Critical and compensation behavior of a mixed spin-3/2 and spin-5/2 Ising ferrimagnetic system in a graphene layer

The magnetic properties of an anti-ferromagnetic and ferrimagnetic mixed spin-1/2 and spin-5/2 Ising model with a crystal field in a longitudinal magnetic field on the honeycomb (z=3) and square lattice (z=4) are studied by using the effective-field theory with correlations. The ground state phase diagram of the model is obtained in the longitudinal magnetic field ( h ) and a single-ion potential or crystal-field interaction ( Δ ) plane. We also investigate the thermal variations of the sublattice and total magnetizations, and present the phase diagrams in the ( Δ / | J | , k B T / | J | ) plane. The phase diagrams have one, two or even three compensation temperatures depending on the values of the crystal-field interaction. Moreover, the susceptibility, internal energy and specific heat of the system are numerically examined, and some interesting phenomena in these quantities are found due to the applied longitudinal magnetic field.

Magnetic properties of an anti-ferromagnetic and ferrimagnetic mixed spin-1/2 and spin-5/2 Ising model in the longitudinal magnetic field within the effective-field approximation

Godoy et al. (Phys. Rev. B 69, 054428, 2004) presented a study of the magnetic properties of a mixed spin (1/2,1), Ising ferrimagnetic model on a hexagonal lattice without an oscillating magnetic field. They employed dynamic mean-field calculations and Monte Carlo simulations to find the compensation point of the model and to present the phase diagrams. It has been found that the N-type compensation temperature appears only when the intrasublattice interaction between spins in the σ sublattice is ferromagnetic. Moreover, the system only undergoes a second-order phase transition. In this work, we extend the study a dynamic compensation temperature of a mixed spin-1/2 and spin-1 Ising ferrimagnetic system on a hexagonal lattice in the presence of oscillating magnetic field within the framework of dynamic mean-field calculations. We find that the system displays the N-type compensation temperature. We also calculate dynamic phase diagrams in which contain the paramagnetic, ferrimagnetic, nonmagnetic fundamental phases and two different mixed phases, depending on the interaction parameters and oscillating magnetic field. The system also exhibits tricritical and reentrant behaviors.

Mixed-Spin Ising Model in an Oscillating Magnetic Field and Compensation Temperature

We perform Monte Carlo simulations in order to study the magnetic properties of the mixed spin-S = ± 3/2, ± 1/2 and spin-σ = ± 5/2, ± 3/2, ± 1/2 Ising model. The spins are alternated on a square lattice such that S and σ are nearest neighbors. We found that when the Hamiltonian includes antiferromagnetic interactions between the S and σ spins, ferromagnetic interactions between the spins S, and a crystal field, the system presents compensation temperatures in a certain range of the parameters. The compensation temperatures are temperatures below the critical point where the total magnetization is zero, and they have important technological applications. We calculate the finite-temperature phase diagrams of the system. We found that the existence of compensation temperatures depends on the strength of the ferromagnetic interaction between the S spins.

https://iopscience.iop.org/article/10.1088/0953-8984/23/17/176003/pdf

Magnetic behavior of a mixed Ising 3/2 and 5/2 spin model

Mixed spin- {1}/{2} and spin- {3}/{2} Ising system in a longitudinal magnetic field

We present a numerical study based on a Monte Carlo algorithm of the magnetic properties of a mixed Ising ferrimagnetic model on a cubic lattice where spins a = ±1/2 and spins S = 0, ±1 are in alternating sites on the lattice. We carried out exact ground state calculations and employ a Monte Carlo simulation to obtain the finite-temperature phase diagram of the model. A compensation point appears when the next-nearest-neighbor interaction between the spins a = ±1/2 exceeds a minimum value. We found a strong dependence of the compensation temperature with the interactions in the Hamiltonian, particularly the crystal and the external field. An applied field can change the range of values of the compensation temperature from zero up to a maximum value that depends on the field.

Numerical Study of a Three-Dimensional Mixed Ising Ferrimagnet in the Presence of an External Field

We present a numerical study based on Monte Carlo algorithm of the magnetic properties of a mixed Ising ferrimagnetic model on a cubic lattice where spins $\sigma =\pm 1/2$ and spins $S=0,\pm 1$ are in alternating sites on the lattice. We carried out exact ground state calculations and employ a Monte Carlo simulation to obtain the finite-temperature phase diagram of the model. A compensation point appears when the next-nearest-neighbor interaction between the spins $\sigma =\pm 1/2$ exceeds a minimum value. We found a strong dependence of the compensation temperature with the interactions in the Hamiltonian, particulary the crystal field and the external field. An applied field can change the range of values of the compensation temperature from zero up to a maximum value that depends on the field.

We perform numerical studies of a three dimensional Ising mixed model at different concentrations of quenched non magnetic impurities. Our preliminary results indicate that both, the compensation temperature and the temperature that signal the transition from an ordered to a disordered phase, decrease linearly with the concentration of impurities, for concentrations below 30%. For percentages of impurities above 30% the compensation temperature disappears.

Nuri Hurtado

Papers

Numerical Study of a Three-Dimensional Mixed Ising Ferrimagnet in the Presence of an External Field

Numerical Study of a Three-Dimensional Mixed Ising Ferrimagnet in the Presence of an External Field

Ferrimagnetos de Ising con Diluci\'on