Dislocations are the main lattice defects responsible for the strength and ductility of crystalline solids. The generation of new dislocations is an essential aspect of crystal defect physics, but a fundamental understanding of the mechanical conditions which lead to dislocation nucleation has remained elusive. Here, we present a nucleation criterion motivated from continuum thermomechanical considerations of a crystalline solid undergoing deformation, and demonstrate the criterion's ability to correctly predict dislocation nucleation via direct atomistic simulations. We further demonstrate that the commonly held notion of a nucleation criterion based on the magnitude of local stress components is incorrect.

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Keywords Atomistic simulation, Dislocation mechanics, Dislocation nucleation
Persistent URL dx.doi.org/10.1016/j.jmps.2004.01.007
Journal Journal of the Mechanics and Physics of Solids
Miller, R, & Acharya, A. (Amit). (2004). A stress-gradient based criterion for dislocation nucleation in crystals. Journal of the Mechanics and Physics of Solids, 52(7), 1507–1525. doi:10.1016/j.jmps.2004.01.007