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Aycan Özkan

Publications and source records attributed to Aycan Özkan.

4 recordsLinked to original sources

Critical Behavior of Low Dimensional Magnetic Systems

In this study, critical behavior of low dimensional magnetic systems as cyano-bridged Tb(III)-Cr(III) bimetallic assembly was investigated with the mixed spin $3$- spin $3/2$ Ising model. The mixed spin Ising model is simulated with Cellular Automaton cooling and heating algorithms on one-dimensional lattices in periodic boundary conditions. The Ising model Hamiltonian includes only antiferromagnetic nearest-neighbor interaction ($% J>0$). The mixed spin system behaves like the isolated one-dimensional chain for zero magnetic field ($h=\frac{H}{J}=0$). In the presence of the magnetic field, the magnetization is calculated using zero-field cooling ($ZFC$) and field cooling ($FC$) processes. The one-dimensional Ising model results are compatible with the cyano-bridged Tb(III)-Cr(III) bimetallic quasi-one dimensional assembly [Tb(H_{2}O)_{2}(DMF)_{4}{ Cr(CN)_{6}}].H_{2}O(DMF=dimethylformamide) results.

physics.comp-ph↗

The effect of the heating rate on the order to order phase transition

The simple cubic spin-1 Ising (BEG) model exhibits the ferromagnetic (F) - ferromagnetic (F) phase transition at low temperature region for the interval 1.40<d=D/J<1.48 at k=K/J=-0.5. The degree of the F-F phase transtion determines the special point on the (kT/J, d) phase diagram In this paper, the critical behavior of the ferromagnetic (F) - ferromagnetic (F) phase transition has been investigated for different heating rates using the cellular automaton (CA) heating algorithm. The variations with heating rate for the F-F phase transition order are quite important at the creation of phase diagrams. Therefore, the universality class and the type of ferromagnetic (F) - ferromagnetic (F) phase transition have been researched using the finite - size scaling theory, the power law relations and the probability distributions. The results show that the F-F phase transition can be the second order, the first order or the weak first order depending on the heating rate in the interval 1.40<d<1.48 for k=-0.5.

cond-mat.stat-mech↗

The Mixed Spin 3 - Spin 3/2 Ferrimagnetic Ising Model on Cellular Automaton

The mixed spin 3- spin 3/2 Ising model has been simulated using cooling algorithm on cellular automaton (CA). The simulations have been made in the interval -6<=D<=6 for J=1 for the square lattices with periodic boundary conditions. The ground state phase diagram of the model has different type ferrimagnetic orderings. Through D/J=2 line, compensation points occurs at kT/J=0. The values of the critical exponents ( ν, α, β and γ) are estimated within the framework of the finite-size scaling theory and power law relations for selected D/J values (-2, 0, 1, 2 and 4). The estimated critical exponent values are in a good agreement with their universal values of the two dimensional Ising model.

cond-mat.stat-mech↗

Finite-Size Scaling and Power Law Relations for Dipol-Quadrupol Interaction on Blume-Emery-Griffiths Model

The Blume-Emery-Griffiths model with the dipol-quadrupol interaction (\ell) has been simulated using a cellular automaton algorithm improved from the Creutz cellular automaton (CCA) on the face centered cubic (fcc) lattice. The finite-size scaling relations and the power laws of the order parameter (M) and the susceptibility (χ) are proposed for the dipol-quadrupol interaction (\ell). The dipol-quadrupol critical exponent δ_{\ell} has been estimated from the data of the order parameter (M) and the susceptibility (χ). The simulations have been done in the interval 0\leq \ell =L/J\leq 0.01 for d=D/J=0, k=K/J=0 and h=H/J=0 parameter values on a face centered cubic (fcc) lattice with periodic boundary conditions. The results indicates that the effect of the \ell parameter is similar to the external magnetic field (h). The critical exponent δ_{\ell}$ are in good agreement with the universal value (δ_{h}=5) of the external magnetic field.

cond-mat.stat-mech↗