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Based on Monte Carlo simulation, the magnetic properties of a mixed spin-1 and spin-3/2 Ising superlattice with alternate layers are studied. The effects of interlayer coupling and external magnetic field on the compensation behavior and hysteresis properties for the ferrimagnetic superlattice are investigated. The occurrence of a compensation point is found to be greatly affected by the interlayer coupling. In particular, various multiple hysteresis loops can be observed under certain system parameters. The calculated results agree well with available experimental and theoretical works. [ABSTRACT FROM AUTHOR]

Based on Monte Carlo simulation, a model consisting of an antiferromagnetic (AFM) film coupled to a ferromagnetic (FM) film is developed to study the exchange bias and coercivity phenomenon. It is suggested that exchange bias is a consequence of exchange coupling in the AFM/FM interface, and the AFM anisotropy needs to have a threshold value for the occurrence of exchange bias. Simultaneously, exchange bias and coercivity as functions of the value of anisotropy, exchange coupling and film thickness are studied. By inducing a thickness dependence of the anisotropy in FM film, the coercivity can be reduced or enhanced by choosing suitable magnetic parameters, which can better account for the discrepancies found in previous studies. The results also provide evidence for the absence of a direct correlation between coercivity and exchange bias, which is in agreement with other studies. [ABSTRACT FROM AUTHOR]

Abstract: Based on Monte Carlo simulation, the magnetic properties of the ferrimagnetic nanoparticles on a body-centered-cubic lattice are investigated. The particle is described by a mixed-spin Heisenberg model in which S=3/2 and σ=1 are distributed in the two interpenetrating square sublattices. It is found that no compensation point occurs at finite temperature when only the nearest-neighbor interaction between S–σ spins is included. But, when the next-nearest-neighbor interaction between σ–σ spins is taken into account and exceeds a threshold value that depends on the other parameters such as the next-nearest-neighbor interaction between S–S spins and single-ion anisotropies in the Hamiltonian, a compensation point can appear. With the appropriate order parameter which is constructed to characterize the compensation behavior clearly, a variety of phase diagrams including the finite-size effect are derived and discussed. [Copyright &y& Elsevier]

Abstract: Based on Monte Carlo (MC) simulation, the magnetization behavior of one-dimensional mixed ferrimagnetic spin chain with complex arrangement and single-ion anisotropy under external field are investigated. It is assumed that the element of the mixed spin chain is composed of parallel spins with and parallel spins with . The simulated results indicate that l magnetization plateaus appear at the ground state as the external field increases from zero to its saturation value. In the mean time, it is found that is the integer part of . For different anisotropy value , there exist the degenerate states where the magnetizations are same while the corresponding spin configurations are different. Moreover, the calculated results in terms of the simple calculation of energy are associated with those simulated by MC method. [Copyright &y& Elsevier]

Abstract: Based on Monte Carlo simulation, the magnetic properties of the Heisenberg face-centered cubic (fcc) multilayer films with competitive nearest neighbor (NN) and next-nearest neighbor (NNN) interactions are investigated. Four different kinds of magnetic phases and spin orderings depending on the relative signs and strengths of NN and NNN interactions are presented and discussed. A new 4×4 transfer matrix method which is used to calculate the phase transition of films with NN and NNN interactions is derived. In addition, different order parameters are constructed to characterize the transition in different systems, and a complete description of phase diagram displaying transitions between those various phases is also reported. Finally, it is found that the simulated results are consistent with those derived by 4×4 transfer matrix method. [Copyright &y& Elsevier]

Abstract: An improved 4×4 transfer matrix (TM) method is developed. Based on Monte Carlo (MC) simulation and TM method, the effects of nearest- and next-nearest neighbor (NN, NNN) interactions on the magnetic properties of films with body-centered cubic structure are studied. The phase diagrams describing the phase transition temperature of the surface and inner layers are derived and the surface and size effects are also investigated. The simulated results by Monte Carlo method are in good agreement with those derived by mean field theory with the 4×4 transfer matrix, and can well explain the experimental facts. [Copyright &y& Elsevier]