Atomic-scale properties of jogs along 1/2 < 110 >{(1)over-bar10} edge dislocations in MgO

摘要

We report atomic-scale simulations of the structure and formation energies of jog pairs on 1/2 < 110 >{(1) over bar 10} edge dislocations in magnesium oxide (MgO). The atomic configurations of elementary jogs of height 1/4[(1) over bar 10] and super-jogs of height 1/2[(1) over bar 10] are fully characterized showing that stable jogs spread in {111}. Besides, our simulations confirm that elementary jogs carry an electric charge +/- q/2 where q is the charge of a Mg ion, while super-jogs are charge-neutral. The computation of the formation energy reveals the predominance of charged elementary jogs. This offers new insight into the mechanisms for dislocation climb in MgO. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.