeev, Y. Lysogorskiy, L. Kolotova, and S. Makarov (2020), "Optimized interatomic potential for study of structure and phase transitions in Si-Au and Si-Al systems", Computational Materials Science, 184, 109891. DOI: 10.1016/j.commatsci.2020.109891.
Abstract: Metal-semiconductor nanostructures are key objects for multifunctional electronics and optical design. We report a new interatomic potential for atomistic simulation of a ternary Si-Au-Al system. The development procedure was based on the force-matching method that allowed us to create the potential without use of experimental data at the fitting. Extensive validation including elastic, thermophysical and defect properties demonstrates a wide range of the potential applicability. Special attention was paid to the description of the silicon-metal alloys in liquid and amorphous states. We used the new potential for study of crystallization and glass transition in the undercooled melt. The simulation results revealed the beneficial conditions for the formation of the unique metal-semiconductor nanocrystalline structure, which is highly important for various applications in the field of nanophotonics.

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Notes: This file was sent by Sergei Starikov (Joint Institute for High Temperatures, Russia) on 30 June 2020 and posted with his permission.
File(s): superseded


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Notes: This file was sent by Sergei Starikov (Joint Institute for High Temperatures, Russia) on 6 Dec 2020. Dr. Starikov notes that "In the updated version of the potential, I fixed a bug leading to non-physical minima on E-V dependencies at low density of pure Si. The modification of the potential consists of a little change in the slope of the Embedded function F(rho) near rho = 0 for Si. This avoids the appearance of global minima for simulations of extremely expanded crystal lattices."
File(s):
 
Citation: V.S. Guthikonda, and R.S. Elliott (2009), "An effective interaction potential model for the shape memory alloy AuCd", Continuum Mechanics and Thermodynamics, 21(4), 269-295. DOI: 10.1007/s00161-009-0109-1.
Abstract: The unusual properties of shape memory alloys (SMAs) result from a lattice level martensitic transformation (MT) corresponding to an instability of the SMAs crystal structure. Currently, there exists a shortage of material models that can capture the details of lattice level MTs occurring in SMAs and that can be used for efficient computational investigations of the interaction between MTs and larger-scale features found in typical materials. These larger-scale features could include precipitates, dislocation networks, voids, and even cracks. In this article, one such model is developed for the SMA AuCd. The model is based on effective interaction potentials (EIPs). These are atomic interaction potentials that are explicit functions of temperature. In particular, the Morse pair potential is used and its adjustable coefficients are taken to be temperature dependent. An extensive exploration of the Morse pair potential is performed to identify an appropriate functional form for the temperature dependence of the potential parameters. A fitting procedure is developed for the EIPs that matches, at suitable temperatures, the stress-free equilibrium lattice parameters, instantaneous bulk moduli, cohesive energies, thermal expansion coefficients, and heat capacities of FCC Au, HCP Cd, and the B2 cubic austenite phase of the Au-47.5at%Cd alloy. The resulting model is explored using branch-following and bifurcation techniques. A hysteretic temperature-induced MT between the B2 cubic and B19 orthorhombic crystal structures is predicted. This is the behavior that is observed in the real material. In addition to reproducing the important properties mentioned above, the model predicts, to reasonable accuracy, the transformation strain tensor and captures the latent heat and thermal hysteresis to within an order of magnitude.
Citation: V.S. Guthikonda, and R.S. Elliott (2010), "Erratum to: An effective interaction potential model for the shape memory alloy AuCd", Continuum Mechanics and Thermodynamics, 23(2), 177-183. DOI: 10.1007/s00161-010-0169-2.

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Notes: Listing found at https://openkim.org.
Link(s):
 
Citation: A. Gola, and L. Pastewka (2018), "Embedded atom method potential for studying mechanical properties of binary Cu–Au alloys", Modelling and Simulation in Materials Science and Engineering, 26(5), 055006. DOI: 10.1088/1361-651x/aabce4.
Abstract: We present an embedded atom method (EAM) potential for the binary Cu–Au system. The unary phases are described by two well-tested unary EAM potentials for Cu and Au. We fitted the interaction between Cu and Au to experimental properties of the binary intermetallic phases Cu3Au, CuAu and CuAu3. Particular attention has been paid to reproducing stacking fault energies in order to obtain a potential suitable for studying deformation in this binary system. The resulting energies, lattice constant, elastic properties and melting points are in good agreement with available experimental data. We use nested sampling to show that our potential reproduces the phase boundaries between intermetallic phases and the disordered face-centered cubic solid solution. We benchmark our potential against four popular Cu–Au EAM parameterizations and density-functional theory calculations.

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Notes: Listing found at https://openkim.org.
Link(s):
 
Citation: C.J. O'Brien, C.M. Barr, P.M. Price, K. Hattar, and S.M. Foiles (2017), "Grain boundary phase transformations in PtAu and relevance to thermal stabilization of bulk nanocrystalline metals", Journal of Materials Science, 53(4), 2911-2927. DOI: 10.1007/s10853-017-1706-1.
Abstract: There has recently been a great deal of interest in employing immiscible solutes to stabilize nanocrystalline microstructures. Existing modeling efforts largely rely on mesoscale Monte Carlo approaches that employ a simplified model of the microstructure and result in highly homogeneous segregation to grain boundaries. However, there is ample evidence from experimental and modeling studies that demonstrates segregation to grain boundaries is highly non-uniform and sensitive to boundary character. This work employs a realistic nanocrystalline microstructure with experimentally relevant global solute concentrations to illustrate inhomogeneous boundary segregation. Experiments quantifying segregation in thin films are reported that corroborate the prediction that grain boundary segregation is highly inhomogeneous. In addition to grain boundary structure modifying the degree of segregation, the existence of a phase transformation between low and high solute content grain boundaries is predicted. In order to conduct this study, new embedded atom method interatomic potentials are developed for Pt, Au, and the PtAu binary alloy.

LAMMPS pair_style eam/alloy (2017--OBrien-C-J--Pt-Au--LAMMPS--ipr1)
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Notes: This file was submitted by Dr. C.J. O'Brien (Sandia National Laboratories) on 07 May 2018. Dr. O'Brien also provided a description of the potential and its implementation, which can be found in OBrien-SI.pdf.
File(s):
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Notes: Listing found at https://openkim.org. This KIM potential is based on the files from 2017--OBrien-C-J--Pt-Au--LAMMPS--ipr1.
Link(s):
 
Citation: G. Wang, Y. Xu, P. Qian, and Y. Su (2021), "ADP potential for the Au-Rh system and its application in element segregation of nanoparticles", Computational Materials Science, 186, 110002. DOI: 10.1016/j.commatsci.2020.110002.
Abstract: A new ADP potential for the Au-Rh system was developed by fitting to a database of experimental and first principle data, and the validity of the potential was tested. Then, the element segregation of Au-Rh nanoparticles was studied by Monte Carlo simulation using this potential. The results show that the preferential segregation behavior of atoms in Au-Rh nanoparticles is not affected by the particle size. On the surface, due to the large surface energy difference between Au and Rh, the element segregation is mainly induced by the surface energy, and Au atoms preferentially occupy the lower coordination sites. In the body, Au atoms tend to occupy the sites with small local pressure to release strain energy, while the whole system tends to reduce the interface area to decrease the interface energy. The element segregation is primarily induced by the strain energy, and the interface energy also participates in the competition. The final structure is the result of the competition between strain energy and interface energy.

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Notes: This file was provided by Gang Wang (University of Science and Technology Beijing) on August 18, 2020 and posted with his permission.
File(s):
 
Citation: S.V. Starikov, N.Y. Lopanitsyna, D.E. Smirnova, and S.V. Makarov (2018), "Atomistic simulation of Si-Au melt crystallization with novel interatomic potential", Computational Materials Science, 142, 303-311. DOI: 10.1016/j.commatsci.2017.09.054.
Abstract: In this work we studied crystallization of the liquid Si-Au system at rapid cooling. For this purpose we performed atomistic simulation with novel interatomic potential. Results of the simulations showed that crystallization proceeds in different ways for pure silicon and Si-Au melt. For the studied binary system, the main factor limiting crystallization is diffusion of Au atoms in the liquid state. Threshold cooling rate for crystallization significantly depends on the Au content.

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Notes: These files were sent by Dr. Sergey Starikov (Joint Institute for High Temperatures, Russia) on 6 November 2017 and posted with his permission.
File(s): superseded


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Notes: A new implementation was sent by Dr. Sergey Starikov on 1 October 2018 and posted with his permission with the following comments: "The old version of the potential (above) could not correctly describe several dense structures of silicon (like fcc and hcp) as the explored values of density (rho) exceeded those tabulated. As such, many structures incorrectly had energy lower than diamond lattice. This version fixes the bug by increasing the maximum tabulated rho from 1.0 to 2.0, and gives the right hierarchy of the crystal structures."
File(s):
Date Created: October 5, 2010 | Last updated: May 12, 2023