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Monte Carlo simulation is used to study the magnetic properties of mixed spin (3/2, 1) disordered binary alloys on simple cubic, hexagonal and amorphous magnetic ultra-thin films with 18 × 18 × 2 atoms. To this end, at the first approximation, the exchange coupling interaction between the spins is considered as a constant value and at the second one, the Ruderman–Kittel–Kasuya–Yosida (RKKY) model is used. Effects of concentration, structure, exchange interaction, single ion-anisotropy and the film size on the magnetic properties of disordered ferromagnetic and ferrimagnetic binary alloys are investigated. Our results indicate that the spontaneous magnetization and critical temperatures of rare earth-3 d transition binary alloys are affected by these parameters. It is also found that in the ferrimagnetic state, the compensation temperature ( T com ) and the magnetic rearrangement temperature ( T R ) appear for some concentrations. [ABSTRACT FROM AUTHOR]

A hexagonal nanowire consisting of a ferromagnetic spin– 1 2 core and spin– 3 2 outer shell coupled with ferrimagnetic interlayer coupling has been studied by the use of the Monte Carlo simulation based on the heat bath algorithm. Particular emphasis is given to the effects of the size, the crystal field, the shell and the interface coupling constants on the critical and the compensation phenomenon. Some interesting behaviors have been observed which include the first and second order phase transitions. The isolated critical points are also observed. We have also found that the system exhibits the compensation phenomenon for appropriate values of the system parameters. The critical exponent has also been calculated. [ABSTRACT FROM AUTHOR]

We performed the Monte Carlo simulation (MCs) in order to study the magnetic properties and the critical behavior of Sr 2 CrMoO 6 . Within this magnetic oxide, the Cr 3+ and Mo 5+ ions form two interpenetrating ferromagnetic sublattices with opposite spins directions (Cr 3 + up and Mo 5+ down). The exchange interaction between these sublattices is assumed to be ferrimagnetic. The effects of the system parameters on critical temperatures and as a result on the phase diagrams are shown by using reduced values of parameters. The phase transitions and the magnetic stability are investigated in the framework of Ising model. For specific values of the system parameters, the existence of a compensation point is shown. Furthermore, to investigate the critical behavior, the critical exponents are calculated, they indicate that the compound belongs to a three dimensional Ising universality class. The reduced transition temperature is also found. [ABSTRACT FROM AUTHOR]

• The mixed spin Ising model is generally used as a modeling tool to study ferrimagnetism. • Monte Carlo simulation to study the critical and the compensation behaviors of a cubic lattice considering a mixed spin- 3/2 and spin-1 Ising ferrimagnetic model. • The presence of crystal and external magnetic fields is not sufficient to generate the compensation phenomenon in a mixed spins. In this study, we perform Monte Carlo simulations to study the magnetic properties of a mixed Ising model on a cubic lattice where spins S i A = 1 and σ J B = 3/2 are located in sublattice A and B, respectively. The proposed Hamiltonian includes coupling to nearest-neighbors interactions, next-nearest-neighbors interactions, crystal fields D S and D σ and external magnetic field h. We perform exact ground-state calculations for our model. The obtained results show the behavior of the critical temperature with the presence of the compensation temperatures under a certain range of parameters. Particularly, we found that the existence of compensation temperatures depends on the strength of the coupling to the next nearest neighbors between the S i A spins and between the σ J B spins, and it appears in a certain range of values of the external magnetic and crystal field of different spins. [ABSTRACT FROM AUTHOR]

Abstract: In this work, we have used Monte Carlo Simulation technique (MCS) and effective field theory (EFT) to study the critical and the compensation behaviors of a ferrimagnetic cylindrical nanowire. The system consists of a ferromagnetic spin S A =1/2 core and a ferromagnetic spin S B =1 surface shell coupled with an antiferromagnetic interlayer coupling J 1 to the core. The effects of the uniaxial anisotropy, the shell coupling and the interface negative coupling on both the critical and compensation temperatures are investigated. [Copyright &y& Elsevier]

Abstract: A Monte Carlo Simulation has been used to study the critical behavior of the magnetic spin-1 Ising nanowire on an hexagonal lattice structure. Our system consists of a ferromagnetic core with two shells, coupled antiferromagnetically with a surface shell. The effects of the crystal field, the shell and the core/shell interactions on the behavior of the system are examined. We found that the system exhibits one or two compensation points, the first and the second order transitions. Moreover, we have obtained that the critical point depends on the shell coupling. [Copyright &y& Elsevier]

In this paper, we have examined in detail the behavior of magnetic properties, hysteresis loops, and compensation phenomenon of a ferrimagnetic mixed spin- (3 ∕ 2 , 2) hexagonal Ising nanowire with alternate layers within the Monte Carlo method based on the Metropolis algorithm. The effect of longitudinal crystal field and exchange coupling constants on the total and the sublattice magnetizations, susceptibilities, specific heat, internal energy, as well as hysteresis loops are investigated for particular parameters. The obtained résults showed different interesting magnetic phenomena, such as seven and triple hysteresis loops at low temperatures, and one or double compensation temperatures under certain parameter values. Our outcomes are also compared with various experimental and theoretical studies. • A hexagonal mixed spin-3/2 and spin-2 Ising ferrimagnetic nanowire with alternate layers, within Monte Carlo simulation techniques. • The effects of the longitudinal crystal fields, the exchange coupling constant, and the temperature on the thermodynamic and magnetic properties and the hysteresis loops were examined in detail. • The seven and triple hysteresis loops at low temperatures, and double compensation temperatures under certain physical parameters. [ABSTRACT FROM AUTHOR]

Magnetic and thermodynamic properties of the zigzag graphene nanoribbon described by Ising model have been studied within Monte Carlo simulation. The system exhibited interesting and rich magnetization plateaus behaviors at low temperature, which is sensitive to the exchange coupling and the anisotropy. In certain parameters, the depressed saturation magnetization, spin-flip or spin-flop has been found on the magnetization curves. The peaks on the susceptibility and specific heat curves originate from competition among the magnetic field, the exchange couplings and anisotropies. The spin configurations of the zigzag graphene nanoribbon can be modulated by the anisotropies. Our results can provide an opportunity for the design of a new type random access memory by using zigzag graphene nanoribbon. • Ising model of zigzag graphene nanoribbon is suggested. • Magnetic properties of the system have been studied. • spin-flip or spin-flop has been found on the magnetization curves. [ABSTRACT FROM AUTHOR]