Molecular dynamics simulations of Ar+ bombardment of Fe(0,0,1), (1,0,1), and (1,1,1) surfaces: Study of threshold energy and angular characteristics of sputtering

The surface-sputtering or ion bombardment processes of solid materials have attracted considerable attention due to their applications in materials science and technology. Here, using the classical molecular dynamics simulations, we investigate the low-energy sputtering process of iron in the argon plasma by taking into account the primary knock-on atom (PKA) and secondary knock-on atom (SKA) for different crystal plane orientations. Moreover, the effect of projectile energy on the sputtering yields and the influence of the incident angle of Ar+ ions on these yields, the threshold energy, and the surface binding energy is analyzed. It is shown that the maximum sputtering yields due to the PKA and SKA processes are in the range of 5 to 15 degrees and 15 to 25 degrees, respectively. It is also indicated that the lowest binding and threshold energies of iron are related to the incident angle of 37 degrees and Fe(1,1,1) where the atoms have a lot of space to move and collide with other Iron atoms. Finally, we examine the azimuthal and polar angle distributions of the sputtered atoms to obtain the optimal angle in order to the deposition of sputtered atoms.