R.S. Averback

Department of Materials Science and Engineering

University of Illinois at Urbana-Champaign

Bombardment of surfaces with energetic ions is a critical element in many surface analysis methods. The purpose of the ion beam is generally to erode the surface for either cleaning or for probing the material below by surface methods. Ion beams do far more than simply eroding the surface, however, they alter the roughness of the surface, the local stress, and the surface composition. In this presentation the results of molecular dynamics simulations and key experimental results will be highlighted to illustrate the basic mechanisms controlling these changes in the morphology of bombarded surfaces. The experiments will focus on recent results of surface smoothing and stress relaxation in both metallic glasses and nanocrystalline composites, although some results on polycrystalline and single crystalline materials will also be presented for comparison.