Effect of interatomic potential on the sputtering of Pd surfaces

Abstract

Ion sputtering of surfaces is a widely used technique, for instance utilized to modify surfaces or surface features. Another commonly used technique is the utilization of sputtering to coat another material, where sputtering targets are used to release atoms in order to redeposit them. In self-ion molecular dynamics sputtering simulations, the interatomic potential between the ion and the matrix material is usually the same as for the matrix material. However, for sputtering by ions of different type, the choice is not as self-evident. For most elements, a well-fitted many-body interatomic potential is not available in the literature, and simple pair potentials are used. Quite commonly, the potential between the ion and the matrix is used with no further validation. In this article, we investigate the effect of choice of interatomic potential on the sputtering yield of the sample material palladium by argon ions. We utilize three commonly used pair potential forms, as well as modify these to obtain in total 11 different interatomic potentials for the Ar-Pd interaction. We found that the choice of interatomic potential can drastically affect the low energy sputtering of the surfaces. Additionally, four different surface orientations were simulated to see possible differences. To investigate continuous irradiation, in order to obtain the evolution of surface during prolonged irradiation, cumulative sputtering simulations were carried out.