The epitaxial growth of ultra-thin films on crystalline substrates and the fabrication of nanostructures with atomic resolution will provide exciting, qualitatively new research opportunities. In fact, this growth method would allow the production of systems that can not be obtained through conventional chemical processes.The main goal of this research project is that of exploring new pathways for the fabrication of complex structures with novel physical properties, which could have a great significance from the point of view of technological innovations. For instance, we would like to investigate whether a new class of magnetic systems can be obtained by introducing dilute specific point defects in the crystal structure of conventional materials, which could play an important role in particular in the new field of spintronics [1].
For example, half-metallic ferromagnets could be obtained from simple nonmagnetic band insulators such as CaO [2], and half-metallic antiferromagnets from antiferromagnetic insulators such as NiO [3], which would all be ideal materials for innovative spin-dependent electronics. In addition, one-dimensional nanostructures will be also investigated with respect to the possibility of creating nanowires that exhibit new interesting physical phenomena. These nanostructures could be created on stepped surfaces [4,5], as well as on substrates or films, with the help of molecular beam epitaxy methods and/or atomic manipulation techniques using an STM apparatus [6,7]. At last, it is worth emphasizing that the epitaxial growth of thin films on crystalline substrates will also be applied as a new approach to study the metal-insulator transition in correlated metal such as CaVO3 [8]. By opportunely choosing the film-substrate lattice mismatch, we can attempt to actively tune fundamental parameters such as chemical bond angles and bond lengths (and in turn the overlap integrals between the valence electrons), and this way drive the system through the metal-insulator transition.