Interaction of point defects with twin boundaries in Au: A molecular dynamics study

The molecular dynamics simulation technique with many-body and semi-empirical potentials (based on the embedded atom method potentials) has been used to calculate the interactions of point defects with (1 1 1), (1 1 3), and (1 2 0) twin boundaries in Au at different temperatures. The interactions of single-, di-, and tri-vacancies (at on- and off-mirror sites) with the twin interfaces at 300 K are calculated. All vacancy clusters are favorable at the on-mirror arrangement near the (1 1 3) twin boundary. Single- and di-vacancies are more favorable at the on-mirror sites near the (1 1 1) twin boundary, while they are favorable at the off-mirror sites near the (1 2 0) twin boundary. Almost all vacancy clusters energetically prefer to lie in planes closest to the interface rather than away from it, except for tri-vacancies near the (1 2 0) interface at the off-mirror site and for 3.3 and 3.4 vacancy clusters at both sites near the (1 1 1) interface, which are favorable away from the interface. The interaction energy is high at high temperatures.