Defect Induced Variabilities in Thermal Conductivity of Nano Structures

The high thermal conductivity of carbon nanotubes makes them ideal candidates for use as nano-fins for thermal management in electronics and composites. At the nanoscale, the thermal conductivity of nanotubes are found to be dependent on size, strain states, temperature, and presence of defects and vacancy. The proper understanding of the effect of these parameters are important in constructing a nanotube system with desired thermal characteristics. Here, we pay special focus on the effect of different kinds of defects and vacancies on the thermal conductivities of nanotubes. Defects and vacancies are imperfections in an otherwise hexagonal structure of nanotube. Their presence have shown to impede the thermal transport in nano-structures which is attributed to the scattering of phonons that occurs in these imperfections. The thermal conductivities of (10,10) armchair nanotube with defects and vacancies are determined using the heat bath method, a non-equilibrium molecular dynamic simulation and are compared with that of pristine carbon nano-structures. This is followed by the comparative study of phonon density of states of nanotubes with and without the defects.