A new interatomic potential for copper solid–solution alloys with low Sb concentrations was proposed, based upon the Lennard-Jones pair formulation. Parameters for this new potential, σ and ε, were motivated by calculations of the Cu–Sb heat of solution and the strain field generated by a single substitutional impurity in monocrystalline copper, which was analyzed for dopant atoms with various atomic radii. A well-established embedded-atom method potential was used to model the copper host. The ε-parameter was derived for a range of σ-values by matching experimental values of the heat of solution. The strain field around a single dopant atom was then calculated for each set of calculated Lennard-Jones parameters. The final parameters of Cu–Sb interaction were selected so as to match the strain field corresponding to the atomic radius mismatch between Sb and Cu, and were compared with the Eshelby solutions, which were based upon the classical theory of elasticity. Using this new potential, it was shown - using molecular dynamics simulations - that the plastic deformation behavior of monocrystalline copper was affected by the characteristics of the strain field around the dopant atoms.

Interatomic Potential for Copper–Antimony in Dilute Solid–Solution Alloys and Application to Single Crystal Dislocation Nucleation. R.K.Rajgarhia, D.E.Spearot, A.Saxena: Computational Materials Science, 2009, 44[4], 1258-64