Theoretical study of misfit dislocation in interface dynamics

Misfit dislocation is an important component of the semi-coherent interface. It is a line defect on interface, and strongly affects the structural and dynamical properties. In this work, we use an atomistic simulation method to study two representative dynamics of Pd/MgO interface: the fracture and slipping. The calculation shows that for both the two cases, misfit dislocation plays a critical role. However, the dislocation in the latter is much more important than in former, that it reduces the tensile stress (in fracture) for 26% but slip stress (in slipping) for three orders of magnitude. Also, some valuable parameters of misfit dislocation can be extracted from the atomistic simulation results by a simple derivation, such as the dislocation width, mass and velocity, which are determined as 14 Å, 0.46 awu/Å and 40 m/s in this work.