Modification of nanostructures by high-energy ion beams

This paper highlights three recently reported examples in which nanostructures in silica have been modified by bombardment with high energy heavy ions. The first example concerns the transformation of spherical nanocolloids into ellipsoids with the aim to built a photonic crystal by irradiation with 4 MeV xenon ions. The second example refers to writing of micro-structures using an 18 MeV silicon micro-beam and the resulting limitations in structurability. The last example deals with the deformation of metallic cobalt nanoparticles in silica by 200 MeV iodine bombardment. Various deformation mechanisms are briefly examined. The experiments are in favor of melting of the clusters by ion impacts and flow of cobalt into the silica tracks.