Mixed Spin Research Articles

Magnetic Properties of a Mixed Spin-1/2 and Spin-7/2 Hexagonal Core-Shell Nanotube

"The magnetic properties and phase diagrams of a hexagonal nanotube with core-shell structure have been examined within the framework of the mean field theory based on the Bogoliubov inequality as well as the Monte Carlo simulation via the Metropolis algorithm. We have studied in detail the influences of the different ex- change couplings and the crystal field on the phase diagrams of the system. This study allowed us to discover the existence of interesting critical phenomena, in particular the compensation behavior. Moreover, we have investigated the behavior of the magne- tizations corresponding to each of the phase diagrams in order to verify the obtained results."

Investigation of the magnetic properties of the fullerene C30 with mixed spins: A Monte Carlo study

In this study, we employed Monte Carlo simulations to investigate the magnetic properties of C30 fullerene with mixed spins, where S = 2 and σ = 1 Ising system. We explored the ground-state phase diagrams to establish a foundational understanding of its magnetic behaviors. Magnetization and magnetic susceptibility were studied as functions of reduced temperature, highlighting the impact of mixing S and σ spins. Furthermore, we determined the evolution of the reduced transition temperature concerning the exchange interaction between S and S. Additionally, we investigated the influence of parameters such as reduced exchange interactions, temperature, and crystal field on the total magnetization. Finally, we analyzed magnetic hysteresis cycles to observe how loop surfaces change with variations in parameters, including exchange interaction, temperature, and crystal field.

Fabrication of nanofibrous membranes decorated with metal-organic frameworks for detection of pollutants in water

The environmental pollution caused by antibiotics, Fe3+ and MnO4− pollutants is becoming increasingly serious. Polyacrylonitrile (PAN) and polymethyl methacrylate (PMMA) were used and decorated with metal-organic frameworks (MOFs) to fabricated three kinds of nanofibrous membranes (NFMs) with different shapes and sizes were prepared by electrospinning technology using in situ growth method and mixed spinning method. The structures and properties of the above three kinds of NFMs were characterized. Among them, PAN@Co/Mn-MOF-74 NFM prepared by in-situ growth method based on PAN was a kind of nano-fluorescent NFM sensor with uniform structure and good fluorescence performance. It showed unique specificity and excellent sensitivity in the detection of ORN, Fe3+ and MnO4−. Compared with previously reported functionalized MOFs, PAN@Co/Mn-MOF-74 NFM has a lower limit of detection (LOD). This study provides a feasible technical route for the preparation of nano-fluorescent NFMs and the targeted detection of trace metal ions and antibiotics.

Monte Carlo study of magnetocaloric effect and magnetic properties of the nano- borophene bilayer with RKKY exchange interactions of a mixed spin 2 and 3/2

In this study, we have studied the magnetic properties and magnetocaloric effect of the nano-borophene bilayer with RKKY (Ruderman-Kittel-Kasuya-Yosida) exchange interactions of mixed spin 2 and 3/2 using Monte Carlo calculations. In the first part of this investigation, the ground state phase diagrams for zero temperature are reported and discussed. We also determined the critical temperature for varying the number of non-magnetic layers (NML) and the interacting couplings Jss. In the second part, we investigated the influence of the parameter NML, the exchange couplings Jss and Jσσ, and the crystal field on the total magnetizations and the magnetic hysteresis loop. The specific heat and magnetic entropy changes versus of the temperature under the effect of different external magnetic fields and the parameter Jss. Finally, we analyzed the relative cooling power (RCP) for distinct external magnetic field and Jss.

Blume–Emery–Griffiths model for mixed spin (1, 5/2) calculated by mean-field approximation

Blume–Emery–Griffiths model for mixed spin (1, 5/2) calculated by mean-field approximation

Magnetic properties and hysteresis loops of mixed spin - (3/2, 1) in core-shell hexagonal nanotube: comparative study of mean-field theory and Monte Carlo simulation

Based on the Ising model, Monte Carlo simulation (MCS) and the Mean- field approximation (MFA) were used to examine the magnetic properties and the phase diagram of a ferrimagnetic mixed-spin (2,3/2) hexagonal Ising nanotube with core-shell structure. The effects of exchange interactions ( ) and the single-ion anisotropies ( ) on the magnetization of the total system, the two sublattices and the hysteresis loops have been discussed in detail. The phase diagrams under the effect of different parameters have been provided. The results demonstrate the emergence of compensation phenomena as well as the second-order phase transitions. Multiple behaviors of hysteresis loop, including single and triple hysteresis loops, were identified as a result of competitions between various parameters.

Study of the Mixed Spin Ising Nanowire with Random and Dilute Crystal Field

The mixed spin Ising nanowire with random and dilute crystal fields has been explored based on the finite cluster approximation. Much concern has been addressed in treating the effects of the randomness with two distribution types of the crystal field on the phase diagrams. It has been demonstrated that for a low random crystal field D marked by the fluctuation d, all transition lines are of second order and are not particularly sensitive to the fluctuation; whereas, for high values of D, the transition temperature depends on the fluctuation and may display tricritical points. Under the effect of the dilute crystal field, according to the surface shell coupling strength, the tricritical behavior occurs exclusively for higher values of the concentration p where a large majority of spins are influenced by the crystal field. All these behaviors have been confirmed by examination of magnetizations.

An analysis of magnetic and hysteresis characteristics of a mixed spin Ising-type borophene monolayer

In recent years, borophene has developed into an incredibly promising magnetic material that is essential to many industries including superconductivity and fuel cells. In this paper, using Monte Carlo simulation, the ground-state phase diagrams and magnetic properties of an Ising-type borophene monolayer are explored specifically. The results show that induced by crystal field and exchange coupling, the second-order magnetic phase transitions and the compensation temperature are obtained. Additionally, the multiple compensation temperatures and multi-loop hysteresis characteristics are observed, which are vital in multiple magnetic recording.

Calculation of Thermodynamic Quantities of 1D Ising Model with Mixed Spin-(s,(2t − 1)/2) by Means of Transfer Matrix

In this paper, we consider the one-dimensional Ising model (shortly, 1D-MSIM) having mixed spin-(s,(2t−1)/2) with the nearest neighbors and the external magnetic field. We establish the partition function of the model using the transfer matrix. We compute certain thermodynamic quantities for the 1D-MSIM. We find some precise formulas to determine the model’s free energy, entropy, magnetization, and susceptibility. By examining the iterative equations associated with the model, we use the cavity approach to investigate the phase transition problem. We numerically determine the model’s periodicity.

Monte Carlo Study on the Magnetic Properties of the Silicene–Germanene Junction-Like Nanostructure

In this work, we study the ground state phase diagrams and the magnetic properties of the mixed spins ([Formula: see text], [Formula: see text]) of the silicene–germanene junction-like nanostructure. In the first step, the ground state phase diagrams have been established to show the more stable configurations corresponding in different physical parameter planes. Besides, we have used the Monte Carlo simulations in order to study the magnetization and the susceptibility as a function of the temperature and the exchange coupling interaction and external magnetic field effects. Finally, we have presented and discussed the hysteresis cycles for specific values of the studied physical parameters.

Dynamic hysteresis curves in a mixed spin ternary alloy system under the time-dependent magnetic field

The dynamic hysteresis features in mixed spins- ternary alloy system with formula was examined through Glauber-type stochastic dynamic and mean-field theory. The system includes two interpenetrating lattices, one has spin- components, while the other includes a random distribution of spin- and spin- compounds. The effect of Hamiltonian parameters on the dynamic hysteresis behavior was investigated in detail and observed that the physical characteristics have a significant impact on the shape and quantity of hysteresis loops. We compared our findings with other theoretical and experimental investigations; a high level of agreement is obtained.

Monte Carlo study of magnetic and magnetocaloric properties of the graphene alternate layers of a ferrimagnetic mixed spins S = 3/2 and σ = 2

Monte Carlo study of magnetic and magnetocaloric properties of the graphene alternate layers of a ferrimagnetic mixed spins S = 3/2 and σ = 2

Kinetic study on sandwiched trilayer with square lattices in the form of mixed spin$$-(1/\mathrm{2,1},1/2)$$

Kinetic study on sandwiched trilayer with square lattices in the form of mixed spin$$-(1/\mathrm{2,1},1/2)$$

Magnetic properties and magnetocaloric effects of the graphullerene-like 4-(Mg4C60) nanostructure: A Monte Carlo study

This work presents a study of the magnetic and magnetocaloric properties of mixed spins ([Formula: see text], [Formula: see text]) in a Graphullerene-like nanostructure. Monte Carlo simulations (MCs) were conducted using the Metropolis algorithm in the Blume–Capel model. The ground state phase diagrams were established and illustrated for different physical parameters. Additionally, the corresponding magnetizations, susceptibilities, specific heat, Binder cumulant, magnetic and change entropies were examined versus temperature. The critical temperature was determined, and hysteresis cycles were presented for specific physical parameter values. The results suggest that the structure shows potential as a candidate for magnetic refrigeration.

Compensation and reentrant behaviors in a graphene-like nanoribbon with zigzag and armchair edges

Graphene-like nanoribbon structures (GNRs) in which singular magnetic properties emerge because of the graphene-cutting process, may offer unique opportunities for future technological development such as spintronics. Using the finite cluster approximation, research has been implemented on some magnetic and critical characteristics of a mixed spin-3/2 and spin-1 Ising ferrimagnetic graphene-like nanoribbon with two typical edges, namely armchair, and zigzag. We investigate the influences of such aspects as crystal fields, exchange couplings, and temperature on phase diagrams and magnetizations. Tricritical as well as compensation behaviors have been demonstrated under the effect of the above physical parameters. In particular, only armchair GNR may exhibit double compensation points. Meanwhile, an unexpected reentrant transition has been discovered for both GNRs, which is mainly due to the finite size effect.

Mixed Spin Ising Ferrimagnetic System in the Oguchi Approximation

It has been investigated an Ising ferrimagnet with mixed spin-2 and spin-5/2 and various crystal field parameters on a body-centered cubic lattice. In this research paper, ferrimagnetic compensation temperatures and phase transitions to clarify the characteristic features, in a series of molecular-based magnets AFeIIFeIII(C2O4)3[A=N(n-CnH2n+1)4, n=3-5] are examined in the Oguchi approximation (OA). The spin crystal domain dependence of compensation behavior acting on ions contain the Oguchi lattice, is mainly studied. It is discovered, specifically, that magnetic anisotropies in the disordered for the two sublattices of the model depend on the negative values of the crystal fields to produce a characteristic ferrimagnetic behavior. For DA/|J|=-1.5 and DB/|J|=-5.5, there are two compensation points are induced at an ordered phase(2,-1.5).

Compensation temperatures and hysteresis loops of the ferrimagnetic bilayer kagome lattice with RKKY interaction

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 (Da, Db), the interlayer exchange coupling (JR) and the intralayer exchange coupling (Jb) are explored using Monte Carlo simulation. The results demonstrate that the compensation temperature (Tcomp), weaker Da and Jb, and stronger Db, 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.

Electrocaloric effect and ferroelectric properties of the graphene bilayer with mixed spins S=5/2 and σ=2: A Monte Carlo simulations

Monte Carlo simulations are utilized to investigate the electrocaloric and ferroelectric properties of a bilayer graphene with mixed spins S = 5/2 and σ = 2. Ground state phase diagrams are provided for several physical parameters. Additionally, the effects of exchange couplings (S-S), (σ-σ), and the crystal field on partial and total polarizations, electric susceptibilities, and electric hysteresis loops have been investigated. Critical temperatures for the graphene bilayer have been determined. The influence of an external electric field on specific heat change, electric entropy change, and relative cooling power (RCP) has been studied. This research holds potential benefits for the design of refrigeration devices and the evaluation of their efficiency.

Phase transitions of a mixed spin ferrimagnet in high temperatures

In this research paper molecular mean field theory (MMFT) has been investigated based on Gibbs-Bogoliubov free energy function of a ferromagnetic mixed spin-3 and spin-5/2 Blume-Capel model with different magnetic crystal fields. The free energy of the proposed ferrimagnet has been evaluated depending on the trial Hamiltonian operator. Minimizing the free energy, one may induce characteristic features of the longitudinal magnetizations, phase transitions and spin compensation temperatures, in the ranges of low temperatures, respectively. In particular, we study the effect of crystal field domains on the critical phenomena for the proposed model. The sublattice magnetization dependence of freerenergy function has been discussed as well. Our results predict the existence of multiple spin compensation sites in the disordered Blume-Capel Ising system for a simple cubic lattice.

Magnetic properties and hysteresis behavior of a mixed spin-3/2 and spin-3 Ising ferrimagnetic system in a graphene monolayer

Using the mean field approximation (MFA), we have successfully investigated the magnetic properties of the mixed spin Sj=±3,±2,±1,0 and σi=±32,±12 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 JA (interaction between spins σi), is greater than a certain minimum value JAmin. We have also shown that, for fixed values of the anisotropies, the relation between JAmin and the exchange interaction JB (interaction between Sj), 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.