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The electronic and the magnetic properties of the double perovskite S r 2 C r W O 6 are studied by using ab-initio density functional theory (DFT) calculations with Generalized Gradient Approximation (GGA) and Monte Carlo simulation within the framework the Ising model. This compound is formed by two magnetic cubic sublattices, one occupied by Chromium C r 3 + with spin (S = 3 / 2) and the other occupied by Tungsten W 5 + with spin (σ = 1 / 2). The density of states (DOS) and the band structure of the compound are investigated. The results show the half metallic behavior of S r 2 C r W O 6 with a total magnetic moment equal to 2 μ B . The degeneracy removed from the orbital d of the Chromium by the octahedral crystal field was discussed. The exchange couplings C r − C r and W − W are ferromagnetic, while the super exchange coupling C r − O − W is antiferromagnetic. Concerning the Monte carlo study, it is seen that the system presents interesting phenomena. In particular, the compensation behavior, the first order transition and multiple hysteresis loops have been obtained. • The electronic and the magnetic properties of the double perovskite Sr 2 CrWO 6 are studied by using DFT and MCS. • The results show the half metallic behavior of Sr 2 CrWO 6 with a total magnetic moment equal to 2μ B. • The compensation behavior, the first order transition and multiple hysteresis loops have been obtained. [ABSTRACT FROM AUTHOR]

Magnetic properties of a mixed spins (5/2,3/2) Isotropic Blume–Emery–Griffiths model (BEG) on a graphene layer have been studied within the framework of the Monte Carlo simulation. We have investigated the effects of the next nearest neighbors exchange interaction, the biquadratic exchange interaction and the longitudinal magnetic field on the critical and magnetic behaviors of the system. Interesting phenomena have been remarked. In particular, for appropriate parameters of the Hamiltonian, the system exhibits magnetization plateaus, double reentrant phenomena and compensation behavior. • Magnetic properties of a mixed spins - (5/2,3/2) Isotrope BEG model on a graphene layer have been studied by using MCS. • The system shows double reentrant phenomena. • The compensation biquadratic exchange coupling and the compensation temperature can emerge in the system. [ABSTRACT FROM AUTHOR]

Using the Monte Carlo method, we have studied the effect of the Hamiltonian parameters (the exchange couplings, the crystal and the magnetic fields) on the magnetizations, the phase diagrams and the hysteresis behavior of a hexagonal ferromagnetic or ferrimagnetic Ising core/shell nanoparticle with mixed spin-5/2 and spin-2. Interesting phenomena have been shown. In particular, the system exhibits the first order transition, the compensation temperature and the compensation crystal field. In addition, the nanoparticle presents single, double, triple and quintuple hysteresis loops. • MCS has been used to study the magnetic properties of a mixed spin-(5/2, 2) Ising core/shell nanoparticle. • The system presents a special point at which four first order transition lines are linked. • The compensation behavior and multiple hysteresis loops have been observed. [ABSTRACT FROM AUTHOR]