Investigation of the kinetic behaviors of the spin systems in the neighbourhood of the equilibrium

In this thesis, we have studied the kinetic phase transition properties of the Blume-Capel model with random single ion anisotropy. By making use of the Glauber stochastic dynamics, the stationary states of the system under the effect of the oscillating magnetic field are obtained in two different approximations: mean field approximation (MFA) and effective field approximation (EFA). The time averaged magnetization acts as the order parameter and divides temperature field plane into three regions: ferromagnetic, paramagnetic and coexistence of ferromagnetic and paramagnetic phases. It is observed that the topology of the dynamical phase diagram depends strongly on the concentration of the crystal field.