Kinetics of a mixed spin-1/2 and spin-3/2 Ising ferrimagnetic model

Abstract

We present a study, within a mean-field approach, of the kinetics of a mixed ferrimagnetic model on a square lattice in which two interpenetrating square sublattices have spins that can take two values, $\sigma=\pm1/2$, alternated with spins that can take the four values, $S=\pm3/2, \pm1/2$. We use the Glauber-type stochastic dynamics to describe the time evolution of the system with a crystal-field interaction in the presence of a time-dependent oscillating external magnetic field. The nature (continuous and discontinuous) of transition is characterized by studying the thermal behaviors of average order parameters in a period. The dynamic phase transition points are obtained and the phase diagrams are presented in the reduced magnetic field amplitude $(h)$ and reduced temperature $(T)$ plane, and in the reduced temperature and interaction parameter planes, namely in the $(h, T)$ and $(d, T)$ planes, $d$ is the reduced crystal-field interaction. The phase diagrams always exhibit a tricritical point in $(h, T)$ plane, but do not exhibit in the $(d, T)$ plane for low values of $h$. The dynamic multicritical point or dynamic critical end point exist in the $(d, T)$ plane for low values of $h$. Moreover, phase diagrams contain paramagnetic $(p)$, ferromagnetic $(f)$, ferrimagnetic $(i)$ phases, two coexistence or mixed phase regions, $(f+p)$ and $(i+p)$, that strongly depend on interaction parameters.Comment: 13 pages, 6 figures, submitted to Journal of Magnetism and Magnetic Material

Phase diagrams of a nonequilibrium mixed spin-3/2 and spin-2 Ising system in an oscillating magnetic field

“…3(a) very similar to that found in earlier studies of the mixed Ising systems with spins (1/2, 1) [8,15], spins (1/2, 3/2) [16], spins (1, 3/2) [17], spins (1, 5/2) [6] and spins (1, 2) [18]. Moreover, very similar phase diagrams with Fig.…”

“…The nonequilibrium behavior of this system was also studied by using the dynamical pair approximation [9], the dynamic MC simulations and finitesize scaling arguments [10], the MC simulations and the dynamical pair approximation [11][12][13], the pair approximation with point distribution [14] and Glauber-type stochastic dynamics [15]. Very recently, we studied the dynamics of mixed-spins Ising systems with spins (1/2, 3/2) [16], with spins (1, 3/2) [17], with spins (1, 2) [18] as well as with spins (1, 5/2) [6].…”

Nonequilibrium dynamics of a mixed spin-1/2 and spin-3/2 Ising ferrimagnetic system with a time dependent oscillating magnetic field source

“…According to our simulation results, the kinetic mixed spin-1/2 and spin-3/2 Ising ferrimagnetic system including only nearest-neighbor interaction between spins, the single-ion anisotropy and external applied field does not display a dynamic multicritical behavior for a wide range of Hamiltonian parameters used in here, in contrary to the previously published molecular field investigation where dynamic first order phase transitions and dynamic tricritical points have been reported for the same model 48 . In the following analysis, in order to shed some light on the effect of the next-nearest neighbor interaction between spins-1/2 of the studied system, we give the dynamic phase boundaries in (J 2 /|J 1 | − k B T /|J 1 |) plane for some considered values of applied field amplitudes with τ = 100 in Figs.…”

Critical behavior of low dimensional magnetic systems

“…Therefore, a variety of spin mixtures, such as spin 1-spin 1/2 [15 − 22], spin 1 -spin 3/2 [23 − 25], spin 1 -spin 5/2 [26], spin 2 -spin 1/2 [15], spin 2 -spin 3/2 [27,28], spin 2 -spin 5/2 [29 − 34], spin 1/2 -spin 3/2 [15,21,35], spin 1/2 -spin 5/2 [15], spin 3/2 -spin 5/2 [17], and spin 3 -spin 3/2 [36] have been studied frequently by simulation and numerical methods. Creutz Cellular Automaton (CCA) algorithm and its improved versions are efficient to study the critical behaviors of the Ising model [36 − 40] .…”