Radiation effects in insulators: past, present, future

Abstract

Interest in the structure and chemical and physical properties of irradiated ionic crystals in the 1960s and 1970s lead to the initiation of this series of conferences with REI-1 at Arco, Lago di Garda (Italy) in 1981. The early programs focused on treatment of collisional events in insulators (mainly from ions) and the physical and chemical properties of defects. Studies were about evenly distributed among halides, oxides, glasses and organic polymers. Radiation effects in nuclear waste materials and “hot” chemistry were important subjects during the mid to late 1980s but interest in these areas has decreased. In recent years, the addition of laser-induced effects has grown and the interest in polymers has focused on tailoring surfaces for specific applications, e.g. biomedical. Researches on covalent-bonded materials (SiC and diamond), complex oxides (spinels, etc.) and nanoclusters have become more prevalent. Theoretical and modeling treatments have moved from treatment of single collision events to molecular dynamics modeling of events associated with cascades. Many fundamental questions remain that will be studied by increasingly improved experimental techniques and modeling. The modeling studies will progress from describing events that occur during the first few picoseconds to description of microstructural developments. There should be renewed interest in secondary effects such as the influence of electronic excitation on defect diffusion and stability. The future of ion beam produced nanoclusters rests upon a demonstration of its ability to satisfy the demands of some unique application.