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Modeling defects and plasticity in MgSiO3 post-perovskite: Part 2—screw and edge [100] dislocationстатья
- Авторы: Goryaeva A.M., Carrez P., Cordier P.
- Журнал: Physics and Chemistry of Minerals
- Год издания: 2015
- Издательство: Springer Verlag
- Местоположение издательства: Germany
- DOI: 10.1007/s00269-015-0763-8
- Аннотация: In this study, we propose a full atomistic study of [100] dislocations in MgSiO3 post-perovskite based on the pairwise potential parameterized by Oganov et al. (Phys Earth Planet Inter 122:277–288, 2000) for MgSiO3 perovskite. We model screw dislocations to identify planes where they glide easier. We show that despite a small tendency to core spreading in {011}, [100] screw dislocations glide very easily (Peierls stress of 1 GPa) in (010) where only Mg–O bonds are to be sheared. Crossing the Si-layers results in a higher lattice friction as shown by the Peierls stress of [100](001): 17.5 GPa. Glide of [100] screw dislocations in {011} appears also to be highly unfavorable. Whatever the planes, (010), (001) or {011}, edge dislocations are characterized by a wider core (of the order of 2b). Contrary to screw character, they bear negligible lattice friction (0.1 GPa) for each slip system. The layered structure of post-perovskite results in a drastic reduction in lattice friction opposed to the easiest slip systems compared to perovskite.
- Добавил в систему: Еремин Николай Николаевич