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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
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File(s): superseded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--Pt--LAMMPS--ipr1)
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File(s): superseded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
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--Pt--LAMMPS--ipr2)
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):
Citation: G.J. Ackland (1990), "unpublished".

Moldy FS
Notes: The parameters in pt.moldy were obtained from <a href="http://homepages.ed.ac.uk/graeme/moldy/moldy.html" class="external">http://homepages.ed.ac.uk/graeme/moldy/moldy.html </a> and posted with the permission of G.J. Ackland.
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.

LAMMPS pair_style eam (1989--Adams-J-B--Pt--LAMMPS--ipr1)
Notes: ptu6.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):
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.

LAMMPS pair_style eam (1986--Foiles-S-M--Pt--LAMMPS--ipr1)
Notes: This file was taken from the August 22, 2018 LAMMPS distribution.
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(01), 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.

LAMMPS pair_style eam (1989--Adams-J-B--Ag-Au-Cu-Ni-Pd-Pt--LAMMPS--ipr1)
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.

LAMMPS pair_style eam (1986--Foiles-S-M--Ag-Au-Cu-Ni-Pd-Pt--LAMMPS--ipr1)
Notes: These files were taken from the August 22, 2018 LAMMPS distribution.
File(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)
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):
Date Created: October 5, 2010 | Last updated: October 05, 2018