Surface effects during ion beam processing of materials

Microstructural changes of surfaces during ion implantation have been investigated on the atomic level by molecular dynamics computer simulations. Unlike past surface studies, which have been focused on the problem of sputtering, the current work examines the effects of collective materials response on surface topography. Collective behavior has been noted for the crystal interior in the context of thermal spikes, but we show here that it can lead to far more dramatic consequences at the surface. The investigation includes implantation in several metals, but emphasizing Pt, Si and Ge. In addition, the study includes the first simulations of implantations of a metallic glass, CuTi, and amorphous Si.