Yazar "Bayri, A." seçeneğine göre listele

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    Alternating Heisenberg s=1/2 spin chain
    (Natl Inst Optoelectronics, 2006) Isik, F.; Ekmekci, S.; Bayri, A.
    Spin ladder systems containing CuCl3 and CuBr3 show very interesting magnetic behaviour, which are alternate Heisenberg chains with ferromagnetic and antiferromagnetic interactions. Since these systems contain triangles of magnetic centers, we developed a model based on non-interacting triangular units, which may be used for interpretation of magnetic measurements of these systems in some extreme limits. We took the Heisenberg model type interactions for magnetic center and used different types of exchange coupling between the neighbours. The results obtained from our approximations may be used in order to interpret the experimental magnetic measurements in KCuCl3 and TiCuCl3 complexes and for the singlet-triplet transition temperature.
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    Determination of Exchange Coupling of Dimethoxo-Bridged Dichromium(III) Complexes and Magnetic Field Dependence of Magnetization
    (Springer, 2013) Isik, F.; Sabaner, M. A.; Akan, A. T.; Bayri, A.
    The density functional theory method is used to calculate the exchange coupling constant in dimethoxo-bridged dichromium(III) complex. It is found that the bridge angle has an important role for the coupling constant. It is realized that the coupling constant changes its sign by variation of the bridge angle. From the calculation it is clear that there is a phase transition from ferromagnetism to antiferromagnetism at a certain bridge angle.
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    Investigation of Spin State Transition of [FeC17H31N7]2+ Compound by Using the Density Functional Method
    (Springer, 2017) Isik, F.; Sabaner, M. A.; Erboz, Duygu; Sahinbas, Taylan; Bayri, A.
    The symmetry of the [FeC17H31N7](2+) novel compound is close to octahedral which has spin crossover properties (SCO). In this study, geometrical optimization, IR vibration frequencies, and HOMO-LUMO energy differences at various temperatures of the compound were calculated by DFT. It is realised that the computed splitting energies and splitting free enthalpies together with the mole fraction of HS state are compatible with the experiment.
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    Theoretical approach to the magnetic properties of Co(II) ion in CoL2•5H2O compound (L is 5-chloro-2-methoxybenzoate)
    (Springer, 2006) Bayri, A.; Sulu, M.; Isik, F.
    The magnetic moments of a Co(II) complex in a recently reported CoL(2)(.)5H(2)O compound (L is 5-chloro-2-methoxybenzoate, ClC6H3(OCH3)COO-) were studied by a semi-theoretical approach in the vicinity of tetragonal distortion. It was found that in order to obtain the observed temperature-dependent magnetic moments, some parameters in the magnetic Hamiltonian which are related to the geometry of the complex should be varied. Comparing the calculated results of this study with experimental results from the literature, a distorted octahedral environment of Co(II) ion in the compound is predicted. Also, rather high probability of large orbital contribution to the magnetic moment is expected. Some abnormalities in previously reported data might be reduced by taking the experimental data with VSM (Vibrational Susceptibility Magnetometer).
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    Theoretical investigation of ferromagnetic-antiferromagnetic transition in a dinuclear Cu(II) complex with a structural deformation of core
    (Indian Assoc Cultivation Science, 2013) Isik, F.; Sabaner, M. A.; Akan, A. T.; Bayri, A.
    The magnetic properties of the dinuclear Cu(II) complex (especially for dichloro(guaninium)copper(II)) is investigated by broken-symmetry density functional method. Some of unrestricted DFT calculations with the 6-311G(d,p) basis sets for the lighter atoms indicate that the copper atoms may interact with either ferromagnetically or antiferromagnetically depending on the bridging angle of the ligand. The numerical calculations indicate a ferromagnetic coupling occurs below 92A degrees while the antiferromagnetic interactions start to emerge when the angle is greater than this value for this particular dinuclear complex.
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    Theoretical Magnetic Behavior of NbO-type Cu2 MOF
    (Springer, 2015) Sabaner, M. A.; Isik, F.; Sahinbas, T.; Bayri, A.
    This study reports the temperature dependences of magnetic properties of NbO-type Cu-2 metal organic frameworks (MOF). Using the isotropic Heisenberg Hamiltonian and the coupling constant, which is taken in the literature, it is found that the Neel temperature of these complexes is too low. It is suggested that the Neel temperature may be increased by some geometrical distortion.