| Our research has been focused on the identification of possible methods to manipulate nano-structured materials with atomic level precision. We have studied three different types of nano-structured materials; carbon nanotubes, diamond nano-crystallites, and quantum dots on Si surfaces, based on molecular dynamics and first principles pseudopotential method.; For the study of carbon nanotubes, we have developed an analytic model to predict the chemical reactivity of carbon nanotubes. We have shown that the model can predict the chemical reactivity with an accuracy comparable to quantum simulations but without the expensive cost of such simulations. Furthermore, based on the model, we have shown that the controlled functionalization of carbon nanotubes can be achieved through the mechanical deformation of carbon nanotubes.; We have studied the formation of diamond nano-crystallites as an example of the fabrication of nano particles. It was reported that the diamond nanocrystallites can be fabricated out of non-diamond materials, such as compressed bucky onions. Thus, we have investigated the motion of point defects in compressed diamond to understand the fabrication of diamond crystallites. During the study, we have also examined the fabrication of n-type doped diamond crystallite.; Finally, we have investigated the diffusion of adsorbate atoms on Si (111)-(7 × 7) surfaces to understand the formation of the quantum dot on the surface. Quantum dots can form by the diffusion of adsorbate and are destroyed by thermal diffusion. Based on the results, we have proposed that quantum dot fabrication on Si (111)-(7 × 7) surfaces can be controlled by temperature.; We have examined various ranges of manipulation tools from mechanical deformation to operation temperature. Based on our research, we will propose several possible ways to increase the control over nano-structured materials. |
