Simulation of isotope effects in single crystal sputtering

Sputlering of isoopic (001), (011), and (111) Mo single crystals with 0.15-10 keV Arions at low fluences has been studied by means of computer simulation. Attention was given to the dependence of the preferential emission of light isotopes on ion energy and direction of incidence. It has been shown that the enrichment in light isotopes results mainly from a high contribution to sputtering of recoils of low generations which, in turn, correlates very closely with the crystal transparency and accompanying channeling effects. At glancing incidence, the preferential emission of light isotopes is strongly affected by the surface channeling of bombarding particles.