Comparison of isotope effects on thermal conductivity of graphene nanoribbons and carbon nanotubes

By using molecular dynamics simulation, we explore the isotope effect on thermal conductivity of graphene nanoribbons (GNRs) and carbon nanotubes (CNTs). For both GNRs and CNTs, the lattice thermal conductivity decreases when isotope concentration increases from 0% to 30%. The thermal conductivity reduction ratio in GNRs is less than that in CNTs. For example, thermal conductivity of CNT with 5% C-13 concentration is 25% lower than that of pure CNTs; however, the reduction in thermal conductivity of GNRs with the same isotope concentration is only about 12%. Lattice dynamics analysis reveals that these phenomena are related to the phonon localization. (C) 2013 AIP Publishing LLC.