Authors: Y. Umeno and T. Kitamura
Affilation: Kyoto University, Japan
Pages: 41 - 44
Keywords: ab initio, deformation, mechanical property, electronic structure, silicon, nickel, carbon nanotube
Nanostructures have been attracting attention because of their prominent properties, and their applications for novel devices with advanced functions have been attemted. Large stress and strain occur in local regions in materials with nanostructures owing to their complex structures. In this study, we conduct ab initio simulations to elucidate the mechanical and electronic properties of materials, which are essential for designing functional nanomaterials. Firstly, we investigate in detail the deformation of crystals, such as silicon and nickel, and the change in their electronic structures under deformation. We nd that the strain largely changes the electronic structures of the crystals, resulting in the changes in the electric conductivity of silicon and the magnetic property of nickel. Secondly, we conduct simulations on the deformation of carbon nanotubes, which are among greatly notable nanomaterials. We nd that the electric conductivity of the carbon nanotubes shows transitions from metallic to semiconducting and vice versa under axial tension. We also nd that the semiconducting nanotubes become metallic under radial compression, while the metallic nanotubes do not show the transition.