Molecular dynamics simulation of the isotopic mass effect in zero-fluence and low-bombarding-energy sputtering

Nonstoichiometric effects in the zero-fluence sputtering of a natural Cu 111.target 69.1% 63Cu, 30.9% 65Cu. irradiated with normally incident Arq ions from 50 to 1000 eV have been studied by use of a molecular dynamics MD.simulation code. Calculations show that the isotopic ratios in the normal direction and at oblique angles, their difference, and the total isotopic ratio increase as the bombarding energy decreases. q1999 Elsevier Science B.V. All rights reserved