Yazar "Kadioglu, Y." seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim Yok
    Öğe
    Adsorption of CO and O2 on AumCun clusters: First principles calculations
    (Elsevier Science Sa, 2015) Kadioglu, Y.; Gokoglu, G.; Akturk, O. Uzengi
    The adsorption of CO and O-2 molecules on Au-n (n = 2-5), Cu-n(n= 2-5), and AumCun (m= 1, 2, 3; 1 = n = 6) clusters is investigated in the framework of density functional theory. The equilibrium atomic geometry and electronic structure of each cluster are determined. It is found that Au-n (n= 2-5) clusters show strong reactivity toward CO, while they do not bind to molecular oxygen. High adsorption energy values can be obtained for odd number of Cu-n clusters for both CO and O-2 adsorptions. Cu top site is energetically preferred for the adsorption of both CO and O-2 molecules in AumCun clusters. The results of electronic density of states show an sp hybridization between Cu and O atoms in O-2 adsorbed AumCun clusters. This interaction plays a major role in their binding. The highest occupied molecular orbital and the lowest unoccupied molecular orbital energy gap values and charge density differences are presented. There are charge transfers from s and d orbital electrons of Cu to p orbitals of C and of O atoms. It is observed that O-2 adsorption on some clusters can induce half metallicity which is an ideal property for possible applications in spintronics. (C) 2015 Elsevier B.V. All rights reserved.
  • Küçük Resim Yok
    Öğe
    Mechanical and Electrical Monitoring in the Dynamics of Twisted Phosphorene Nanoflakes on 2D Monolayers
    (Amer Chemical Soc, 2019) Gorkan, T.; Kadioglu, Y.; Akturk, O. Uzengi; Gokoglu, G.; Akturk, E.; Ciraci, S.
    We investigated the rotational and translational dynamics of hydrogen-passivated, black phosphorene and blue phosphorene nanoflakes of diverse size and geometry anchored to graphene, black phosphorene, blue phosphorene, and MoS2 monolayer substrates. The optimized attractive interaction energy between each nanoflake and monolayer substrates are harmonic for small angular displacements, leading to libration frequencies. We showed that the relevant dynamical parameters and resulting libration frequencies, which vary with the size/geometry of nanoflakes, as well as with the type of substrate, can be monitored by charging, external electric field, pressure, and also by a molecule anchored to the flake. The optimized energy profiles and energy barriers thereof have been calculated in translational and in large angle rotational dynamics. Owing to the weak interaction between the flakes and monolayers the energy barriers are particularly small for incommensurate systems and can renders nearly frictionless rotation and translation, which is crucial for nanoscale mechanics. Even if small for particular combined nanoflake + monolayer heterostructures, the energy band gaps exhibit variations with angular and linear displacements of nanoflakes. However, these band gaps undergo considerable reduction under pressure. With tunable dynamics, electronic structure, and low friction coefficients, individual or periodically repeating nanoflakes on a monolayer substrate constitute critical composite structures offering the design of novel detectors, nanomechanical, electromechanical, and electronic devices.