Now showing items 1-20 of 23

    • Armchair nanoribbons of silicon and germanium honeycomb structures 

      Cahangirov, S.; Topsakal, M.; Çıracı, Salim (American Physical Society, 2010)
      We present a first-principles study of bare and hydrogen passivated armchair nanoribbons of the puckered single layer honeycomb structures of silicon and germanium. Our study includes optimization of atomic structure, ...
    • A comparative study of lattice dynamics of three-and two-dimensional MoS2 

      Ataca, C.; Topsakal, M.; Aktürk, E.; Çıracı, Salim (American Chemical Society, 2011)
      This paper presents a comparative study of the lattice dynamics of three-dimensional layered MoS2 and two-dimensional single layer MoS2 based on the density functional theory. A comprehensive analysis of energetics and ...
    • Current-voltage (I-V) characteristics of armchair graphene nanoribbons under uniaxial strain 

      Topsakal, M.; Bagci, V.M.K.; Çıracı, Salim (American Physical Society, 2010)
      The current-voltage characteristics of armchair graphene nanoribbons under a local uniaxial tension are investigated by using first-principles quantum transport calculations. It is shown that for a given value of bias ...
    • Domain formation on oxidized graphene 

      Topsakal, M.; Çıracı, Salim (American Physical Society, 2012-11-01)
      Abstract Using first-principles calculations within density functional theory, we demonstrate that the adsorption of a single oxygen atom results in significant electron transfer from graphene to oxygen. This strongly ...
    • Effects of charging and electric field on graphene oxide 

      Topsakal, M.; Gürel, H. H.; Çıracı, Salim (American Chemical Society, 2013)
      We present a first-principles study of various effects of charging and electric field on the oxidation/deoxidation of graphene oxide consisting of only epoxy groups. We first determined the proper basis set, which hinders ...
    • Effects of static charging and exfoliation of layered crystals 

      Topsakal, M.; Çıracı, Salim (American Physical Society, 2012)
      Using a first-principle plane-wave method we investigate the effects of static charging on the structural, electronic, and magnetic properties of suspended, single-layer graphene, graphane, fluorographene, BN, and MoS 2 ...
    • Elastic and plastic deformation of graphene, silicene, and boron nitride honeycomb nanoribbons under uniaxial tension: A first-principles density-functional theory study 

      Topsakal, M.; Çıracı, Salim (American Physical Society, 2010)
      This study of elastic and plastic deformation of graphene, silicene, and boron nitride BN honeycomb nanoribbons under uniaxial tension determines their elastic constants and reveals interesting features. In the course of ...
    • Electronic and magnetic properties of 3d transition-metal atom adsorbed graphene and graphene nanoribbons 

      Sevinçli, H.; Topsakal, M.; Durgun, Engin; Çıracı, Salim (American Physical Society, 2008)
      In this paper, we theoretically studied the electronic and magnetic properties of graphene and graphene nanoribbons functionalized by 3d transition-metal (TM) atoms. The binding energies and electronic and magnetic properties ...
    • First-principles approach to monitoring the band gap and magnetic state of a graphene nanoribbon via its vacancies 

      Topsakal, M.; Aktürk, E.; Sevinçli, H.; Çıracı, Salim (American Physical Society, 2008)
      Using first-principles plane-wave calculations we predict that electronic and magnetic properties of graphene nanoribbons can be modified by the defect-induced itinerant states. Structure optimization gives rise to significant ...
    • First-principles study of defects and adatoms in silicon carbide honeycomb structures 

      Bekaroglu, E.; Topsakal, M.; Cahangirov, S.; Çıracı, Salim (The American Physical Society, 2010)
      We present a study of mechanical, electronic and magnetic properties of two-dimensional (2D), monolayer of silicon carbide (SiC) in honeycomb structure and its quasi-one-dimensional (quasi-1D) armchair nanoribbons using ...
    • First-principles study of two-and one-dimensional honeycomb structures of boron nitride 

      Topsakal, M.; Aktürk, E.; Çıracı, Salim (American Physical Society, 2009)
      This paper presents a systematic study of two- and one-dimensional honeycomb structures of boron nitride BN using first-principles plane-wave method. In order to reveal dimensionality effects, a brief study of all allotropic ...
    • First-principles study of zinc oxide honeycomb structures 

      Topsakal, M.; Cahangirov, S.; Bekaroglu, E.; Çıracı, Salim (American Physical Society, 2009)
      We present a first-principles study of the atomic, electronic, and magnetic properties of two-dimensional 2D, single and bilayer ZnO in honeycomb structure and its armchair and zigzag nanoribbons. In order to reveal the ...
    • Frictional figures of merit for single layered nanostructures 

      Cahangirov, S.; Ataca, C.; Topsakal, M.; Sahin, H.; Çıracı, Salim (American Physical Society, 2012)
      We determine the frictional figures of merit for a pair of layered honeycomb nanostructures, such as graphane, fluorographene, MoS 2 and WO 2 moving over each other, by carrying out ab initio calculations of interlayer ...
    • Functionalization of graphene nanoribbons 

      Sevinçli H.; Topsakal, M.; Çıracı, Salim (2013)
      With the synthesis of a single atomic plane of graphite, namely, graphene honeycomb structure, a new perspective for carbon-based electronics is opened. The one-dimensional graphene nanoribbons (GNRs) have different band-gap ...
    • Graphene coatings: an efficient protection from oxidation 

      Topsakal, M.; Şahin, H.; Çıracı, Salim (American Physical Society, 2012)
      We demonstrate that graphene coating can provide efficient protection from oxidation by posing a high-energy barrier to the path of oxygen atom, which could have penetrated from the top of the graphene to the reactive ...
    • Long-range interactions in carbon atomic chains 

      Cahangirov, S.; Topsakal, M.; Çıracı, Salim (American Physical Society, 2010)
      Based on first-principles calculations we revealed fundamental properties of infinite and finite-size monatomic chains of carbon atoms in equilibrium and under an applied strain. Distributions of bond lengths and magnetic ...
    • Monolayer honeycomb structures of group-IV elements and III-V binary compounds: First-principles calculations 

      Şahin, H.; Cahangirov, S.; Topsakal, M.; Bekaroglu, E.; Akturk, E.; Senger, R. T.; Çıracı, Salim (American Physical Society, 2009)
      Using first-principles plane-wave calculations, we investigate two-dimensional (2D) honeycomb structure of group-IV elements and their binary compounds as well as the compounds of group III-V elements. Based on structure ...
    • The response of mechanical and electronic properties of graphane to the elastic strain 

      Topsakal, M.; Cahangirov, S.; Çıracı, Salim (AIP Publishing LLC, 2010)
      Based on first-principles calculations, we resent a method to reveal the elastic properties of recently synthesized monolayer hydrocarbon, graphane. The in-plane stiffness and Poisson’s ratio values are found to be smaller ...
    • Spin confinement in the superlattices of graphene ribbons 

      Topsakal, M.; Sevinçli, H.; Çıracı, Salim (AIP Publishing, 2008)
      Based on first-principles calculations, we showed that repeated heterostructures of zigzag graphene nanoribbons of different widths form multiple quantum well structures. Edge states of specific spin directions can be ...
    • Static charging of graphene and graphite slabs 

      Topsakal, M.; Çıracı, Salim (Nature Publishing Group, 2011)
      The effect of external static charging of graphene and its flakes are investigated by using first-principles calculations. While the Fermi level of negatively charged graphene rises and then is quickly pinned by the ...