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We proposed a ferrimagnetic mixed-spin (1, 3/2) Ising model to study the magnetic behaviors of a graphene ladder-type chain structure by means of Monte Carlo simulation. Induced by different physical parameters, the system can display interesting magnetic behaviors such multiple saturation magnetization values, double-peak susceptibility curves, and multi-cycle hysteresis loops. The results illustrate that crystal-field, exchange coupling and external magnetic field show significant impacts on the magnetic properties of the system. • A mixed-spin (1, 3/2) Ising model was proposed to describe a ferrimagnetic graphene ladder-type chain structure. • Magnetization, magnetic susceptibility, and internal energy were studied by Monte Carlo method. • The phase diagrams of the blocking temperature in three-dimensional space was given. • Multi-cycle hysteresis behaviors were discovered caused by various parameters. [ABSTRACT FROM AUTHOR]

The probability distribution technique, exploited within the framework of effective field theory and the Ising model, was used to study the magnetic and thermal properties of a nanowire assimilated to a hexagonal shaped system of a core–shell structure and with mixed spins (3 / 2 , 2) , respectively. The coupling between core and shell is ferrimagnetic. Under certain physical parameter values, the nanowire exhibits the compensation behavior. The hysteresis behavior was investigated in the presence of an external magnetic field by magnetizing and demagnetizing the nanowire, as well as the effects of single ion anisotropy, ferrimagnetic exchange interactions and temperature on hysteresis loops. The dependence of the shapes of loops on the physical parameters of the system has been elucidated. At low temperatures, the nanowire exhibits triple, quadruple, quintuple, sextuple, septuple and nonuple hysteresis loop behaviors, which have important technological applications. Furthermore, the thermodynamic properties of the nanowire was also studied by evaluating the susceptibility, the internal energy and specific heat for a variety of system physical parameters. [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]

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]

In this study we used the path probability method (PPM) to calculate the dynamic phase diagrams of a ferrimagnetic mixed spin-(1/2, 1) Ising system under an oscillating magnetic field. One of the main advantages of the PPM over the mean-field approximation and the effective-field theory based on Glauber-type stochastic dynamics is that it contains two rate constants which are very important for studying dynamic behaviors. We present the dynamic phase diagrams in the reduced magnetic field amplitude and reduced temperature plane and the twelve main different topological types of the phase diagrams are obtained. The phase diagrams contain paramagnetic (p), ferrimagnetic (i) and i + p mixed phases. They also exhibit a dynamic tricritical and reentrant behavior as well as the dynamic double critical end point (B), critical end point (E), quadruple point (QP) and triple point (TP). The dynamic phase diagrams are compared and discussed with the phase diagrams obtained in previous works within the mean-field approximation and the effective-field theory based on Glauber-type stochastic dynamics. [ABSTRACT FROM AUTHOR]

Nonequilibrium phase transition properties of a mixed Ising ferrimagnetic model consisting of spin-1/2 and spin-3/2 on a square lattice under the existence of a time dependent oscillating magnetic field have been investigated by making use of Monte Carlo simulations with a single-spin flip Metropolis algorithm. A complete picture of dynamic phase boundary and magnetization profiles have been illustrated and the conditions of a dynamic compensation behavior have been discussed in detail. According to our simulation results, the considered system does not point out a dynamic compensation behavior, when it only includes the nearest-neighbor interaction, single-ion anisotropy and an oscillating magnetic field source. As the next-nearest-neighbor interaction between the spins-1/2 takes into account and exceeds a characteristic value which sensitively depends upon values of single-ion anisotropy and only of amplitude of external magnetic field, a dynamic compensation behavior occurs in the system. Finally, it is reported that it has not been found any evidence of dynamically first-order phase transition between dynamically ordered and disordered phases, which conflicts with the recently published molecular field investigation, for a wide range of selected system parameters. [ABSTRACT FROM AUTHOR]

The effective-field theory with correlations based on Glauber-type stochastic dynamic is used to study the dynamic compensation behavior of the mixed spin-1 and spin-3/2 ferrimagnetic Ising model. The system is a layered honeycomb structure in which two kinds of spins (spin-1 and spin-3/2) occupy sites alternately. This is related to the experimental works of a molecular-based magnetic multilayer film, AM II Fe II ( C 2 O 4 ) 3 ( A = N ( n − C n H 2 n + 1 ) 4 , M II = Mn,Fe ) . The system is in the presence of a sinusoidal oscillating magnetic field and the Glauber dynamic is used to describe the time evolution of the system. The effects of the interlayer coupling and a crystal-field constant of the spin-1 sublattice on the compensation temperature are investigated. Dynamic phase diagrams, including the compensation points are presented. Besides second-order phase transition, lines of first-order phase transition, the dynamic tricritical point, the dynamic zero-temperature critical point and the multicritical point are found. The dynamic tricritical point, the dynamic compensation point and the non-magnetic phase predicted by the mean-field theory are confirmed by the effective-field theory. [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]

• The graphene-like quantum dots with mixed-spin (3/2, 5/2) have been investigated. • The magnetic and thermodynamic behaviors have been explored. • The turnover phenomenon has been found. • The triple-loop behavior has been observed. Based on the Monte Carlo simulation, we have investigated the magnetic and thermodynamic behaviors of the graphene-like quantum dots described by a ferrimagnetic mixed-spin (3/2, 5/2) Ising model. The curves of the magnetization, magnetic susceptibility, internal energy and the specific heat as a function of temperature have been given under various physical parameters. The interesting turnover phenomenon has been found owing to the competition between the crystal field and temperature. It is found that the value of the blocking temperature increases with decreasing the crystal field or increasing the exchange coupling and external magnetic field. We have also investigated the hysteresis loops and found the impossibility of the triple-loop hysteresis behavior for certain parameters. The area of the hysteresis loops can be improved by increasing the exchange coupling and decreasing the absolute values of the crystal field and temperature. [ABSTRACT FROM AUTHOR]

• Dynamic phase transitions of the mixed spin (1/2, 3/2) system are investigated by the path probability method. • The system undergoes two successive phase transitions in some cases. • The system exhibits one or two dynamic tricritical and double critical end points. • The system contains the paramagnetic, ferrimagnetic and mixed phases. • The system displays reentrant behavior for certain interaction parameter. Dynamic phase transitions (DPTs) of the mixed spin (1/2, 3/2) Ising ferrimagnetic model on the two interpenetrating square lattice with the bilinear and crystal-field interactions under a time-varying (sinusoidal) magnetic field were examined by using the path probability method (PPM). We studied stationary solutions of dynamic average magnetizations and obtained phases and then we investigated thermal behaviors of dynamic magnetizations to designate the nature of the DPTs and find the DPT temperatures. We also constructed the dynamic phase diagrams (DPDs) in two different planes. DPDs exhibit the paramagnetic (p), ferrimagnetic (i), and mixed phases (i + p), and one or two dynamic tricritical points and dynamic double critical end points. The reentrant behavior is also seen. We observed that the PPM is a more appropriate dynamic method to study the dynamic features of ferrimagnetism. [ABSTRACT FROM AUTHOR]

Magnetic and thermodynamic characteristics of Ising ferrimagnetic core-shell graphene nanoribbon with core spin −2 and shell spin 5/2 were investigated by using the effective field theory with correlations. Some characteristic phenomena have been found in the system. Different saturation magnetization and P-type and Q-type curves were found on the magnetization curves. At low temperature, the magnetization has obvious magnetization platform. Due to the results of exchange coupling, anisotropy and external magnetic field competition, the m 5 -m 7 sublattice magnetization platform presents a concave shape. The results obtained may have potential applications in the design of nanodevices. • Ising model of core-shell structure 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]

In this paper, we proposed a ferrimagnetic mixed-spin (1, 3/2) Ising model to describe the ladder-like graphene nanoribbon. Using the Monte Carlo simulation, the effects of the anisotropies, exchange couplings, longitudinal magnetic field and temperature on the magnetic and thermodynamic properties were investigated. Typical temperature dependences of thermodynamics quantities such as magnetization, susceptibility and internal energy were presented under the influence of various physical parameters. The phase diagrams of blocking temperature were obtained in the different parameter planes. In particular, we also found some interesting double hysteresis loops behavior for certain physical parameters. Our results are consistent with those obtained by some theoretical and experimental researches. • The ferrimagnetic mixed-spin (1, 3/2) Ising ladder-like graphene nanoribbon in the longitudinal magnetic field has been studied. • Magnetization, susceptibility and internal energy have been discussed. • The phase diagrams of the blocking temperature under the influence of different parameters have been obtained. • The double hysteresis loops behavior has been found for certain physical parameters. [ABSTRACT FROM AUTHOR]