Effects of interface dynamics and layered structure on nanoformed gold films investigated using molecular dynamics simulation

Abstract

In this work, a molecular dynamics simulation of the nanoforming process of single-crystal gold (Au) films utilising the many-body tight-binding potential approach is presented. The effects of the imprint depth and layered interface structure are evaluated in terms of atomic trajectories, potential energy, slip vectors and loading force. The simulation results show that for the Au thin film, the deformation proceeds along the {1 1 1} and {} close-packed planes, extending to the interior. The potential energy of Au films significantly increases with increasing mould displacement during the filling process due to the film dramatic deformation. During nanoforming, the plastic deformation of Au films starts and, consequently, since the yield strength is achieved on fcc metal structures slip planes, a slip band appears at 45° along the dislocation slip direction. The magnitude and distribution of the slip vector significantly depends on the layer arrangement and initial structure of a film. The twin boundary defect has been observed in studies of Au films with the Au–Au vertical arrangement during nanoforming process caused by high-energy atoms in the defect structure of Au films that all are significantly distributed along the direction of the slip plane.