Different Values Of Exchange Interactions Research Articles

Ground States Phase Diagrams and Magnetizations Properties of Ferrimagnetic Model on Decorated Hexagonal Nanolattice: Monte Carlo Study

The ground states phase diagrams and magnetizations properties of ferrimagnetic model on decorated hexagonal nanolattice have been studied via Monte Carlo simulations. The shape of the phase diagrams depends of the values of the magnetic parameters given in the Hamiltonian. The phase diagrams show some key features: coexistence between regions, points where two, three, four and five and states can coexist. This richness of the ground state phase diagrams can serve as a guide for exploring interesting regions of the model’s finite temperature phase diagrams. The transition temperatures have been deduced for different values of exchange interactions between the atoms of spins moments(S). The effect of crystal field and exchange interactions on magnetization has been investigated. The magnetic coercive field and remanent magnetization are obtained for different parameters such as: exchange couplings and temperatures values. The superparamagnetic behavior has been found at the transition temperature.

Magnetic properties of binary axb1−x hexagonal monolayers: a Monte Carlo study

ABSTRACTThe magnetic properties of binary Ax(S = 3/2)B1−x(σ=2) hexagonal monolayers (A and B are the magnetic ions with spins S and σ, respectively) are studied via Monte Carlo simulations. The partial, total magnetizations and magnetic susceptibilities of binary Ax(S)B1−x(σ) hexagonal monolayers have been found for one proportion of spin-σ (x = 0.3). Magnetic phase diagrams of spin-σ (tC−x) of our system were deduced. The effect of crystal field on the total magnetizations has been studied for different proportions of spin-σ and for different values of exchange interactions between half-integer spins. The coercive field and remanent magnetization have been established for different proportions, x, exchange interactions R, exchange interactions between spins(σ–σ) and temperatures values.

Magnetic properties of mixed spin-5/2 and spin-2 Ising model on a decorated square lattice: A Monte Carlo simulation

The magnetic properties of mixed spin-5/2 and spin-2 Ising model on a decorated square lattice are studied using the Monte Carlo simulations. The ground state phase diagrams of mixed spin-5/2 and spin-2 Ising model on a decorated square lattice are obtained. The reduced transition temperature is obtained for different values of exchange interactions between mixed spins-5/2 and 2. The effect of reduced crystal field on the system are studied. The magnetic hysteresis cycles of the mixed spin-5/2 and spin-2 Ising model on a decorated square lattice for a several values of exchange interactions and reduced crystal field values have been found. Finally, the system exhibit the superparamagnetism behavior for d=-4 and for this value the total magnetization is equal to zero.

Magnetic properties of the Ising system on alternate layers of a hexagonal lattice

The magnetic properties of the mixed spin-1 and spin-5/2 Ising ferrimagnetic model on a hexagonal lattice have been studied using the Monte Carlo simulations. The hexagonal lattice study is formed by alternate layers of spins σ=1 and S=5∕2. The thermal variations of the magnetizations are given. The magnetic hysteresis cycles are established for different values of exchange interactions, crystal-field and temperatures. The magnetic coercive field is deduced.

Magnetocaloric effect and magnetic properties in YMnO3 perovskite

ABSTRACTThe magnetic properties and magnetocaloric effect in YMnO3 have been investigated using Monte Carlo simulations. The thermal magnetization, specific heat and magnetic entropy have been obtained for different values of exchange interactions and for a several external magnetic field values. The variation of adiabatic temperature change with the temperatures has been obtained for several values of external magnetic field. It has been found that the sample exhibited a paramagnetic to ferromagnetic phase transition at 30 K. The transition temperature of YMnO3 has been deduced for different values of size (1/L) and different values of exchange interactions. The relative cooling power with several values of external magnetic field has been established.

Dynamic Magnetic Features of the Mixed Ising System on the Bilayer Square Lattice

In order to study the dynamic magnetic features of the mixed spin-1 and spin-5/2 Ising system, we have used the mean-field theory (MFT) based on the Glauber-type stochastic dynamics on the bilayer square lattice (BSL). By employing the Master equation, dynamic equations describing the behavior of the system are derived. The average order parameters and dynamic order parameters are studied for different values of exchange interactions, oscillating magnetic field, and temperature. The complete dynamic phase diagrams (DPDs) are obtained for the ferromagnetic/ferromagnetic (FM/FM), ferromagnetic/antiferromagnetic (FM/AFM), and antiferromagnetic/antiferromagnetic (AFM/AFM) interactions in the different planes, and the role of the interaction in the Hamiltonian on the DPDs is explored. It is found that the DPDs display richer dynamic behavior for this mixed Ising system.

Size effect in graphene nano-islands: A Monte Carlo study

We study the magnetic properties of nanometer-sized graphene structures with of triangular graphene nano-islands using Monte Carlo simulation (MC). The transition temperature of graphene nano-islands formed by two triangular interpenetrating sublattices, Co and Fe, is determined with different values of exchange interactions $${ J}_{\mathrm{CoCo}}$$ , $${ J}_{\mathrm{FeFe}}$$ , $${ J}_{\mathrm{FeCo}}$$ and different layers for a zero magnetic field and a zero crystal field. The magnetic hysteresis cycles system formed by Co and Fe nano-islands have been established for different values of exchange interactions ( $${ J}_{\mathrm{CoCo}}$$ , $${ J}_{\mathrm{FeCo}}$$ ), for different values of temperatures and for different sizes of system. The emergence of magnetism in graphene nano-islands with well-defined zigzag edges has been studied using MC with different sizes. These nano-magnets show remanence and hysteresis because of magnetic anisotropy, which originates in the spin–orbit interaction, very small in graphene. These results can provide some guidance to structure design in the nano-islands. The superparamagnetic phase is also obtained in this system at the transition temperature.

Magnetic properties of the mixed spin-1 and spin-3/2 Ising system on a bilayer square lattice: A Monte Carlo study

The magnetic behavior of the mixed spin-1 and spin-3/2 Ising system on a bilayer square lattice is studied using the Monte Carlo simulations for both ferromagnetic/ferromagnetic and antiferromagnetic/ferromagnetic interactions in the presence and absence of external magnetic, crystal field and for different values of exchange interactions. The thermal variations of the magnetizations are given. The magnetic hysteresis cycles are established. The magnetic coercive field and the remanent magnetization are deduced. The coercive magnetic field, remanent magnetization and the transition temperature were not affect by the size effect.

Magnetocaloric effect in NdSi compound: a Monte Carlo simulation

Magnetic properties and magnetocaloric effects of the compound NdSi are studied by means of Monte Carlo simulations. NdSi can be considered as a competitive candidate of magnetic refrigeration. The thermal magnetization, dM/dT, magnetic entropy, and the specific heat of NdSi are given for different values of magnetic field and exchange interactions with a fixed crystal field. The magnetic entropy changes and those of the adiabatic temperature for different values of magnetic field and exchange interactions with a fixed crystal field are given. The reduced transition temperature of compound NdSi is obtained. The relative cooling power of NdSi has been obtained for different values of exchanges interactions and magnetic field. The magnetic hysteresis cycles of NdSi are obtained for different values of exchanges interactions and different values of reduced temperatures. With the merits of the large [InlineEquation not available: see fulltext.] and without hysteresis loss, NdSi can be considered as a competitive candidate of magnetic refrigeration in the low-temperature range.

Magnetic Behavior in Ising Nanoisland: a Monte Carlo Study

The magnetic properties of Ising nanoisland with a ferrimagnetic spin-1 and 3/2 configuration are studied by Monte Carlo simulation. The ground state phase diagrams of mixed spins are obtained. The critical temperature is obtained for different values of exchange interactions and for different crystal fields. The magnetic hysteresis cycle is obtained with different values of temperature, exchange interactions, and crystal field values. The applications of the Monte Carlo to the magnetic properties are extremely restricted for nanoislands, when the value of an interlayer coupling takes a large value, in contrast to a number of bulk studies.

Ferrimagnetic Behaviors in a Double-Wall Cubic Metal Nanotube: a Monte Carlo Study

The magnetic properties of double-wall cubic metal nanotube formed by ferrimagnetic spin-3/2 and 1 configuration are investigated by Monte Carlo simulation. The critical temperature is obtained for different values of exchange interactions. The total magnetization has been determined for different values of exchange interactions, different crystal fields, and different values of temperatures. The magnetic hysteresis cycle is deduced for different exchange interactions and for different temperatures.

Magnetic Properties of Graphene Structure: a Monte Carlo Simulation

The Monte Carlo simulation is used to study the magnetic properties of graphene structure formed by ferrimagnetic spin 5/2 and 3/2 configuration. The critical temperature is obtained for different values of exchange interactions and for different crystal fields. The total magnetization has been determinate for different values of exchange interactions, different crystal fields, and different values of temperature. The magnetic hysteresis cycle is obtained for different values of temperature, for different values of exchange interactions, and for different values of crystal fields. Graphene-based magnetoresistance sensors hold immense promise over existing sensors due to their stable performance over temperature variation, eliminating the necessity for expensive wafers or temperature correction circuitry. The potential applications for magnetic graphene would stretch broadly from information processing to medicine.

Monte Carlo simulation study of magnetic properties of Fe-doped Li3V2(PO4)3

The Fe-doped Li3V2(PO4)3 cathode materials for Li-ion batteries are studied by using the Monte Carlo simulations. The thermal magnetizations and magnetic susceptibilities of Li3V2(1−x)Fe2x(PO4)3 are studied for different values of exchange interactions with different dilutions x. The critical and Neel temperatures have been obtained for different dilution x. The magnetic hysteresis cycle is obtained for different dilution x and for different values of exchange interactions between V-Fe in plane and inter-plane. We have also studied the coercive field (hC) as a function of dilution x, crystal field, exchange interactions and temperature. It is observed that hC decreases with increasing dilution x as predicted theoretically.

Critical phenomena in Ising-type thin films by Monte Carlo study

The magnetic properties of ferrimagnetic spin-2 and 3/2 Ising-typed thin films are studied by Monte Carlo simulation. The critical temperature is obtained for different values of thickness of the thin film and for different exchange interactions. The total magnetization has been determined for different values of exchange interactions in surface and in bulk and different temperatures. The magnetic hysteresis cycle is obtained for different values of exchange interactions ferro and antiferromagnetic in the surface and in the bulk and for different values of temperatures for a fixed size of the film thickness. The coercive field increase with increasing the film thickness.

Magnetic Properties of Ferromagnetic and Antiferromagnetic Spins (1/2,1/2,1/2) Ising Model: a Monte Carlo Simulation

The magnetic properties of ferromagnetic and antiferromagnetic spins (1/2,1/2,1/2) Ising model are investigated by Monte Carlo simulation. The critical temperature is obtained for different values of exchange interactions. The total magnetization has been determinated for different values of exchange interactions and for different values of external magnetic field. The magnetic hysteresis cycle is obtained for different values of temperature and for different values of exchange interactions.

Thermal entanglement of the Ising–Heisenberg diamond chain with Dzyaloshinskii–Moriya interaction**Project supported by the National Natural Science Foundation of China (Grant No. 11274102), the New Century Excellent Talents in University of Ministry of Education of China (Grant No. NCET-11-0960), and the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20134208110001).

We investigate the thermal entanglement in a spin-1/2 Ising–Heisenberg diamond chain, in which the vertical Heisenberg spin dimers alternate with single Ising spins. Due to the fact that the Dzyaloshinskii–Moriya (DM) interaction contributes to unusual and interesting magnetic properties in actual materials, and moreover it plays a significant role in the degree of the entanglement of the Heisenberg quantum spin systems, we focus on the effects of different DM interactions, including Dz and Dx, on the thermal entanglement of the Heisenberg spin dimer. The concurrence, as a measure of spin dimer entanglement, is calculated for different values of exchange interactions, DM interaction, external magnetic field, and temperature. It is found that the critical temperature and the critical magnetic field corresponding to the vanishing of entanglement increase with DM interaction, and the entanglement revival region gets larger by increasing DM interaction, thus DM interaction favors the formation of the thermal entanglement. It is observed that different DM interaction parameters (Dz and Dx) have remarkably different influences on the entanglement. Different from the case Dz, there is the non-monotonic variation of the concurrence with temperature in the case Dx, and additionally the DM interaction Dx can induce the entanglement near zero temperature in the case that the antiferromagnetic Ising-type interaction constant is larger than the antiferromagnetic Heisenberg interaction constant. It is also shown that for the same value of DM interaction the critical magnetic field of the case Dx is larger than that of the case Dz.

Monte Carlo study of alternate mixed spin-5/2 and spin-2 Ising ferrimagnetic system on the Bethe lattice

The magnetic properties of alternate mixed spin-5/2 and spin-2 Ising model on the Bethe lattice have been studied by using the Monte Carlo simulations. The ground state phase diagrams of alternate mixed spin-5/2 and spin-2 Ising model on the Bethe lattice has been obtained. The thermal total magnetization and magnetization of spins-5/2 and spin-2 with the different exchange interactions, external magnetic field and temperatures have been studied. The critical temperature have been deduced. The magnetic hysteresis cycle on the Bethe lattice has been deduced for different values of exchange interactions, for different values of crystal field and for different sizes. The magnetic coercive field has been deduced.

Monte Carlo Simulation Study of Magnetic Properties of Li 3 V 2(PO4)3

The magnetic properties of Li3V2(PO4)3 in the presence of a dependent magnetic field, exchange interactions, and crystal field are studied by using the Monte Carlo simulations. The thermal magnetizations and magnetic susceptibilities of Li3V2(PO4)3 are given with different values of exchange interactions, crystal field, and external magnetic field. The critical exponent associated with the magnetization and with magnetic susceptibilities is given for different values of exchange interactions, crystal field, and magnetic external field. The magnetic hysteresis cycle with the reduced temperatures, the exchange interactions, and the crystal field is established.

Ferromagnetic and antiferromagnetic order analysis of Fe- and FeO-modified Graphene-nano-ribbon: A Monte Carlo simulation study

The magnetic properties of Fe- and FeO-modified Graphene-nano-ribbon: C32H2Fe2 and C32H2Fe2O2 are studied using Monte Carlo simulations. The thermal magnetization and magnetic susceptibility with different values of exchange interactions, zero crystal field and zero magnetic field are established. The transition temperature is deduced for different values of exchange interactions. The internal energy, magnetization with a fixed value of exchange interactions, zero crystal field and external magnetic field are given. The magnetization versus the exchange interaction with different values of temperature, different values of crystal field and external magnetic field of are obtained. The magnetic hysteresis cycles have been deduced.

Monte Carlo simulation of magnetic properties of a mixed spin-1 and spin-3/2 ferrimagnetic Ising system

Monte Carlo simulation has been used to study the magnetic properties of a mixed spin-1 and spin-3/2 ferrimagnetic through Ising model on a honeycomb lattice. The total magnetization, magnetization of sublattice A with spin 1 and sublattice B with spin 3/2 are studied for different values of exchange interactions, for a zero crystal field and for different values of a magnetic field. The total magnetization versus the exchange interactions JAB/JAA for different values of crystal field of two sublattices is given. Magnetic hysteresis cycles of system and sublattices are given for different values of exchange interactions and crystal field.