Vacancy diffusion and irreversibility of deformations in the Lennard–Jones crystal

The effect of vacancy diffusion on the stress–strain data and on the structural transformations (dislocation, nanovoids and nanocracks formation) in a 2D LJ crystals is investigated numerically for a cyclic loading using a molecular statics approach. The results are compared against the case of a fixed vacancy. It is shown that the migration of the latter leads to irreversible deformations and structural transformations in the crystal. The convergence patterns of relaxation after each loading step confirm the occurrence of dislocations.