High-resolution TEM study of ion beam irradiation induced amorphization in ceramic materials

Radiation damage of nuclear materials (e.g. fast- or fusion-neutron damage in reactor structural components, fission-fragment damage in nuclear fuels and alpha decay damage in nuclear waste forms) has been one of the major challenges faced by the material science community. Ion beam irradiation and implantation experiments have been used extensively in the past few decades not only for simulating these damaging process in materials but also for improving material properties for many technological applications.As an energetic particle traverses a crystalline target, it loses its energy predominantly through electronic (ionization) and nuclear (elastic collision) interactions with the atoms in the lattice. The target atom which receives sufficient energy from the interactions may get displaced from its lattice site and may further displace other target atoms, thus creating a displacement cascade which is usually a few nanometers in scale. Just at the end of the collision phase, which lasts for only a few tenths of a picosecond, a displacement cascade contains a very dense cluster of point defects and the region may be considered amorphous.