|
Initial stages of a crystal surface morphology evolution under local impact of lowenergy
(of the order of eV and even less) particle beam were studied and a simulation of this
process was performed using molecular dynamics. It is shown that change in the crystal
morphology can be caused by a vacancy flow towards the spot of the beam incidence along
crystallographic directions corresponding to phonon propagation. The mathematical model of
this process is proposed and surface profile change rate is estimated. A mechanism of surface
roughness development on initially flat surface under impact of uniform particle flux over the
whole area is discussed, and morphological stability criterion is found. It is shown that in certain
cases one can smooth the surface of the crystal overcoming other mechanisms of spontaneous
roughness development.
Keywords: crystal morphology; surface profile; flow of low-energy particles; vacancy mechanism; molecular dynamics simulation. |
full paper (pdf, 1456 Kb)