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By using the effective field theory (EFT), the mixed spin-1/2 and spin-3/2 Ising ferrimagnetic model adapted to a double perovskite structure has been studied. The EFT calculations have been carried out from Ising Hamiltonian by taking into account first and second nearest-neighbors interactions and the crystal and external magnetic fields. Both first- and second-order phase transitions have been found in phase diagrams of interest. Depending on crystal-field values, the thermodynamic behavior of total magnetization indicated the compensation phenomenon existence. The hysteresis behaviors are studied by investigating the reduced magnetic field dependence of total magnetization and a series of hysteresis loops are shown for different reduced temperatures around the critical one. [ABSTRACT FROM AUTHOR]

Using Monte Carlo simulations, magnetic properties of the ferromagnetic nanoparticles of Ising spin-1 are investigated in the framework of the Ising model. The system is considered to have a Rubik’s cube structure composed of nanocubes having an equivalent exchange coupling, while, between adjacent nanocubes, the exchange coupling is assumed to vary. Both size effects and system parameters’ influence on phase diagrams of the nanosystem are studied. Thus, the magnetic properties of the system such as the critical temperature, the magnetization, and the coercive field are computed. [ABSTRACT FROM AUTHOR]

The main objective of this paper is to evaluate the physical properties of Fe 3 S 4 material. To do so, Ab-initio calculations and Monte Carlo Simulations (MCS) by means of the mixed spin model have been used. Fe 3 S 4 compound is formed by two magnetic sub-lattices, one occupied the A tetrahedral with spin 5/2 and the other occupied by B octahedral with both spin 2 and 5/2. The density of states (DOS) has been investigated and confirmed that the compoundis a half metal. Further, the magnetization, susceptibility and specific heat curves have been determined for different sizes of the systemand fromwhich the values of critical exponentsand the critical temperature (T c) have been calculated. Besides, the temperature-dependent magnetization for different values of crystal field has been analyzed to provide an insight into the relation compensation phenomena and crystal field effect. [ABSTRACT FROM AUTHOR]

We aim in this research paper to investigate and determine the magnetic properties of the simple perovskite PbVO by determining all the stable phases and analyzing and discussing the ground phase diagrams as a first step. As the second one, we established the magnetic properties of the studied compound employing a Monte Carlo simulation method within the framework of the Ising model to further the investigation. As a result of the employment of MCS, we succeed to determine the critical temperature, which is deduced by studying the magnetization, the susceptibility, and the specific heat. Then, comparing the previous experimental results with our theoretical obtained results, we found a good agreement between them. Also, the coupling effect on the transition temperature was shown. Finally, we analyzed the critical behaviors. [ABSTRACT FROM AUTHOR]

Using Monte Carlo simulations, we studied phase diagrams and magnetic properties of a ferromagnetic/antiferromagnetic Ising nanoparticles assembly with the spin-1/2 core and spin-3/2 shell. The system consists of nanocubes with equivalent exchange couplings of core and shell. However, the exchange couplings between the adjacent spins of the core and shell and between the nanocubes are assumed to vary. Thus, the effects of the exchange couplings and the system size on the phase diagrams are analyzing. Interesting behaviors are found when investigating the critical behavior of the system, the magnetizations, the magnetic susceptibility and the hysteresis loops. The increase of the core/shell size involves that of the temperature one. In addition, the increase in positive exchange interactions between the spins of the core and shell, on the one hand, and between the nanocubes, on the other hand, also increase the critical temperature, which favors the stable phase (3/2, 1/2). • Monte Carlo Simulation is used to study the magnetic properties of an assembly of cubic Core-Shell nanoparticles. • Phases diagrams of critical temperature with the exchange interactions and anisotropy parameter have been studied. • The increase of positive J2/J1 and J4/J1 increase the critical temperature, favoring the stable phase (3/2, 1/2). • Core and Shell sizes, anisotropy and interactions parameters effects on Magnetic hysteresis cycles are given. • Dependent coercivity with sizes and parameters of interactions are found. [ABSTRACT FROM AUTHOR]

In this paper, the electronic, structural, and magnetic properties of transition metal (TM) (V, Cr, Mn, Fe, Co, Ni, Cu)-doped CdSe are investigated using first-principles calculations within the density functional theory (DFT) and the local density approximation (LDA) in connection with the Korringa-Kohn-Rostoker coherent potential approximation (KKR-CPA) implemented in the AKAI MACHIKANEAMA code. The 3 d level locations of majority spin of those magnetic ions are studied. The spin-spin interaction at low concentration between magnetic impurities leads to ferromagnetic behavior. While the increase of TM concentration beyond 10 % leads to antiferromagnetic interactions between the magnetic ions, which suppress the ferromagnetism. Magnetic stability and Curie temperature are also calculated for different TM doping. And finally, two TMs are chosen to make a codoping in CdSe semiconductor material. [ABSTRACT FROM AUTHOR]