Magnetic behavior of a mixed Ising ferrimagnetic model in an oscillating magnetic field

Abstract

The magnetic behavior of a mixed Ising ferrimagnetic system on a square lattice, in which the two interpenetrating square sublattices have spins σ (±1/2) and spins S (±1, 0), in the presence of an oscillating magnetic field has been studied with Monte Carlo techniques. The model includes nearest and next-nearest neighbor interactions, a crystal field and the oscillating external field. By studying the hysteretic response of this model to an oscillating field we found that it qualitatively reproduces the increasing of the coercive field at the compensation temperature observed in real ferrimagnets, a crucial feature for magnetooptical applications. This behavior is basically independent of the frequency of the field and the size of the system. The magnetic response of the system is related to a dynamical transition from a paramagnetic to a ferromagnetic phase and to the different temperature dependence of the relaxation times of both sublattices.

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

“…Ferrimagnetic materials have, under certain conditions, a compensation temperature at which the resultant magnetization vanishes below its critical temperature 1 . Recently, it has been both experimentally and theoretically shown that the coercive field exhibits a rapid increase at the compensation point 2,3 . It is obvious that such kind of point has a technological importance 4,5 , because at this point only a small driving field is required to change the sign of the resultant magnetization.…”

Dynamics of Magnetization Reversal in Models of Magnetic Nanoparticles and Ultrathin Films

“…This nonequilibrium phase transition was first observed in numerical solutions of mean-field equations of motion for ferromagnets in oscillating fields [63,64]. Subsequently it has been observed in numerous Monte Carlo simulations of kinetic Ising systems [56,65,66,67,68,69,70,71,72,73,74,75] and in further mean-field studies [68,70,71,73,76]. It may also have been experimentally observed in ultrathin films of Co on Cu(100) [58,77].…”

Hexagonal-Type Ising Nanowire with Core/Shell Structure Designed with Half-Integer Spins: Compensation Behaviors and Phase Diagrams in the Temperature and Interaction Planes

“…Experimentally, some compensation temperature measurements in Fe 3 O 4 and Mn 3 O 4 superlattices [67] and Ni(H-COO) 2 · 2H 2 O [68] were observed. In like manner, previous studies show that at the compensation temperature, the coercivity of a material increases dramatically and at this point, only a small conductor field to invert the sign of the magnetization [64,[69][70][71][72] is required. (J 1 , , T ), (J C , , T ), and (J S , , T ) Planes…”