STOPPING OF 5-100KEV HELIUM IN MOLYBDENUM, CHROMIUM, COPPER AND NICKEL

The stopping power of Mo, Cr, Cu and Ni for He ions at velocities belo w the Bohr velocity has been studied. The stopping power values were d educed by comparing ranges of 5-100 keV He+-ions determined with the e lastic-recoil-detection-analysis (ERDA) method with those obtained in molecular dynamics simulations. The nuclear slowing down was treated t hrough the use of molecular dynamics calculations and a potential obta ined from density-functional theory calculations. The comparisons of t he range profiles showed that the electronic stopping powers given by J.F. Ziegler, J.P. Biersack and U. Littmark (The Stopping Powers and R anges of Ions in Matter, vol, 1, Pergamon press, New York, 1985) had t o be multiplied with a factor of 1.20 +/- 0.07 for Mo and Cr and 1.00 +/- 0.06 for Cu and Ni. (C) 1998 Elsevier Science B.V. All rights rese rved.