Theoretical calculations of characters and stability of glide dislocations in zinc sulfide

Abstract

Generalized stacking fault energies were calculated to understand dislocation characters and stability in zinc sulfide (ZnS) by using the density functional theory calculations. Peierls stresses and dislocation self energies were estimated for perfect and dissociated dislocations on glide-set and shuffle-set planes in ZnS in a framework of the PeierlsNabarro model. It was found that Peierls stresses of the shuffle-set dislocations are smaller than those of the glide-set dislocations whereas dislocation self energies of the shuffle set are larger. It is experimentally known that the dissociated glide-set dislocations can be more easily formed and multiplied during plastic deformation in darkness at room temperature. It is suggested that the glide-set dislocations can be primarily activated due to their lower self energy, in spite of their higher Peierls stress. [doi:10.2320/matertrans.M2018253]