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

TL;DR

This study investigates the dynamic phase transitions of a mixed spin-1/2 and spin-3/2 Ising ferrimagnetic model under oscillating magnetic fields using mean-field theory, revealing phase diagrams with tricritical and multicritical points.

Contribution

It introduces a mean-field kinetic analysis of a mixed-spin ferrimagnetic model with dynamic phase diagrams, including tricritical and multicritical points, under oscillating magnetic fields.

Findings

Phase diagrams show tricritical points in the (h, T) plane.

Dynamic multicritical points exist in the (d, T) plane for low h.

Multiple magnetic phases and coexistence regions are identified.

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.