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• YFeO 3 have been studied with GGA and GGA+U reveal a semi-conductor and an Antiferromagnetic type-G behavior. • Magnetic anisotropy results for both approximations show that easy axis magnetization for YFeO 3 is along the c-axis. • Evaluation of the electric polarization and the magnetic transition temperature of the orthorhombic YFeO 3 has done. In this study, we have thoroughly investigated the electronic, magnetic, and electrical properties of yttrium orthoferrite using density functional theory (DFT) within the generalized gradient approximation (GGA) and the (GGA + U) approach, which incorporates the Hubbard term (U). Both approximations consistently reveal a semiconductor behavior and an antiferromagnetic behavior of type-G between the iron (Fe) ions. To delve deeper into the magnetic interactions within YFeO 3 , we have proposed a physical model. This model allows us to calculate the magnetic exchange coupling and magnetic anisotropy parameters through DFT calculations. Additionally, we have conducted computations to determine the electric polarization. Our results have shown that the electric polarization in YFeO 3 is exclusively derived from electronic polarization. We have also explored the relationship between the direction of electric polarization and the easy-axis magnetization. In our investigation, we found that both the electric polarization and easy-axis magnetization align along the c-axis in both approximations. Furthermore, we have examined the influence of the Hubbard term on the direction of polarization. To assess the magnetic temperature transition, we employed Monte Carlo simulations using the Ising model. The critical temperature, denoted as T N , obtained with the GGA approximation is found to be 726.66 K. Remarkably, this value closely matches the experimental critical temperature when compared to the critical temperature obtained with the GGA + U approximation. [ABSTRACT FROM AUTHOR]

The band alignment, intrinsic ferromagnetism, Dzyaloshinskii-Moriya interaction, magnetic anisotropy and critical temperature (T C) of a GdI 2 /GeC van der Waals (vdW) heterostructure were systematically investigated by first-principles calculations and Monte Carlo simulations. The proposed GdI 2 /GeC vdW heterostructure is a bipolar magnetic semiconductor with Type-I band alignment, large in-plane magnetic anisotropy energy (MAE) of − 0.912 mJ/m2 and high critical temperature of 466 K. In addition, under biaxial strains, the heterostructure transformed from semiconductor into metal, while the easy magnetization axis maintained in-plane and T C increased. The results indicated that the GdI 2 /GeC vdW heterostructure presented large MAE and high T C , having potential applications in spintronic devices. [Display omitted] ● The heterostructures is a bipolar magnetic semiconductor. ● The heterostructures with large in-plane magnetic anisotropy. ● The heterostructures with high critical temperature 466 K. [ABSTRACT FROM AUTHOR]

In this study, a bilayer Kagome lattice with RKKY interaction is described using a ferrimagnetic mixed spin-3/2 and spin-2 Ising model. Interesting compensation temperature and hysteresis loops of the system generated by various physical parameters, such as the crystal fields of sublattices (D a , D b), the interlayer exchange coupling (J R) and the intralayer exchange coupling (J b) are explored using Monte Carlo simulation. The results demonstrate that the compensation temperature (T comp), weaker D a and J b , and stronger D b , are favourable for the emergence of the compensation temperatures. Besides, under certain physical parameters, the system may exhibit triple-loop hysteresis behavior and multiple magnetization plateaus. • A ferrimagnetic mixed-spin (3/2, 2) Ising model on the bilayer Kagome lattice with RKKY interaction was proposed. • The effects of the crystal field, exchange coupling and non-magnetic layer were studied. • Magnetization, partial magnetization, and susceptibility were discussed. • Phase diagrams of the critical and compensation temperatures were obtained. • Interesting multi-loop hysteresis characteristics and magnetization plateaus were found. [ABSTRACT FROM AUTHOR]

Using the mean field approximation (MFA), we have successfully investigated the magnetic properties of the mixed spin S j = ± 3 , ± 2 , ± 1 , 0 and σ i = ± 3 2 , ± 1 2 Ising ferrimagnetic system in a graphene layer. The effects of different physical parameters, namely exchange interactions, anisotropies, external field and temperature on the critical, first-order, compensation and hysteresis behaviors have been examined. The results show that, for specific values of these parameters, interesting phenomena appeared, such as compensation and multi-loop hysteresis behavior. It was shown that the compensation phenomenon only occurs if the exchange interaction J A (interaction between spins σ i), is greater than a certain minimum value J A m i n. We have also shown that, for fixed values of the anisotropies, the relation between J A m i n and the exchange interaction J B (interaction between S j), is a linear one. In addition, we found that each of the behaviors mentioned above is sensitive to the change of a certain physical parameter. Finally, we have verified that our results are comparable with those of other works. • The effects of physical parameters on magnetic properties were examined. • The system presents a first- and second-order transition. • Compensation appears in the system for specific values of physical parameters. • The phenomenon of multi-loop hysteresis cycles is present in the system. [ABSTRACT FROM AUTHOR]

• A multi-walled mixed spin (1/2; 1; 1/2; 1) Ising nanowire with a basic hexagonal shape is built. • For ferrimagnetic and ferromagnetic sates, different magnetic properties are established. • The magnetization types and compensating behaviors are strongly influenced by different Hamiltonian settings. • Unique outcomes are discovered. Using the Effective Field Theory with correlation, we investigate the magnetic properties and the phase diagram of a mixed-spin (½, 1, ½, 1) Ising core-multi shell nanowire structure. Typical temperature dependence of the total magnetization, the core and shell magnetization for several fixed values of exchange couplings were discussed in detail. The phase diagrams of the critical and compensation temperatures were displayed in various Hamiltonian parameter planes. Our established results have been successfully compared with results from several experimental and theoretical studies. The ultimate objective is to stimulate research into the design and development of innovative nanomaterials for targeted applications. [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 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]

We applied Monte Carlo simulation to investigate the thermodynamic properties and hysteresis loops of the hexagonal core-shell nanoparticle described by a ferrimagnetic mixed-spin (3/2, 5/2) Ising model. The results revealed the significance of the single-ion anisotropy, exchange coupling, external magnetic field in dominating various thermodynamic quantities and hysteresis loops. We obtained the variation of the critical temperature with various parameters. Under certain parameter conditions, the system may exhibit rich multiple-loop hysteresis behaviors, depending on the competition among the physical parameters. An Ising model of nanoparticle with hexagonal core-shell structure is proposed. The multiple profiles and saturation values of the magnetization are discovered in the system. [Display omitted] • A ferrimagnetic hexagonal core-shell nanoparticle was proposed under an external magnetic field. • Magnetization, susceptibility, and internal energy were discussed by Monte Carlo simulation. • The compensation temperature was found under the effect of single-ion anisotropy. • Multiple-loop hysteresis behaviors were discovered due to the competition among different physical parameters. [ABSTRACT FROM AUTHOR]

We investigate the dynamic magnetic properties of the A B p C 1 − p form mixed ferro-ferrimagnetic ternary alloy. For this purpose, the system was simulated by means of a Hamiltonian including single-ion anisotropy, A and B sites interact ferromagnetically, and A and C sites interact antiferromagnetically in the presence of a time-dependent magnetic field. A ion contains S A = 3/2, B ions have S B = 1 and C ions have S C = 5/2. The phase diagrams are calculated in temperature, single-ion anisotropy, and concentration ratio parameters planes. It is found that in our dynamic system, the critical temperature was always dependent on the concentration of the ternary alloy. We show that single-ion anisotropy can be used as a control parameter like concentration to arrange the critical temperature of the ternary alloy. • The dynamic magnetic properties of the mixed ferro-ferrimagnetic ternary alloy. • The system was simulated by means of a Hamiltonian including single-ion anisotropy • The critical temperature was always dependent on the concentration of the ternary alloy. [ABSTRACT FROM AUTHOR]

The structural, electronic, and magnetic properties of the Zn x Ni 1-x Fe 2 O 4 compounds are studied using several theoretical methods such as first-principle calculations based on density functional theory (DFT+U), Monte Carlo simulations, High temperature series expansions(HTSE) combined with the Padé approximants(PA) and mean-field theory. The total magnetic moment increases and the Curie temperature decreases with Zn substitution. The gap energy results of 1.3 eV obtained using GGA+U are reasonable compared to the available experimental data. The ZnFe 2 O 4 possesses the insulating ground state and antiferromagnetic ordering. The critical exponent γ associated with the magnetic susceptibility is obtained. The dependence of the magnetization and the magnetic susceptibility on temperature is established for Zn x Ni 1− x Fe 2 O 4 using Monte Carlo study. [ABSTRACT FROM AUTHOR]