Akademik Veri Yönetim Sistemi
Chinese Journal of Physics, cilt.96, ss.63-89, 2025 (SCI-Expanded)
Herein, the static and dynamic properties of the spin-1 Blume–Emery–Griffiths model for two sublattices are presented with respect to spin-crossover (SCO) and magnetization in the presence of an external magnetic field. We use the lowest approximation of the cluster variation method to investigate the static properties of SCO and magnetization. Using the solutions of self-consistent equations, we present the thermal behaviors of high-spin fraction (nHS) and magnetization for different parameters, including the magnetic interaction and quadrupolar (elastic) interaction parameters. In addition, the properties of SCO and magnetizations for equivalent and nonequivalent sublattices with two-step transition and thermal hysteresis loops are presented. The model incorporates quadrupolar intersublattice interaction parameters between two sublattices. Regarding nonequivalent sublattices, our calculation shows that when the values of the intersublattice interaction parameters are higher than those of the intrasublattice parameters, a two-step SCO with a hysteresis loop occurs. This phenomenon occurs at lower temperatures as the value of this parameter increases. However, multistep transition states for SCO and magnetization are observed to be a function of varying external magnetic fields at constant temperatures. Considering the magnetic and quadrupolar interaction parameters, the dynamic properties of the system are studied using the path probability method. In this model, we obtain the relaxation curves for nHS and magnetization. The self-consistent equations of the system are solved using the Newton–Raphson or iteration method and the Runge–Kutta method.