Dislocation modelling in Mg2SiO4 forsterite: an atomic-scale study based on the THB1 potential

作者：Mahendran S; Carrez P^*; Groh S; Cordier P

来源：Modelling and Simulation in Materials Science and Engineering, 2017, 25(5): 054002.

DOI：10.1088/1361-651X/aa6efa

• atomistic simulation
• ionic materials
• core shell model
• olivine
• dislocations
• crystal plasticity

Knowledge of the deformation mechanisms of (Mg,Fe)(2)SiO4 olivine is important for the understanding of flow and seismic anisotropy in the Earth's upper mantle. We report here a numerical modelling at the atomic scale of dislocation structures and slip system properties in Mg2SiO4 forsterite. Our study focuses on screw dislocations of [100] and [001] Burgers vectors. Computations are performed using the so-called THB1 empirical potential set for Mg2SiO4. Results of dislocation core structures highlight the primary importance of the (010) plane for [100] slip dislocations. For [001] dislocations, we confirm the occurrence of a stable narrow core that evolves into transient planar configurations to glide in (100) and (010). Such configurations suggest a locking-unlocking mechanism.

• 出版日期2017-7-1