Atomistic Simulation of Formation and Structure of Misfit Dislocations

Abstract

ABSTRACTIn our earlier work [1] we had reported first theoretical observations of the spontaneous formation of 60° and 90° misfit dislocations in Au/Ni (15.9% mismatch) systems for the (111) and (001) interfaces respectively. Here, we present the analysis of the evolution of the dislocation configuration as it evolves from a highly strained coherent Au film. The driving force for the formation of these misfit dislocations was the reduction in the config-urational energy during the iterative relaxation of the atoms. A finely stepped energy minimization technique was developed to relax the high energy configuration. Misfit dislocations were also obtained for low misfit systems (Pd/Ni - 10% and Pd/Cu - 7.76%), but a modified approach, which is described here, was used for these systems which shows an energy barrier to the formation of dislocations in the low misfit systems.