Ion irradiation effects in nonmetals: formation of nanocrystals and novel microstructures

Ion implantation is a versatile and powerful technique for producing nanocr ystal precipitates embedded in the near-surface region of materials. Radiat ion effects that occur during the implantation process can lead to complex microstructures and particle size distributions, and in the present work, w e focus on the application of these effects to produce novel microstructura l properties for insulating or semiconducting nanocrystals formed in optica l host materials. Nanocrystal precipitates can be produced in two ways: by irradiation of pure (i.e., non-implanted) crystalline or amorphous material s, or by ion implantation followed by either thermal annealing or subsequen t additional irradiation. Different methods for the formation of novel stru ctural relationships between embedded nanocrystals and their hosts have bee n developed, and the results presented here demonstrate the general flexibi lity of ion implantation and irradiation techniques for producing unique ne ar-surface nanocomposite microstructures in irradiated host materials.