Peierls-Nabarro model for dislocations in MgSiO3 post-perovskite calculated at 120 GPa from first principles

Ph. Carrez (1) , D. Ferré (1) , P Cordier (1)

1 LSPES - Laboratoire de structures et propriétés de l'état solide - UMR 8008

We present here the first numerical modelling of dislocations in MgSiO3 post-perovskite at 120 GPa. The dislocation core structures and properties are calculated through the Peierls-Nabarro model 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 following slip systems: [100](010), [100](001), [100](011), [001](010), [001](110), [001](100), [010](100), [010](001), ½[110](001) and ½[110]( ). Our results confirm that the MgSiO3 post-perovskite is a very anisotropic phase with a plasticity dominated by dislocation glide in the (010) plane

Mots clés: Physical Sciences

Ph. Carrez, D. Ferré, P Cordier. Peierls-Nabarro model for dislocations in MgSiO3 post-perovskite calculated at 120 GPa from first principles. Philosophical Magazine, 2007, 87 (22), pp.3229-3247. ⟨10.1080/14786430701268914⟩. ⟨hal-00513824⟩