Molecular dynamics simulation of low-energy sputtering of Pt (111) surface by oblique Ni atom bombardment

The low-energy sputtering on Pt (111) surface by Ni atom at incident angle in a range of 0 degrees-80 degrees (with respect to the direction normal to the surface) is studied by molecular dynamics simulations. The atomic interaction potential obtained with embedded atom method is used in the simulation. The dependence of sputtering yield, energy and angular distribution of sputtered particles as well as sticking probability of Ni atom on incident angle are discussed. The dependence of sputtering yield on incident angle theta can be divided into three different regions in theta, i.e., theta <= 20 degrees, 20 degrees <= theta <= 60 degrees,and theta >= 60 degrees. Based on sticking probability and movement of incident atom, physical mechanism of low-energy sputtering at oblique particle bombardment is suggested. When the incident angle theta is smaller than 20 degrees, the reflection of incident atom by target atom dominates the sputtering process of surface atom, which is similar to the sputtering mechanism for the case of theta = 0 degrees. While for 20 degrees <= theta <= 60 degrees, the reflection of incident atom is no longer important for the low-energy sputtering. For the case of theta >= 60 degrees, there occurs no sputtering.