Using the mean-field theory and Glauber-type stochastic dynamics, we study the dynamic magnetic properties of the mixed spin (2, 5/2) Ising system for the antiferromagnetic/antiferromagnetic (AFM/AFM) interactions on the bilayer square lattice under a time varying (sinusoidal) magnetic field. The time dependence of average magnetizations and the thermal variation of the dynamic magnetizations are examined to calculate the dynamic phase diagrams. The dynamic phase diagrams are presented in the reduced temperature and magnetic field amplitude plane and the effects of interlayer coupling interaction on the critical behavior of the system are investigated. We also investigate the influence of the frequency and find that the system displays richer dynamic critical behavior for higher values of frequency than that of the lower values of it. We perform a comparison with the ferromagnetic/ferromagnetic (FM/FM) and AFM/FM interactions in order to see the effects of AFM/AFM interaction and observe that the system displays richer and more interesting dynamic critical behaviors for the AFM/AFM interaction than those for the FM/FM and AFM/FM interactions.
Using the mean-field theory and Glauber-type stochastic dynamics, we study the dynamic magnetic properties of the mixed spin (2, 5/2) Ising system for the antiferromagnetic/antiferromagnetic (AFM/AFM) interactions on the bilayer square lattice under a time varying (sinusoidal) magnetic field. The time dependence of average magnetizations and the thermal variation of the dynamic magnetizations are examined to calculate the dynamic phase diagrams. The dynamic phase diagrams are presented in the reduced temperature and magnetic field amplitude plane and the effects of interlayer coupling interaction on the critical behavior of the system are investigated. We also investigate the influence of the frequency and find that the system displays richer dynamic critical behavior for higher values of frequency than that of the lower values of it. We perform a comparison with the ferromagnetic/ferromagnetic (FM/FM) and AFM/FM interactions in order to see the effects of AFM/AFM interaction and observe that the system displays richer and more interesting dynamic critical behaviors for the AFM/AFM interaction than those for the FM/FM and AFM/FM interactions.
Nonequilibrium magnetic properties in a two-dimensional kinetic mixed spin-2 and spin-5/2 Ising system in the presence of a time-varying (sinusoidal) magnetic field are studied within the effective-field theory (EFT) with correlations. The time evolution of the system is described by using Glauber-type stochastic dynamics. The dynamic EFT equations are derived by employing the Glauber transition rates for two interpenetrating square lattices. We investigate the time dependence of the magnetizations for different interaction parameter values in order to find the phases in the system. We also study the thermal behavior of the dynamic magnetizations, the hysteresis loop area, and dynamic correlation. The dynamic phase diagrams are presented in the reduced magnetic field amplitude and reduced temperature plane and we observe that the system exhibits dynamic tricritical and reentrant behaviors. Moreover, the system also displays a double critical end point (B), a zero-temperature critical point (Z), a critical end point (E), and a triple point (TP). We also performed a comparison with the mean-field prediction in order to point out the effects of correlations and found that some of the dynamic first-order phase lines, which are artifacts of the mean-field approach, disappeared.
We studied the dynamic magnetic properties such as dynamic phase transitions, dynamic compensation temperatures, and dynamic phase diagrams in the spin-7/2 multilayer Ising system under an oscillating external magnetic field The system was simulated in the mean-field approximation using a Glauber type stochastic dynamic. The mean sublattice magnetizations’ time variations were examined to determine the system's dynamic phases. The thermal behavior of dynamic sublattice magnetizations was investigated to determine the type of dynamic phase transitions (first- or second-order) and to obtain the dynamic compensation temperatures. P−,Q−,R−,S−, and L−type compensating behaviors were seen in various types of magnetization curves. The phase diagrams are calculated in J−T, T−h, and d−T planes, for different values of the Hamiltonian parameters. The p, i, f1/2, f7/2, af7/2, and af1/2 fundamental phases, as well as the i + p, i + f1/2, af1/2 + p, af7/2 + p and i + af1/2 mixed phases. The system illustrated one, two, or three dynamic critical points (•) and E, TP, Z, and B special points.
Employing a mean-field approach, we study the stationary states of the kinetic spin-5/2 Blume–Emery–Griffiths (BEG) model under the presence of a time-varying (sinusoidal) magnetic field by using the Glauber-type stochastic dynamics. We employ the Glauber transition rates to construct the set of dynamic mean-field equations. We investigate the time variation in average order parameters to find the phases in the system, and the thermal behavior of the dynamic order parameters to characterize the nature (continuous or discontinuous) of the dynamic phase transtions and to the dynamic phase transition temperature. The dynamic phase diagrams are presented in three different planes. The phase diagrams contain the ferromagnetic-5/2, the ferromagnetic-3/2, the ferromagnetic-1/2, the ferroquadrupolar, and disordered fundamental phases. They also include the nine coexisting or mixed phases composed of binary and ternary combinations of fundamental phases that strongly depend on the interaction parameters. The phase diagrams display the critical end point, double critical end point, triple point, quadruple point, and one, two, or three special points and the dynamic tricritical point that depends on the interaction parameters.
The dynamic magnetic behavior of the mixed-spin Ising trilayer structure, composed of a ferrimagnetically A-layer with spin-1, B-layer with spin-3/2 and a C-layer with spin-2, is investigated by using the mean-field approximation with Glauber-type stochastic dynamics. The dynamic equations describing the time-dependencies of the system are derived from the Master equation and the Glauber transition rates. The time variations of the average magnetizations and the behaviors of the dynamic magnetizations as a function of the temperature and magnetic field are investigated to find the phases and phase transition points, respectively. The dynamic phase diagrams are presented on different planes, and they exhibit several ordered phases and coexistence phase regions besides the disordered phase. Our model highlights first- and second-order phase transitions as well as the emergence of tricritical point, triple point, quadruple point, critical end point, double critical end point and multicritical point.
The dynamic magnetic properties of the mixed-spin (3/2,7/2) Blume–Capel Ising system on an interpenetrating square lattice are investigated using the path probability method in the presence of a time-dependent oscillating magnetic field. The thermal variations of the dynamic magnetizations, stationary magnetization oscillations, compensation behavior and dynamic phase diagrams are examined for both ferrimagnetic and ferromagnetic exchange interactions. The system exhibits dynamically ordered and disordered phases separated by first- and second-order dynamic phase transition lines, together with dynamic tricritical points. For the ferrimagnetic case, coexistence regions and P-, Q-, R-, [Formula: see text] and N-type compensation behaviors are observed, whereas W-, or M-type characteristics are absent within the investigated parameter ranges. Increasing the crystal-field interaction stabilizes the ordered phase, while increasing the magnetic-field amplitude promotes dynamic disordering and bistability. In contrast, the ferromagnetic case exhibits a simpler phase structure, with broader ordered regions, weaker coexistence effects and no compensation behavior. The results demonstrate that the interplay among exchange interactions, crystal-field interactions and oscillating magnetic field governs the nonequilibrium phase topology and dynamic critical behavior of the mixed-spin (3/2,7/2) system.
Kinetics of the mixed spin (1, 3/2) Ising ferrimagnetic system on the two interpenetrating square lattices with the bilinear and crystal-field interactions under an oscillating magnetic field were investigated by using the path probability method (PPM). We examined time variations in average dynamic magnetizations and obtained phases and then we investigated the thermal behaviors of dynamic magnetizations to determine the nature of the dynamic phase transitions and find their temperature values. We also constructed the dynamic phase diagrams in (d,T) and (h_0,T) planes. Dynamic phase diagrams display the paramagnetic (p), ferrimagnetic (i), and mixed phases (i+p), and one dynamic tricritical point and dynamic double critical endpoints. We found that the PPM is a more convenient method to investigate the kinetics and dynamics behaviors of ferrimagnetism.