Simulation of dislocation nucleation and motion in single crystal magnesium oxide by a field theory

This paper presents a multiscale field theory and its application in modeling and simulation of the phenomena that take place at atomic scale. Atomistic formulation of a multiscale field theory is introduced. The governing equations for problems with a given temperature are derived. We have modeled and simulated the nucleation and motion of dislocations and the formation of plastic deformation in a nanoscale ionic material MgO. The mechanism of deformation as well as the evolution of the stress has been elucidated. Results are compared with those from molecular dynamics simulations.