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. (C) 2007 Elsevier B.V. All rights reserved.