On the formation of argon-vacancy clusters in copper irradiated with 4 to 6 kV argon ions

Abstract

A computer simulation study is set up to obtain the energies of stability for argon‐vacancy clusters. The ion‐milling technique utilized in the preparation of copper crystals for transmission electron microscopy (TEM) leads to such a simulation study. The electron images contain a large number of “black dots” and the diffraction patterns show severe streaking in the <111> direction. Several configurations of argon‐vacancy clusters are calculated, namely: spherical as well as planar. Further, the depths are calculated to which energy is deposited by argon bombardment on a copper surface. It is in agreement with experimental observations that the clusters of argon atoms are much more stabilized in the presence of vacancies on {111} than occurs on {110} and on {100} planes and that all the defects are produced in a narrow layer close to the surface.