arXiv subjects

Mehmet Ertas

Publications and source records attributed to Mehmet Ertas.

5 recordsLinked to original sources

arXiv2014

Blume-Capel model on cylindrical Ising nanowire with core/shell structure: Existence of a dynamic compensation temperatures

We present a study, within a mean-field approach, of the kinetics of the spin-1 Blume-Capel model on cylindrical Ising nanowire in the presence of a time-dependent oscillating external magnetic field. We employ the Glauber transition rates to construct the mean-field dynamical equations. We investigate the thermal behavior of the dynamic order parameters. From these studies, we obtain the dynamic phase transition (DPT) points. Then, we study the temperature dependence of the dynamic total magnetization to find the dynamic compensation points as well as to determine the type of behavior. We also investigate the effect of a crystal-field interaction and the exchange couplings between the nearest-neighbor pairs of spins on the compensation phenomenon and construct the phase diagrams in four different planes. The dynamic phase diagrams contain paramagnetic (P), ferromagnetic (F), the antiferromagnetic (AF), and two coexistence or mixed phase regions, namely, the F + P and AF + P that strongly depend on interaction parameters. The system also exhibits the compensation temperatures, or the N-, P-, Q-, S- type behaviors. Furthermore, we also observed two compensation temperatures, namely W-type behaviors, which this result is compared with some experimental works and a good overall agreement is found.

cond-mat.stat-mech↗

arXiv2014

Magnetic properties of spin-3/2 hexagonal Ising nanowire

Magnetic properties, such as magnetizations, internal energy, specific heat, entropy, Helmholtz free energy and phase diagrams of the spin-3/2 Blume-Capel model on hexagonal Ising nanowire (HIN) with core-shell structure are studied by utilizing the effective-field theory (EFT) with correlations. Moreover, the hysteresis behaviors of the system are also investigated and the effects of Hamiltonian parameters on hysteresis behaviors are discussed, in detail. Finally, the obtained results are compared with some experimental and theoretical results and a qualitatively good agreement is found.

cond-mat.stat-mech↗

arXiv2014

Cylindrical Ising Nanowire in an Oscillating Magnetic Field and Dynamic Compensation Temperature

The magnetic properties of a nonequilibrium spin-1/2 cylindrical Ising nanowire system with core/shell in an oscillating magnetic field are studied by using a mean-field approach based on the Glauber-type stochastic dynamics (DMFT). We employ the Glaubertype stochastic dynamics to construct set of the coupled mean-field dynamic equations. First, we study the temperature dependence of the dynamic order parameters to characterize the nature of the phase transitions and to obtain the dynamic phase transition points. Then, we investigate the temperature dependence of the total magnetization to find the dynamic compensation points as well as to determine the type of behavior. The phase diagrams in which contain the paramagnetic, ferromagnetic, antiferromagnetic, nonmagnetic, surface fundamental phases and tree mixed phases as well as reentrant behavior are presented in the reduced magnetic field amplitude and reduced temperature plane. According to values of Hamiltonian parameters, the compensation temperatures, or the N-, Q-, P-, R-, S-type behaviors in the Neel classification nomenclature exist in the system.

cond-mat.stat-mech↗

arXiv2013

Dynamic behaviors of the hexagonal Ising nanowire

By utilizing the effective-field theory based on the Glauber-type stochastic dynamics, the dynamic behaviors of the hexagonal Ising nanowire (HIN) system in the presence of a time dependent magnetic field are obtained. The time variations of average order parameters and the thermal behavior of the dynamic order parameters are studied to analyze the nature of transitions and to obtain the dynamic phase transition points. The dynamic phase diagrams are introduced in the plane of the reduced temperature versus magnetic field amplitude. The dynamic phase diagrams exhibit coexistence phase region, several ordered phases and critical point as well as a reentrant behavior.

cond-mat.mes-hall↗

arXiv2013

Dynamic phase diagrams of the Blume-Capel model in an oscillating field by the path probability method

We calculate the dynamic phase transition (DPT) temperatures and present the dynamic phase diagrams in the Blume-Capel model under the presence of a time-dependent oscillating external magnetic field by using the path probability method. We study the time variation of the average order parameters to obtain the phases in the system and the paramagnetic (P), ferromagnetic (F) and the F + P mixed phases are found. We also investigate the thermal behavior of the dynamic order parameters to analyze the nature (continuous and discontinuous) of transitions and to obtain the DPT points. We present the dynamic phase diagrams in three planes, namely (T, h), (d, T) and (k2/k1, T), where T is the reduced temperature, h the reduced magnetic field amplitude, d the reduced crystal-field interaction and the k2, k1 rate constants. The phase diagrams exhibit dynamic tricritical and reentrant behaviors as well as a double critical end point and triple point, strongly depending on the values of the interaction parameters and the rate constants. We compare and discuss the dynamic phase diagrams with dynamic phase diagrams that are obtained within the Glauber-type stochastic dynamics based on the mean-field theory and the effective field theory.

cond-mat.stat-mech↗