RheoMan: a five-year, ERC-funded (Advanced Grant), project to model the rheology of the Earth's mantle

Dec 19, 2013 Publication in Modelling and Simulation in Materials Science and Engineering General

K. Gouriet, P. Carrez & P. Cordier (2013)  Modelling [100] and [010] screw dislocations in MgSiO3 perovskite based on the Peierls-Nabarro-Galerkin model.

has been accepted today for publication in Modelling and Simulation in Materials Science and Engineering.

Abstract

In this study, we model the core structure of screw dislocations with [100] and [010] Burgers vector in MgSiO3 perovskite, in the pressure range of Earth’s lower mantle (25-130 GPa). We use a generalized Peierls-Nabarro model, called Peierls-Nabarro-Galerkin, based on generalized staking fault energy calculations. These stacking fault energy calculations are performed using a pairwise potential parameterization and compared to ab initio results. The results of Peierls-Nabarro-Galerkin calculations demonstrate that [100] dislocation and [010] are respectively characterized by a planar core spread in (010) and (100) planes. Ours results emphasize the role of [100](010) and [010](100) slip systems in the deformation mechanism of MgSiO3 perovskite. Furthermore, we validate the use of pairwise potential for further study of mechanical properties of such mineral at atomic scale.