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We study the thermodynamic and magnetic properties of an Ising bilayer ferrimagnet. The system is composed of two interacting non-equivalent planes in which the intralayer couplings are ferromagnetic while the interlayer interactions are antiferromagnetic. Moreover, one of the planes is randomly diluted. The study is carried out within a Monte Carlo approach employing the multiple histogram reweighting method and finite-size scaling tools. The occurrence of a compensation phenomenon is verified and the compensation temperature, as well as the critical temperature for the model, are obtained as functions of the Hamiltonian parameters. We present a detailed discussion of the regions of the parameter space where the compensation effect is present or absent. Our results are then compared to a mean-field-like approximation applied to the same model by Balcerzak and Szałowski (2014). Although the Monte Carlo and mean-field results agree qualitatively, our quantitative results are significantly different. [ABSTRACT FROM AUTHOR]

• The critical temperature of FeNi and FePt alloys using Heisenberg interaction is closer to the experimental value than the Ising interaction. • The FeNi and FePt alloys prefer a ferromagnetic phase over the ferrimagnatic phase. • The Ising interaction predicts higher critical temperature for the FeNi alloy than the Heisenberg interaction. • The Heisenberg interaction predicts higher critical temperature for the FePt alloy than the Ising interaction. A Monte Carlo simulation has been used to explore the magnetic properties of L1 0 ordered FeNi and FePt binary alloys. Our Hamiltonians include Heisenberg interaction or Ising interaction. Our calculations of variations of specific heat C v , magnetic susceptibility χ and the magnetization M with the temperature T showed that predicted critical temperature for ferromagnetic phase is very close to the experimental values for these alloys. Also, thermal hysteresis loops, magnetic remanence, and the coercive field have been calculated. Moreover, the magnetic properties of the ferrimagnetic phase are presented. [ABSTRACT FROM AUTHOR]

The magnetic properties of spins -S and σ Ising model on the Bethe lattice have been investigated by using the Monte Carlo simulation. The thermal total magnetization and magnetization of spins S and σ with the different exchange interactions, different external magnetic field and different temperatures have been studied. The critical temperature and compensation temperature have been deduced. The magnetic hysteresis cycle of Ising ferrimagnetic system on the Bethe lattice has been deduced for different values of exchange interactions between the spins S and σ , for different values of crystal field and for different sizes. The magnetic coercive filed has been deduced. [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]

An effective field method has been employed to study the magnetic properties of a ferrimagnetic mixed-spin Ising trilayer nanographene structure. The system is formed by alternate layers of two different spins atoms A (spin-1) and B (spin-½) arranged in a particular fashion A – B – A for which the nearest-neighbor spins of each layer are coupled ferromagnetically (J A and J B), whereas the cross atom interaction A - B (interlayer) is antiferromagnetic (J AB). We examined the effects of interlayer (or intra-layer) exchange coupling and single-ion anisotropy on the magnetization curves of the system. We found that the antiferromagnetic inter-layers (J AB < 0) coupling and the single-ion anisotropy have a dominant factor in the occurrence of the single or the double compensation temperature. We also deeply examined the occurrence of hysteresis loops and their various unusual forms. The results obtained are discussed in detail as a function of the main parameters of the magnetic Hamiltonian. Finally, we noticed that our results are in line with other recently reported theoretical and numerical studies. • Ferrimagnetic spin mixed with nano-graphene trilayer Ising model on effective field approach has been considered. • Effects of Intra- and inter-layers exchange couplings, as well as single-ion anisotropy have been analyzed. • One or more compensation points can be obtained under special choice of intrinsic parameters. • The shape and the multi-windows hysteresis loops can be controlled through exchange or single-ion anisotropy. • Application of synthetic ferrimagnetic multilayers are outlined. [ABSTRACT FROM AUTHOR]

Magnetic properties of a trilayer nanostructure of hexagonal lattices described by the spin-1/2 Ising model are investigated via the effective-field theory (EFT) with correlations. In order to clarify the distinction between the ferromagnetic and ferrimagnetic behaviors, the total magnetization, total susceptibility, total inverse susceptibility and critical boundaries have been obtained for positive and negative interlayers couplings. From thermal variations, some magnetic compensation types are found for the ferrimagnetic system. The specificities of the susceptibilities when the magnetizations present compensation temperatures have been also studied. • Correlation identities on a nanostructure of hexagonal lattices are obtained. • From the spin correlation identities the effective-field theory is applied. • The total magnetization and total susceptibility are obtained. • The critical temperature and the compensation temperature are investigated. [ABSTRACT FROM AUTHOR]

• Critical properties of Fe-Al alloys in the bcc phase – phase diagram. • Ising model with exchange and superexchange interactions. • Monte Carlo simulations taking the effects of the Al cluster sizes. A spin-1/2 Ising model, defined in the body centered cubic lattice, is used to describe some of the thermodynamic properties of Fe p - Al q alloys, with p + q = 1. The model assumes, besides the nearest-neighbor exchange coupling, the existence of further next-nearest-neighbor superexchange interactions, where the latter ones depend on the aluminum atoms cluster size. The Ising system so considered is studied by employing Monte Carlo simulations, using a hybrid algorithm consisting of one single-spin Metropolis move together with one single-cluster Wolff algorithm allied, in addition, with single histograms procedures and finite-size scaling techniques. Quite good fits to the experimental results of the ordering critical temperature, as a function of Al concentration in the range 0 ⩽ q < 0.7 , are obtained and compared to more recent theoretical approaches done on the same alloys. [ABSTRACT FROM AUTHOR]