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The paper studies the magnetic properties of the ternary FeCoxNi1–x alloy with mixed spins Fe(S = 2), Co(σ = 3/2) and Ni(q = 1), using Monte Carlo simulations under the Metropolis Algorithm. Firstly, we explore the ground state phase diagrams in order to identify all possible and stable configurations based on the minimisation of the system energy in different physical parameters planes. In addition, the magnetisations and the magnetic susceptibilities as a function of the temperature have been studied. Moreover, the effects of the crystal field, the exchange coupling parameters on the magnetizations and the hysteresis loops have been investigated for different values of the concentration ratio x of the Co atoms. It is found that the ratio x affects strongly the magnetisation, the susceptibility, the transition temperature and the hysteresis loops of the studied system. [ABSTRACT FROM AUTHOR]

In this work, the Monte Carlo simulations have been performed to investigate the magnetic properties of the kesterite and the stannite nanostructures with mixed spins. The Blume–Capel model has been adopted to study the Cu2ZnSnSe4 nanostructures. Furthermore, we have examined different transitions as a function of the temperature, the crystal field, and the exchange coupling interactions. Also, the behavior of the magnetizations and magnetic susceptibilities are investigated as a function of the different physical parameters. A comparison of the magnetic properties of each nanostructure has been studied and discussed. [ABSTRACT FROM AUTHOR]

Monte Carlo simulations at low temperature under the Metropolis algorithm have been used to investigate the behavior of the magnetization plateaus of the honeycomb nanolattice with mixed spins (σ-3/2 and S-5/2) by varying the crystal field (d), the exchange coupling interactions ( r 1 and r 2 ) and the dilution concentration (c). We examine the behavior of the magnetization plateaus for different physical parameters and we explore the critical (hC1, hC2, hC3) and the saturation (hS) magnetic fields. Furthermore, the studied honeycomb nanolattice shows four magnetization plateaus behaviors at low temperature. Besides, increasing the dilution concentration parameter is very important to find the new magnetization plateaus. [ABSTRACT FROM AUTHOR]

Monte Carlo simulation has been used to study the behavior of the magnetization plateaus of the bi-layer graphyne like-structure with spin-2 and spin-5/2 by varying different physical parameters. We start by examining the ground state phase diagrams for zero temperature to establish the stable phases. Besides, we investigate the behavior of the magnetization plateaus for different physical parameters and we explore the critical (hC) and the saturation (hS) magnetic fields. Indeed, our Monte Carlo simulations, have been performed to deduce the ground state phase diagrams for t = 0 and the magnetization plateaus for t > 0 for the bi-layer graphyne like-structure in different planes of the reduced physical parameters (d, t, r 2 and r 1 ). The results show that among 30 possible configurations only 18 can be stable. Besides, the system shows multiple magnetization plateaus behaviors for low temperature. The behavior of the critical (hC) and the saturation (hS) magnetic fields by varying different physical parameters has been outlined. [ABSTRACT FROM AUTHOR]

Using Monte Carlo simulations under the Metropolis algorithm, we study the dilution effect on the magnetic properties in a bi-layer borophene structure. The system is formed by two layers, where each layer contains two sub-lattices of 210 atoms (with mixed spins σ = 3/2 and S = 5/2). The ground-state phase diagrams are presented in different physical parameter planes. Besides, the thermal variation of the total and partial magnetizations and susceptibilities are reported by applying Monte Carlo method. Furthermore, the dilution effect of the S spins and/or σ spins is investigated. It is found that the dilution affects the magnetizations and the hysteresis loops of the studied system strongly. [ABSTRACT FROM AUTHOR]

The effects of single-ion anisotropies and an external magnetic field on the magnetization of the mixed-spin (7/2, 3/2) ferrimagnetic Ising system are investigated within Monte Carlo simulation. Under certain values of the physical parameters, multiple hysteresis loop behaviors such as double, triple, and quintuple hysteresis cycles have been observed. Particularly, the superparamagnetic phase has been shown. The ground-state phase diagrams are presented. [ABSTRACT FROM AUTHOR]

Abstract In the present work, we use Monte Carlo simulations (MCS) to study the ferrimagnetic of the mixed spin-1 and 3/2 Blume-Emery-Griffiths (BEG) model on a honeycomb lattice. The ground state phase diagram has been obtained for T = 0 whereas at non vanishing, total and partial magnetizations have been calculated. Moroever, we have presented the results of phase diagrams depending on different parameters: exchange coupling paramaters (r 1 and r 2), crystal field (d 1 and d 2), biquadratic coupling interaction (k) and external magnetic field (h). On the other hand, the compensation temperature and hysterisis cycle have been established. Highlights • Ground-state phase diagrams have been determined. • Magnetic properties of mixed spin-1 and spin-3/2 have been studied. • Critical temperature has been deduced. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate and determine the magnetic properties and the magneto-caloric effect of the system MnAs with the spin moment ( S = 2). To attain this aim, we first use Ab initio method to determine the density of the state and exchange couplings of the compound. This stage is followed by analysis and discussion of ground-phase diagrams, and then by examination of all stable phases. To investigate further the compound, we establish the magnetic properties and the magneto-caloric effect of the compound in question by Monte Carlo simulation method in the framework of the Ising model, and consequently, we achieve a number of results such as the determination of the magnetization, the susceptibility, the specific heat and the Binder's fourth-order cumulate of the order parameter, the plotting of the effect of the exchange coupling and temperature on the hysteresis loop behaviors, the calculation of the Binder's fourth-order cumulate of energy, and finally the isothermal magnetic entropy change, adiabatic temperature change and relative cooling power (RCP) for the different external magnetic fields. [ABSTRACT FROM AUTHOR]

Being motivated by Dendrimer model with mixed spins σ=3 and S=7/2 , we investigated the magnetic nanoparticle system in this study. We analyzed and discussed the ground-state phase diagrams and the stable phases. Then, we elaborated and explained the magnetic properties of the system by using Monte Carlo Simulations (MCS) in the framework of the Ising model. In this way, we determined the blocking temperature, which is deduced through studying the partial-total magnetization and susceptibility as a function of the temperature, and we established the effects of both the exchange coupling interaction and the crystal field on the hysteresis loop. [ABSTRACT FROM AUTHOR]

In this paper, we study the magnetic properties of a tri-decorated graphene structure using Monte Carlo simulations (MCS). Indeed, we first elaborate the ground state phase diagrams and then, we found that from phases, the only stable configurations are: , , , , , , , , , , and . For low reduced temperature values, the partial magnetizations are found to be in good agreement with the corresponding ground state phase diagrams. The corresponding partial susceptibilities show a notable peak around the reduced temperature value 2.0 in the absence of the external magnetic field and crystal field . To complete this study, we present and discuss the magnetic hysteresis loops. [ABSTRACT FROM AUTHOR]

Using Monte Carlo simulations, we study the effect of the Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions in a bilayer olympicene structure, with mixed spins ( σ = 3/2 and S = 2) in the Blume-Capel model. The studied system is formed by two magnetic layers ( N and N ), separated by a number of non-magnetic layers (NM). We first elaborate the ground-state phase diagrams and then we found that from 4 × 5 = 20 phases possible, only 12 configurations are found to be stable. For low reduced temperature values, the partial magnetizations are found to be in good agreement with the corresponding ground-state phase diagrams. The critical temperature is displaced towards lower temperatures. This is due to the fact that the increasing of the number of non-magnetic layers increases the effect of the RKKY interaction. We have interpreted the behaviors of the magnetic hysteresis for this model. [ABSTRACT FROM AUTHOR]

The aim of this study is to determine and interpret the magnetic properties of a dendrimer nanoparticle system. In this model, we are inspired by a system with core-shell spins σ = 3 and S = 7/2 as the elements of this model. We first examine the ground-state phase diagrams, which are followed by the elaboration and discussion of the stable phases. Then, a theoretical study by Monte Carlo simulations (MCSs), in the framework of the Ising model, is elaborated to investigate this system. By doing so, a number of results are achieved, namely the reduced critical temperature that is determined ( T / J ) through studying the total and partial magnetizations and susceptibilities as a function of the temperature. Then, the effects of the crystal field on the total magnetizations, for the different values of the reduced exchange coupling and the reduced external magnetic field, are explored and discussed. Finally, the hysteresis loop behaviors are established and discussed. [ABSTRACT FROM AUTHOR]

In this work, we study the magnetic wetting and layering transitions in a nano-square structure. The system is consisting of particles with spins s= 1/2 and S=1 placed at the square sites. We study the effect of the exchange couplings between different spins, namely, s- s, S- s, and S- S. The wetting phenomena and layering transitions are found under the effect of the temperature and the external magnetic field, for fixed values of the exchange coupling parameters. When studying the temperature effect on the magnetizations, using Monte Carlo simulations, the ground-state phase diagrams confirm these results for very low temperatures. Over the 2 × 2 × 2 × 3 = 24 possible configurations, only 6 configurations are found to be stable in the ground-state phase diagrams. Though the model established equations are valid for any system sizes, we give results and numerical values for a fixed system size formed only by four square layers. [ABSTRACT FROM AUTHOR]

In this work, we investigate a nano-system built on a hexagonal dendrimer structure, for mixed spins σ = 2 and S = 3/2. First, we study this system in the presence/absence of both an external and crystal magnetic fields. The study of the effect of the coupling exchange interactions and the determination of the ground state phase diagrams are discussed. On the other hand, we focus our interest on the study and determination of these parameters. The elaboration and the discussion of all the stable phases have been outlined. A theoretical study by Monte Carlo simulations (MCS) in the framework of the Ising model is used to find out the understanding of the magnetic properties of this system. The obtained results by means of MCS simulations are the critical temperature and the compensation temperature. For fixed values of the coupling exchange interactions and temperature, the hysteresis loop is established, in order to complete this study. [ABSTRACT FROM AUTHOR]

Self-consistent ab initio calculations, based on the Density Functional Theory (DFT) approach and using full potential linear augmented plane wave (FLAPW) method, are performed to investigate both electronic and magnetic properties of the MnAu superlattices. Polarized spin and spin-orbit coupling are included in calculations within the framework of the antiferromagnetic state between two adjacent MnAu superlattices. Obtained data from ab initio calculations are used as input for the Monte Carlo simulations to compute other magnetic parameters. On the other hand, and within the framework of Monte Carlo simulations, we examine the magnetic properties in the binary MnAu superlattices modelized by the Mn ion with spin moment, S=5/2. The considered Hamiltonian takes into account the nearest neighbor and second nearest interactions, and an external magnetic field h. The magnetization of the MnAu superlattice is calculated versus temperature for a fixed size. The magnetic hysteresis cycle is established for T=120 K. The effect of magnetization versus the second exchange interaction ( J) are established with absence and presence of magnetic field ( h). [ABSTRACT FROM AUTHOR]

Abstract: In this work we use Monte Carlo (MC) simulations to study the magnetic properties of a double perovskite nano Sr2VMoO6, with crystal and magnetic fields. The crystal structure of Sr2FeMoO6 is constituted of two magnetic cubic sub-lattices: The sub-lattice (I) is occupied by the V3+ magnetic ions with a magnetic moment S =1, while the sub-lattice (II) is occupied by the Mo5+magnetic ions with a magnetic moment σ =1/2. A number of interesting phenomena such as the blocking temperature, the exchange interaction coupling between V3+ and Mo5+ ions, the size and temperature effects, at fixed values of the crystal field, have been investigated. On the other hand, the response of the magnetization to the field is illustrated in the hysteresis loops. [Copyright &y& Elsevier]

The magnetic properties of nanotube are investigated by Monte Carlo simulations. The nanotube is considered as a lattice of spins σ=±1/2 and S=±1,0. For each block lattice σ i and S i , the blocking temperature versus values of crystal field is estimated. The magnetization of each spin configuration is computed versus the exchange interaction between the spins of each bloc lattice in the absence and the presence of crystal field at fixed temperature. In addition, the hysteresis cycle for different temperature values in the absence and presence of the crystal field is deduced. [ABSTRACT FROM AUTHOR]

In this work, we use Monte Carlo simulations to study the magnetic properties of a nanowire system based on a honeycomb lattice, in the absence as well as in the presence of both an external magnetic field and crystal field. The system is formed with NL layers having spins that can take the values σ = ±1/2 and S = ±1,0. The blocking temperature is deduced, for each spin configuration, depending on the crystal field Δ. The effect of the exchange interaction coupling Jp between the spin configurations σ and S is studied for different values of temperature at fixed crystal field. The established ground-state phase diagram, in the plane (Jp, Δ), shows that the only stable configurations are: (1/2,0), (1/2,+1), and (1/2,-1). The thermal magnetization and susceptibility are investigated for the two spin configurations, in the absence as well as in the presence of a crystal field. Finally, we establish the hysteresis cycle for different temperature values, showing that there is almost no remaining magnetization in the absence of the external magnetic field, and that the studied system exhibits a super-paramagnetic behavior. [ABSTRACT FROM AUTHOR]

Abstract: A Monte Carlo (MC) simulation was used to observe the magnetic behavior of a superlattice Ising Model, in the presence of both an external and crystal magnetic fields. The system is made up to layers and . The effect of the exchange interaction coupling between the spin configurations and is investigated for different values of temperature at fixed values of the crystal field. We found that this parameter increases the magnetization of the system at high temperature. Also, the critical temperature is calculated, for each spin configuration as function of temperature using the MC technique. The thermal behavior magnetizations and susceptibilities are studied. Finally, the response of the magnetization to the field shows a hysteresis behavior. [Copyright &y& Elsevier]

The magnetic properties of an Ising antiferromagnetic model on a nanographene lattice which have spins that can take the values S=±3/2, ±1/2, are studied by Monte Carlo simulations. We only consider the nearest-neighbor interactions between the sites i and j. The zero field cooled and field cooled magnetizations, magnetic susceptibilities and hysteresis cycle are obtained for a nanographene structure with the effect of exchange interaction between sites i and j. The blocking temperature is also obtained for specific values of the external magnetic field. [ABSTRACT FROM AUTHOR]

Abstract: Using the mean field theory, we investigate the effect of the random crystal-field on the spin- Blume–Capel model. Several new features are found including the appearance of new order phase with the magnetization at low temperature and consequently a rich ground-state phase diagram. At finite temperature, new types of phase diagrams appear. Furthermore, we show that at low temperature a first-order transition line terminated at isolated critical points, between the ferromagnetic phases. A reentrant phenomenon is also discussed. [Copyright &y& Elsevier]

Abstract: The effect of a random surface field, within the bimodal distribution, on the layering transitions in a spin- Ising thin film is investigated using Monte Carlo simulations. It is found that the layering transitions depend strongly on the concentration p of the disorder of the surface magnetic field, for a fixed temperature, surface and external magnetic fields. Indeed, the critical concentration at which the magnetisation of each layer k changes the sign discontinuously, decreases with increase in applied surface magnetic field, for fixed values of the temperature T and the external magnetic field H. Moreover, the behaviour of the layer magnetisations as well as the distribution of positive and negative spins in each layer, are also established for specific values of , H, p and temperature T. [Copyright &y& Elsevier]

The order–disorder layering transitions, of the spin-1 Blume–Capel model, are studied using the Monte Carlo (MC) simulations, in the presence of a variable crystal field. The system exhibits tri-critical behavior and reentrant phenomena. The reentrant phenomena is found for the first k0 layers from the surface, where k0 is exactly the number of layering transitions at the ground state. This is qualitatively in agreement with mean field results. Layer magnetizations, quadrupolar and magnetic susceptibilities are calculated. The critical exponents of magnetic susceptibility of each layer are computed for N=10 and different sizes of the system. It is found that the critical exponent of a 2D layer in a film is different than the one of a free 2D layer. Indeed the critical exponent of a layer depends strongly on its position from the surface. [Copyright &y& Elsevier]

In this paper, we study the magnetic properties of ferrimagnetic mixed spins with integer σ = 2 and half-integer S = 7 / 2 in a Blume–Capel model, using Monte Carlo simulations. The considered Hamiltonian includes the first nearest-neighbors and the exchange coupling interactions on the two sub-lattices. The effect of these coupling exchange interactions, in the presence of both the external magnetic field and the crystal field, are studied. The magnetizations and the corresponding susceptibilities are presented and discussed. Finally, we have interpreted the behaviors of the magnetic hysteresis of this model. [ABSTRACT FROM AUTHOR]

A bi-layer system consisting of layers of spins (7/2, 3) in a ferromagnetic dendrimer structure, separated by a non-magnetic spacer, is studied by Monte Carlo simulations. The effect of the RKKY interactions is investigated and discussed for such system. It is shown that the magnetic properties in the two magnetic layers depend strongly on the thickness of the magnetic and non-magnetic layers. The total magnetizations and susceptibilities are studied as a function of the reduced temperature. The effect of the reduced exchange interactions as well as the reduced crystal field is outlined. On other hand, the critical temperature is discussed as a function of the magnetic layer values. To complete this study we presented and discussed the magnetic hysteresis cycles. [ABSTRACT FROM AUTHOR]

• The magnetic properties of a spin Lieb nanolattice have been studied. • The dilution effect is discussed. • The Monte Carlo simulations are applied. • The magnetizations and magnetic susceptibilities have been deduced and discussed. • The magnetic hysteresis cycles of the spin Lieb nanolattice have been investigated. In this paper, we investigate the magnetic properties of the spin Lieb nanolattice for three sublattice with spins S = 1/2, σ = 3/2 and q = 1, in the presence of sites dilution. Furthermore, in order to study the effect of disorder, the spins S and/or q are diluted, while the spin σ stays pure. The work is carried out according to the Monte Carlo Simulations. We start this research by giving the total and partial magnetizations, then we present magnetic susceptibilities of the studied system. In addition, the variation of the magnetization with temperature of mixed spins (s , σ and q) with dilution is presented. The total magnetization with crystal and external fields and with dilution of mixed spins is obtained. Besides, we have presented the magnetic hysteresis cycles of spin Lieb structure, for different values of crystal-field and temperature and for different dilution values. To the best of our knowledge, no single research has been reported in the study of the dilution effect on the magnetic properties in the studied system. [ABSTRACT FROM AUTHOR]

Monte Carlo simulation has been carried out to study the magnetization of the mixed spin–5/2 and spin–7/2 Ising ferrimagnetic model on a square lattice with periodic boundary conditions. The total magnetization and the magnetizations of the two sublattices under the effects of exchange interactions and the crystal field anisotropy are studied. The ground–state diagrams are constructed. We obtained different types for the thermal dependence of magnetization. Compensation points where the global magnetization of the system vanishes have been detected for appropriate values of the system parameters. [ABSTRACT FROM AUTHOR]

The kinetics of the semi-infinite Ising model, in the presence of a time-dependent oscillating external field, is studied within the framework of the mean-field approach. We use the Glauber-type stochastic dynamics to describe the time evolution of this system. In addition to the well-known phase transitions (ordinary, extraordinary, and surface phase transitions) in the equilibrium case, a dynamical phase appears in which the bulk orders, whereas the surface is disordered. Consequently, a variety of phase diagrams is obtained. Furthermore, the system exhibits dynamical first-order phase transition. The magnetizations and phase space trajectories are given and discussed. [ABSTRACT FROM AUTHOR]

In this work, we study the magnetic properties of a nanotube core-shell like-structure using Monte Carlo simulations. The system consists of an anti-ferrimagnetic hexagonal core-shell nanotube like-structure with mixed spins σ = 1 in the core and S = 3/2 in the shell. We start by discussing the ground state phase diagrams corresponding to several physical parameters. Then the magnetizations and the susceptibilities have been analyzed. Besides, we explore the thermal magnetization behavior under the effect of the exchange coupling interactions. Furthermore, we investigate the existence of the compensation temperature resulting from the variation of the coupling coefficients. Finally, the variation of the total magnetization and total susceptibility as a function of the exchange coupling interactions and the crystal field has been discussed. • Compensation Behavior of an Anti-ferrimagnetic Core-Shell Nanotube Like-Structure. • Monte Carlo Study has been discussed. • The Monte Carlo simulations technique used to simulate. • The behavior of the Compensation temperature has been established. • A Core-shell nanotube structure has been considered. [ABSTRACT FROM AUTHOR]

In this paper, the magnetic properties of a bi-layer graphyne structure have been studied using Monte Carlo simulations. The considered system is composed of two planes of graphyne with mixed spins: σ = 7/2 and S = 1. Firstly, the ground state phase diagrams for zero temperature are reported and discussed. Secondly, the magnetic properties for the studied system are examined for non-zero temperature. The effects of exchange coupling interaction and temperature on magnetization, susceptibility and transitional temperature. Furthermore, the effects of the crystal field on total magnetization of the system have been exhibited. Finally, the effect of the ferrimagnetic parameter, temperature and crystal field on the hysteresis cycles have been determined. The obtained results have been compared with theoretical and experimental researches. • We study the magnetic properties of a bi-layer graphyne structure. • The ground state phase diagrams are presented and discussed. • The magnetic properties of a bi-layer graphyne structure using Monte Carlo simulations are investigated. • The hysteresis cycles of a bi-layer graphyne structure are analyzed. [ABSTRACT FROM AUTHOR]

The magnetic properties of a mixed spins (7/2, 1) anti-ferrimagnetic ovalene nano-structure have been investigated using Monte Carlo simulations. We start by discussing the ground state phase diagrams corresponding to several physical parameters. Then the effects of the crystal field, the exchange coupling interactions and the external magnetic field on the magnetizations, the compensation temperatures and the hysteresis behaviors have been studied. Interesting results have been found, especially, the appearance of two compensation temperatures and their behaviors according to different physical parameters. • Magnetic properties of ovalene nano-structure are studied using Monte Carlo simulations. • Ground state phase diagrams of ovalene nano-structure have established given. • Existence of two compensation temperatures for a special physical parameters. • Two super-paramagnetic phases are observed. • Hysteresis cycles of ovalene nano-structure have been investigated. [ABSTRACT FROM AUTHOR]