Peierls-Nabarro modelling of dislocations in MgO from ambient pressure to 100 GPa

We present in this study modelling of dislocation core properties in MgO as a function of pressure from ambient conditions to 100 GPa. The calculations are based on the Peierls-Nabarro model and we use first-principles calculations of the generalized stacking fault as input parameters. Our results confirm that 1/2 < 1 1 0 > {1 1 0} is the dominant slip system in MgO at ambient pressure and is easier than 1/2 < 1 1 0 > {1 0 0} as the pressure increases. Nevertheless, the 1/2 < 1 1 0 > {1 1 0} slip hardens with increasing pressure leading to a decrease in the difference in the Peierls stresses between 1/2 < 1 1 0 > {1 1 0} and 1/2 < 1 1 0 > {1 0 0}.