Over the last many year, ion beam implantation/irradiation has played an important role in fundamental studies and in development of new technologies as well. The present book includes the work exploring the use of ion beams in nanotechnology. Ion beam irradiation has become an unique tool for fabricating and engineering the nanostructures not only at the surface but also embedded in the matrix. This work includes the use of ion beams ranging from low energy (keV) to high energy (MeV)to fabricate and engineering the properties of metal nanopartices embedded in polymer matrix. This book, thus, provides the basic understanding of ion beam interaction with materials, chemical and physical modifications of materials, synthesis of nanopartices and tailoring of their properties in thin films.