Critical phenomena in a two-dimensional ferrimagnetic system: Monte Carlo and Mean-Field Analysis

The critical, first order, and spin compensation behaviors of a ferrimagnetic [sing system, consisting of spins S = 3/2 and Q = 5/2 alternating on a square lattice, have been studied by Monte Carlo (MC) simulations and Mean-Field Theory (MF). The system is defined by a Hamiltonian (H) that contains ferromagnetic next-nearest-neighbors interactions between S spins (J(2)') and Q spins (J(3)'), as well as external magnetic field (h') and anisotropy (D-1', D-2') interactions. The effects of D-1' crystal and h' magnetic fields on the critical, double first order transition, and compensation phenomena are analyzed in detail. We found that the existence of a double first order phase transition depends on the temperature and the strength of h'. (C) 2019 Published by Elsevier B.V.