Dislocation modeling in calcium silicate perovskite based on the Peierls-Nabarro model

Abstract

In this study, we propose a study of dislocations and plasticity in CaSiO3 perovskite based on the Peierls-Nabarro modeling using the generalized stacking fault (GSF) results as a starting model. The GSF are determined from first-principle calculations using the VASP code. The dislocation properties such as planar core spreading and Peierls stresses are determined for the four possible slip systems: 〈110〉 {11̅0}, 〈100〉 {011}, 〈110〉 {001}, and 〈100〉 {001} and at 0, 30, and 100 GPa. We find that 〈110〉 {11̅0} is the easiest slip system, but more surprisingly, we show that it bears no Peierls friction, even at the higher pressure. The reasons lie in the ability of these dislocations to split into partial dislocations and in the nature of the stacking fault associated with it.