Now showing items 1-20 of 223

    • Ab initio temperature dependent studies of the homoepitaxial growth on Si(0 0 1) surface 

      Dağ, S.; Çıracı, Salim; Kılıç, Ç.; Fong, C. Y. (2001)
      We performed ab initio zero temperature and finite temperature molecular dynamics calculations to investigate the homoepitaxial growth on the Si(0 0 1) surface. How do the deposited atoms (adatoms) form addimers and how ...
    • Ab-initio atomic scale study of nearly frictionless surfaces 

      Çıracı, Salim; Yıldırım, T.; Dağ, S.; Gülseren, Oğuz (Elsevier, 2007)
      This chapter presents a comparative analysis of the dry sliding friction between the atomically flat and commensurate surfaces of two different systems: between two diamond (001) surfaces and between two BN (001) surfaces. ...
    • Ab-initio electron transport calculations of carbon based string structures 

      Tongay, S.; Senger, R. T.; Dag, S.; Çıracı, Salim (American Physical Society, 2004)
      The new stable structures of carbon-based strings and their unusual electronic transport properties were discussed. Total energy and electronic structure calculations using first principles pseudopotential plane wave method ...
    • Above room temperature ferromagnetism in Gd2B2 monolayer with high magnetic anisotropy 

      Görkan, T.; Vatansever, E.; Akıncı, Ü.; Gökoğlu, G.; Aktürk, E.; Çıracı, Salim (American Chemical Society, 2020)
      The realization of 2D ultrathin crystals with a ferromagnetic ground state that is sustainable at room temperature has been a real challenge now. By combining ab initio density functional theory with Monte Carlo simulations, ...
    • Absence of metallicity in Cs-GaAs(110): A Hubbard-model study 

      Gedik, Z.; Çıracı, Salim; Batra, I. P. (American Physical Society, 1993)
      Using an approximate solution of the Hubbard-model Hamiltonian, we are able to establish that the Cs-GaAs(110) system becomes a Mott insulator at submonolayer Cs coverages. We also provide a consistent interpretation of ...
    • Adhesive energy, force and barrier height between simple metal surfaces 

      Çıracı, Salim; Tekman, E.; Gökçedag, M.; Batra, I. P.; Baratoff, A. (1992)
      Using the self-consistent field pseudopotential method we calculated the adhesive energy, perpendicular and lateral forces and barrier height between two rigid A1(001) slabs modeling the sample and a blunt tip. We found ...
    • Adsorption and dissociation of hydrogen molecules on bare and functionalized carbon nanotubes 

      Dag, S.; Ozturk, Y.; Çıracı, Salim; Yildirim, T. (American Physical Society, 2005)
      Interaction between hydrogen molecules and bare as well as functionalized single-wall carbon nanotubes (SWNT) is investigated using first-principles plane wave method. It is found that the binding energy of the H2 physisorbed ...
    • Adsorption of carbon adatoms to graphene and its nanoribbons 

      Ataca, C.; Aktürk, E.; Şahin, H.; Çıracı, Salim (AIP Publishing, 2011)
      This paper investigates the adsorption of carbon adatoms on graphene and its nanoribbons using first-principles plane wave calculations within density functional theory. The stability at high carbon adatom coverage, ...
    • Adsorption of group IV elements on graphene, silicene, germanene and stanene: dumbbell formation 

      Ozcelik, V. O.; Kecik, D.; Durgun, Engin; Çıracı, Salim (ACS Publications, 2014-12-09)
      Silicene and germanene derivatives constructed from periodic dumbbell units play a crucial role in multilayers of these honeycomb structures. Using first-principles calculations based on density functional theory, here ...
    • Adsorption site of alkali metal overlayers on Si(001) 2 × 1 

      Batra, I. P.; Çıracı, Salim (1992)
      The alkali metal semiconductor interfaces are currently being investigated by a variety of tools. Most studies to date at half a monolayer coverage have shown preference for either a quasi-hexagonal (H) site or a long-bridge ...
    • 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, ...
    • Atomic and electronic structure of carbon strings 

      Tongay, S.; Dag, S.; Durgun, Engin; Senger, R. T.; Çıracı, Salim (IOP Publishing Ltd., 2005)
      This paper presents an extensive study of various string and tubular structures formed by carbon atomic chains. Our study is based on first-principles pseudopotential plane wave and finite-temperature ab initio molecular ...
    • Atomic and electronic structures of doped silicon nanowires: A first-principles study 

      Durgun, Engin; Akman, N.; Ataca, C.; Çıracı, Salim (2007)
      We have investigated the atomic and electronic structures of hydrogen saturated silicon nanowires doped with impurity atoms (such as Al, Ga, C, Si, Ge, N, P, As, Te, Pt) using a first-principles plane wave method. We ...
    • Atomic chains of group-IV elements and III-V and II-VI binary compounds studied by a first-principles pseudopotential method 

      Senger, R. T.; Tongay, S.; Durgun, Engin; Çıracı, Salim (American Physical Society, 2005)
      Using the first-principles plane wave pseudopotential method we have studied structural, electronic, and transport properties of atomic chains of group-IV elements and group III-V and group II-VI binary compounds. Several ...
    • Atomic scale study of friction and energy dissipation 

      Çıracı, Salim; Buldum, A. (Elsevier, 2003-05)
      This paper presents an analysis of the interaction energy and various forces between two surfaces, and the microscopic study of friction. Atomic-scale simulations of dry sliding friction and boundary lubrication are based ...
    • Atomic scale study of superlow friction between hydrogenated diamond surfaces 

      Dag, S.; Çıracı, Salim (American Physical Society, 2004)
      Strong attractive interaction between two clean diamond (001) slabs turns repulsive upon the hydrogenation of surfaces. This repulsive interaction serves as if a boundary lubricant and prevents the sliding surfaces from ...
    • Atomic strings of group IV, III-V, and II-VI elements 

      Tongay, S.; Durgun, Engin; Çıracı, Salim (American Institute of Physics, 2004)
      A systematic first-principles study of atomic strings made by group IV, III-V, and II-VI elements has revealed interesting mechanical, electronic, and transport properties. The double bond structure underlies their unusual ...
    • Atomic structure of the √3 × √3 phase of silicene on Ag (111) 

      Cahangirov, S.; Özçelik, V. O.; Xian, L.; Avila, J.; Cho, S.; Asensio, M. C.; Çıracı, Salim; Rubio, A. (American Physical Society, 2014-07-28)
      The growth of the 3√×3√ reconstructed silicene on Ag substrate has been frequently observed in experiments while its atomic structure and formation mechanism is poorly understood. Here, by first-principles calculations, ...
    • Atomic theory of scanning tunneling microscopy 

      Tekman, E.; Çıracı, Salim (American Physical Society, 1989)
      We present a quantitative analysis of the modifications of the scanning-tunneling-microscopy images due to the local perturbations of the electronic states induced by the tip in close proximity to the sample surface. Using ...
    • Atomic-scale study of dry sliding friction 

      Buldum, A.; Çıracı, Salim (American Physical Society, 1997)
      We present a theoretical study of dry sliding friction, which has a close bearing on the experiments done by using the atomic and friction force microscope. By performing atomic-scale calculations for the friction between ...