• Citation: L.K. Béland, C. Lu, Y.N. Osetskiy, G.D. Samolyuk, A. Caro, L. Wang, and R.E. Stoller (2016), "Features of primary damage by high energy displacement cascades in concentrated Ni-based alloys", Journal of Applied Physics, 119(8), 085901. DOI: 10.1063/1.4942533.
    Abstract: Alloying of Ni with Fe or Co has been shown to reduce primary damage production under ion irradiation. Similar results have been obtained from classical molecular dynamics simulations of 1, 10, 20, and 40 keV collision cascades in Ni, NiFe, and NiCo. In all cases, a mix of imperfect stacking fault tetrahedra, faulted loops with a 1/3⟨111⟩ Burgers vector, and glissile interstitial loops with a 1/2⟨110⟩ Burgers vector were formed, along with small sessile point defect complexes and clusters. Primary damage reduction occurs by three mechanisms. First, Ni-Co, Ni-Fe, Co-Co, and Fe-Fe short-distance repulsive interactions are stiffer than Ni-Ni interactions, which lead to a decrease in damage formation during the transition from the supersonic ballistic regime to the sonic regime. This largely controls final defect production. Second, alloying decreases thermal conductivity, leading to a longer thermal spike lifetime. The associated annealing reduces final damage production. These two mechanisms are especially important at cascades energies less than 40 keV. Third, at the higher energies, the production of large defect clusters by subcascades is inhibited in the alloys. A number of challenges and limitations pertaining to predictive atomistic modeling of alloys under high-energy particle irradiation are discussed.

    Notes: Prof. Beland notes that "The potential takes elemental Ni from 2004--Mishin-Y--Ni-Al and Co from 2012--Purja-Pun-G-P-Mishin-Y--Co and mixes them. We first applied the effective gauge transformation, and then fitted the cross-term as to reproduce the heat of mixing of Ni(x)-Co(1-x). The potential is very soft at short distances. In order to perform collision cascades, it should be overlaid to the ZBL potential, with an outer cutoff of 2.0 Angstroms."

  • LAMMPS pair_style eam/alloy (2016--Beland-L-K--Ni-Co--LAMMPS--ipr1)
    See Computed Properties
    Notes: This file was provided by Laurent Béland on 7 Nov 2019 and posted with his permission. Note: The EAM potential by itself is very soft at short distances. In order to perform collision cascades, use the hybrid style listed below.
    File(s):
  • LAMMPS pair_style hybrid/overlay zbl eam/alloy (2016--Beland-L-K--Ni-Co--LAMMPS--ipr2)
    See Computed Properties
    Notes: The eam file was provided by Laurent Béland on 7 Nov 2019 and posted with his permission. It is the same eam/alloy file as the above implementation. example.lammps.in provides an example of how to call the potential with the ZBL overlay applied.
    File(s):
Date Created: October 5, 2010 | Last updated: September 27, 2024