Structural changes of NaCl and Si single crystal surfaces under ion bombardment

The surface structural changes under ion bombardment of NaCl and Si monocrystalline specimens are followed using electron microscopic technique. Formations and regions with circular symmetry are registered on the surface of NaCl and Si single crystals. Qualitative interpretation of the generation mechanism of the circular formations is made. The ion bombardment is used for the visualization of the surface structure of the specimens by the method of crystal selfdecoration.