Peierls potential and kink-pair mechanism in high-pressure MgSiO sub(3) perovskite: An atomic scale study

The motion of [100](010) screw dislocations via a kink-pair mechanism is investigated in high-pressure MgSiO sub(3) perovskite by means of atomistic calculations and an elastic interaction model for kink nucleation. Atomistic calculations based on the nudged elastic band method provide the Peierls p...

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Bibliographic Details
Published in:Physical review. B 2016-01, Vol.93 (1)
Main Authors: Kraych, A, Carrez, Ph, Hirel, P, Clouet, E, Cordier, P
Format: Article
Language:English
Subjects:
Adjustment
Asymmetry
Condensed matter
Mathematical models
Nucleation
Peierls potential
Perovskites
Screw dislocations
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Summary:The motion of [100](010) screw dislocations via a kink-pair mechanism is investigated in high-pressure MgSiO sub(3) perovskite by means of atomistic calculations and an elastic interaction model for kink nucleation. Atomistic calculations based on the nudged elastic band method provide the Peierls potential, which is shown to be dynamically asymmetric and stress dependent. The elastic interaction model adjusted to match kink width computed atomistically, is used to evaluate the critical nucleation enthalpy. We demonstrate that the kink-pair mechanism in MgSiO sub(3) perovskite is controlled by the nucleation of kinks along the [100] screw dislocation.
ISSN:2469-9950
2469-9969
DOI:10.1103/PhysRevB.93.014103