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This study presents an in-depth investigation into the physical properties of X2H3I (X = Ca or Sr) compounds, using density functional theory (DFT) as implemented in the Wien2k package. The analysis spans a range of properties, including structural, electronic, optical, and thermoelectric characteristics. The electronic structure calculations reveal that both compounds are non-magnetic semiconductors, with band gaps of 2.815 eV for Ca2H3I and 3.613 eV for Sr2H3I. The optical properties were also explored, with a focus on the absorption coefficient, where a notable peak was identified predominantly in the infrared region. For Sr2H3I, the highest absorption intensity was observed in the zz direction, whereas for Ca2H3I, significant absorption was noted in the xx and yy directions. Additionally, the Seebeck coefficient was studied as a function of temperature, showing an increasing trend, indicating that these materials have a higher potential to generate electrical voltage under a temperature gradient, making them promising candidates for thermoelectric applications. Moreover, the hydrogen storage potential was evaluated, with gravimetric capacities of approximately 1.419 wt% for Ca2H3I and 0.981 wt% for Sr2H3I. [ABSTRACT FROM AUTHOR]

Context: Nowadays, Perovskite materials with diverse compositions and structures have garnered significant attention for their potential applications across various industrial and technological fields. Here, we investigated the structural, electronic, optical, thermodynamic, thermoelectric, and magnetic properties of perovskite PrFeO3 using density functional theory and Monte Carlo simulations. The optimization results demonstrate that the ferromagnetic phase is more stable than the antiferromagnetic phase. Under the GGA + SOC + U and GGA + mBJ approaches, the electronic results of the PrFeO3 compound expose the half-metallic and magnetic behavior. It was also demonstrated that introducing dilatation strain can effectively enhance both the mechanical and thermal stability of PrFeO3. Additionally, the optical properties show that this material has potential uses for solar cells because of its capacity to absorb light in the ultraviolet (UV) spectrum. The maximum values of the Seebeck coefficient reach 90 µV/K at 1000 K, indicating the potential of PrFeO3 as an efficient thermoelectric material. The magnetic properties exhibit a first transition of spin reorientation (TSR) at 171.44 K, followed by a second-order transition at 707.15 K. This investigation provides valuable insights into the unstudied aspect of Perovskite PrFeO₃. Methods: To carry out this investigation, we employed the density functional theory (DFT) implemented in the Wien2k package. To determine the exchange–correlation potential, we utilized the GGA-PBE (Perdew, Burke, and Ernzerhof) approach. The SOC was included based on the second-variational method using scalar relativistic wavefunctions, and electron–electron Coulomb interactions for Fe and Pr are considered in the rotationally invariant way GGA + SOC + U. In this paper, the effective parameter Ueff = U − J was adopted, where U and J stand for the Coulomb and exchange parameters, respectively. Also, we opted for the modified Becke–Johnson potential (mBJ) for comparison. The thermodynamic properties are obtained using the quasi-harmonic Debye model via Gibbs2 software programs. For the calculation of thermoelectric coefficients, a combination of first-principles band structure calculations and the Boltzmann transport theory within the rigid band approximation (RBA) and the constant scattering time approximation (CSTA) was employed, utilizing the BoltzTrap code. Subsequently, we delve into the magneto-caloric and magnetic properties by employing Monte Carlo simulations. [ABSTRACT FROM AUTHOR]

This work comprehensively studies the electronic, structural, optical, thermodynamic and thermoelectric properties of the Co2CrBi Heusler compound for both ferromagnetic and antiferromagnetic phases. The calculation is based on the Full-potential Linearized Augmented Plane-Wave (FP-LAPW) method by using the "WIEN2k" code, with the Generalized Gradient Approximation (PBE-GGA) for the exchange–correlation potential. The calculations reveal that Co2CrBi exhibits metallic behavior due to the spin polarization at the Fermi level. Further calculations were performed using GGA + SOC + U and hybrid functional HSE06 approximations to confirm this metallic nature. The antiferromagnetic phase is more stable than the ferromagnetic phase, although it cannot be regarded as a hard material. Various properties, including electron energy loss, refractive index, extinction coefficient, optical conductivity, Seebeck coefficient, electrical conductivity, and thermal conductivity are also computed and discussed for both ferromagnetic and antiferromagnetic phases. Additionally, this investigation is extended to encompass the unexplored properties of Co2CrBi, including both thermodynamic and thermoelectric. [ABSTRACT FROM AUTHOR]

In this work, we used Monte Carlo simulations to illustrate the magnetic properties of the structure of fullerene C36 formed with the mixed spins 3/2 and 1. We applied the reduced crystal field, the reduced external magnetic field, and the different reduced coupling interactions between the mixed spins of the studied system. In the absence of any temperature fluctuations, the ground-state phase diagrams have been established and discussed in different planes formed with the external magnetic field, the coupling interactions between spins and the reduced crystal field. In addition, the impact of rising reduced temperature on the magnetizations and the derivative of magnetization has been shown. It is found that, at specific reduced temperature values, the system could change from the ferromagnetic to the paramagnetic phase. Also, the variation of the reduced exchange coupling interactions leads to increasing values of the magnetic reduced coercive field, shown by the hysteresis loops. The C36 structure with mixed spin S and σ. [ABSTRACT FROM AUTHOR]

Perovskites represent distinctive materials suitable for both transport and optoelectronic applications, harnessing renewable resources to produce energy. In this study, the perovskite Li2SnI6 has been explored, focusing on a comprehensive analysis of its physical properties under strain. The encompassed investigation of the structural, elastic, electronic, optical, and thermoelectric characteristics of the studied compound. Utilizing density functional theory (DFT) implemented in the Wien2k package, we employed the LSDA+mBJ approximation to determine the exchange-correlation potential. The elastic constants and related parameters have been reported such as bulk modulus, shear modulus, Young's modulus, anisotropy factor, Poisson's ratio, and internal strain parameter for Li2SnI6 in its cubic structure. The electronic part reveals the semiconductor behavior of the studied compound and a decrease in gap energy with increasing pressure, reaching Eg = 0.2 eV for P = 12 GPa. Additionally, the absorption of optical factors lies in the ultra-violet (UV) region, noted at P = 12 GPa, with an intensity of 230 × 104 cm−1, which makes this material suitable for photovoltaic devices. Furthermore, we delved into the electrical conductivity, Seebeck coefficient, and electronic part of thermal conductivity. The results indicated that the compound demonstrates p-type behavior, as evidenced by positive values for the Seebeck coefficient with the highest value of 240 µV/K observed for P = 4 GPa. The analysis of thermoelectric and optical properties suggests that the studied perovskite is well-suited for applications in renewable energy. [ABSTRACT FROM AUTHOR]

In this study, our primary objective is to examine the effect of strain on the HfO2 compound, delving into its diverse array of physical attributes. Our investigation encompassed an exploration of its structural, electronic, optical, thermodynamic, and thermoelectric characteristics, both under tensile and compressive strain conditions. To undertake this research, we used the density functional theory (DFT) as implemented in the Wien2k software package. To pinpoint the exchange-correlation potential, we adopted the GGA-PBE (Perdew, Burke, and Ernzerhof) method. Our findings unequivocally establish that the HfO2 compound behaves as an insulator. Furthermore, we meticulously evaluated a wide spectrum of optical properties, encompassing electron energy loss, absorption coefficient, as well as the real and imaginary components of the dielectric tensors and optical conductivity. Additionally, we computed the Debye temperature and the Grüneisen parameter. In tandem with these investigations, we probed the electrical conductivity, Seebeck coefficient, and electronic conductivity. Notably, our results unveiled that the compound demonstrates p-type behavior, characterized by positive values for the Seebeck coefficient. These outcomes could be useful for the properties of the studied HfO2 compound. [ABSTRACT FROM AUTHOR]

Context: As new materials, the ternary chalcogenides have recently brought scientists' attention. These materials are a novel class of semiconducting chemical compounds. They allow the increase of the photo-conversion efficiency, the performance, and the cheap energy cost. Such materials also provide a wide range of physical and chemical applications. Methods: The used investigation employs Density Functional Theory (DFT) implemented in the Wien2k package to systematically characterize the physical properties of ternary chalcogenide compounds XBiSe2 (X = Li, Na and K). Such method emphasizes their applicability to energy conversion technologies. Scrutinizing their electronic, optical, and thermoelectric properties elucidates the effect of alkali metal substitution on performance metrics. The results not only advance knowledge of these materials' physicochemical behaviors but also reveal their potential for tailored functionalization in next-generation energy and optoelectronic systems, marking a significant stride in material science and application-oriented research. [ABSTRACT FROM AUTHOR]

First-principles calculations and Monte Carlo simulations were employed to examine the properties of the MnCoBi Half-Heusler alloy across various domains, including its structural, electronic, optical, thermodynamic, magnetic and magnetocaloric characteristics. The structural analysis unveiled the stability of MnCoBi in a ferromagnetic state. Regarding electronic and magnetic attributes, the calculations demonstrated that MnCoBi exhibits a half-metallic nature, featuring an indirect band gap of 0.487 eV spin down when employing GGA + U + SOC. Furthermore, the evaluation of elastic properties indicated that the formation of the MnCoBi compound is indeed elastically stable. The optical properties, encompassing the dielectric function, optical conductivity, refractive index, absorption coefficient, reflectivity, and electron energy loss, were also computed and the results were thoroughly examined. Additionally, the thermodynamic properties of the MnCoBi compound were explored using the Debye quasi-harmonic model. The investigation delved into the magnetic behavior of the system as a function of temperature. Finally, the study presented magnetocaloric properties and delved into the hysteresis cycles concerning external magnetic field variations. [ABSTRACT FROM AUTHOR]

This study presents a thorough theoretical investigation into the intrinsic properties of Sr2RuO4 material that has garnered significant attention due to its half-metallic nature. Utilizing advanced Density Functional Theory (DFT) simulations, the examination of the electronic, optical, and thermoelectric properties provides insights into the fundamental behaviors of Sr2RuO4. The DFT simulations reveal critical aspects of its electronic structure, which supports the material's potential application in spintronic devices. Additionally, the optical properties are analyzed. The study extends to evaluating the thermoelectric performance, suggesting avenues for energy conversion efficiency. To complement these analyses, the Gibbs2 method is employed to assess the thermodynamic stability and responses of Sr2RuO4, offering predictions on its thermal behavior under various conditions. The convergence of these theoretical predictions provides a foundational understanding of Sr2RuO4, paving the way for its application in future technologies. [ABSTRACT FROM AUTHOR]

In this work, we report on a comparative study of the structural, optical, and elastic properties of SrTiSe3 and SrZrSe3 compounds using the DFT method. The lattice constants of the compounds are calculated using the GGA-PBE approximation and the hybrid functional Heyd, Scuseria, and Ernzerhof (HSE). The properties of the SrTiSe3 and SrZrSe3 materials in relation to electronic composition, elastic constants, and optical characteristics are deduced and analyzed. Both compounds display magnetic behavior, according to electronic calculations. SrTiSe3 shows metallic behavior, as the calculated bandgap value is zero. SrZrSe3, on the other hand, has a bandgap of 0.347 eV, which demonstrates its semiconducting nature. We have demonstrated that the plasma frequency of SrTiSe3 is around 1.77836. Using density functional theory, we report on the electronic characteristics of the compounds under mechanical stress. For SrZrSe3, the gap energy values rise with compressive stress and decrease with increasing tensile stress to zero. In addition, the study includes the extinction coefficient, optical conductivity, dielectric tensor, electron energy loss, and refractive index. [ABSTRACT FROM AUTHOR]

The magnetic and magnetocaloric properties of a zigzag triangular nano-graphene with Ruderman-Kittel-Kasuya-Yosida (RKKY) exchange interactions in the mixed 1 and 3/2 spins are studied with the aid of the Monte Carlo investigations. The thermal magnetizations and the magnetic susceptibilities are considered. The phase diagram of the system and the variation of magnetizations with crystal field are established. The magnetic entropy for different external magnetic fields has been also sketched. The dependence of the field on the relative cooling power (RCP) of the system is found; the specific heat displacement of the system is displayed. Also, the adiabatic temperature of the system has been defined. Lastly, the magnetic hysteresis cycle with mixed spins S = 1 and σ = 3/2 for several different parameters is obtained. It can be observed that the values obtained for RCP rise with increasing external magnetic field and reduce with increasing N for constant parameters. The critical temperature values are also affected by the increasing number of non-magnetic layers. In addition, the effect of the RKKY interaction decreases as 1/N2. As a consequence, the system becomes rapidly out of order as the number of non-magnetic layers N is increased. [ABSTRACT FROM AUTHOR]

In this study, we present a DFT approach to the tungsten chalcogenides WSe2 and WTe2 physical properties by using the "WIEN2k" package. The lattice constants of the studied compounds are calculated in the framework of the GGA-PBE approximation. In particular, we studied and discussed the magnetic properties of the WX2 compounds (X = Se and Te). We calculated and explained the band gap values, the elastic constants, and the electronic properties of these compounds. In addition, the dielectric tensor, the optical conductivity, the refractive index, and the absorption have been illustrated. On the other hand, the thermodynamic and thermoelectric properties of the tungsten chalcogenides WSe2 and WTe2 have been presented. We concluded that the WX2 (X = Se and Te) compounds exhibit semiconductor properties with the energy gap values 1.046 and 0.542 eV for WSe2 and WTe2, respectively. Additionally, the computed WTe2 and WSe2 parameters were compared to those found in the literature. Good deals have been discovered. [ABSTRACT FROM AUTHOR]

In this work, using the Monte Carlo study, we illustrated the magnetic and magnetocaloric properties of the L-graphdiyne system with mixed 5/2 and 3/2 spins. We obtain magnetizations and magnetic susceptibilities of the system. The Neel temperature and the reduced compensation temperature are determined. The magnetic entropy changes of L-graphdiyne for several reduced external magnetic fields and the number L of hexagons are displayed. The relative cooling power has been calculated and discussed. Magnetic hysteresis cycles for different L = 1, 2, 3, and T = 2 demonstrate that the magnetization saturation increases with increasing L. In addition, the reduced magnetic coercive field increases with decreasing reduced exchange interaction r. Furthermore, the reduced magnetic coercive field increases with increasing values of the exchange coupling interactions p. In particular, super-paramagnetic behavior has been found for L = 1, due to the low values of the reduced magnetic coercive field. [ABSTRACT FROM AUTHOR]

In this paper, we investigated the effect of vacant sites on the magnetic properties of the germanene nanostructure. The Blume-Capel model was utilized to investigate the nano-system with the spin-7/2. Moreover, we employed Monte Carlo simulations (MCS) with the Metropolis algorithm to explore how the presence of vacant sites influences the magnetic properties under varying parameters such as temperature, exchange coupling interaction, crystal field, and external magnetic fields. It has been found that the transition from the ferromagnetic phase to the superparamagnetic one takes place more quickly by increasing the value of the vacancy number (VN). Besides, increasing the parameter VN leads to a decrease in the remanent magnetization while the coercive field remains constant. These findings can improve the examined system for potential nanotechnology applications. [ABSTRACT FROM AUTHOR]

This paper explores the photovoltaic and thermoelectric properties of composites consisting of NaSnX3 (X = Br or I). The study uses density functional theory in conjunction with the Boltzmann Transport Theory. Initially, the structural, electronic, and optical properties of the materials are inspected using the generalized gradient approximation (GGA) based on the Perdew–Burke–Ernzerhof approximation (GGA-PBE) with consideration of the cross-correlation potential. The findings reveal that the studied compounds exhibit a p-type semiconductor character along with intriguing optical properties. Afterward, the thermoelectric properties of the materials are examined and discussed in the second part of the study. This analysis includes the Seebeck coefficient, electrical and thermal conductivities, the figure of merit, and the power factor. It is observed that the Seebeck coefficient demonstrates positive values, confirming the p-type semiconducting properties of the two materials under study. Additionally, these compounds exhibit significant values of the figure of merit (ZT) values when compared to existing thermoelectric materials. Especially, the large ZT values are achieved at both low and high-temperature ranges. Generally, these materials hold potential for applications in photovoltaic and/or thermoelectric fields. [ABSTRACT FROM AUTHOR]

In this paper, we report the magneto-caloric properties of the Graphdiyne structure with mixed 3/2 and 1 spins investigated by Monte Carlo simulations. Such calculations were performed under the Metropolis algorithm. We illustrate the magnetizations and dM/dT of the Graphdiyne system with these mixed spins. It is found that the magnetic entropy of the Graphdiyne changes when varying the temperature values for several values of the external magnetic field. The maximum magnetic entropy variations of the system are deduced. The relative cooling power (RCP) coefficient of the Graphdiyne system has been estimated for several values of the external magnetic field. To complete this work, we have illustrated the magnetic hysteresis cycles of the Graphdiyne for fixed values of the other physical parameters. [ABSTRACT FROM AUTHOR]

The magnetic properties of a ferrimagnetic-type bathroom-tile (4–8) core–shell nanostructure with the mixed spins (3/2, 7/2) are studied using Monte Carlo simulations. The aim of this paper is to study the impact of the core size on the magnetic properties of a core–shell nanosystem. We start by illustrating and discussing the ground-state phase diagrams in different physical parameter planes. Then, we study the thermal behavior of magnetizations and susceptibilities. Furthermore, we examine the core size effect on the compensation temperature. Finally, we discuss the variation of the total magnetization as a function of the crystal and external magnetic fields. [ABSTRACT FROM AUTHOR]

Monte Carlo study under the Metropolis algorithm is performed to investigate the ground state phase diagrams and hysteresis electric cycles by using the Blume–Emery–Griffiths (BEG) model with the mixed spins (S-1, σ-3/2). Firstly, the ground state phase diagram has been established to show the more stable configurations corresponding to the physical parameter EZ/JC. Moreover, the hysteresis electric cycle behaviors have been investigated by varying temperature, exchange coupling interactions, crystal field and biquadratic parameters of the carbon-like nanotube. It is found that the increase in the crystal field and the biquadratic exchange parameters decrease the surface of the loops leading to the apparition of the polarization plateaus. [ABSTRACT FROM AUTHOR]

In this work, we study the ground state phase diagrams and the magnetic properties of the mixed spins (S-1, σ-7/2) of the Hexacene-like nanostructure. In the first step, the ground state phase diagrams have been established to show the more stable configurations corresponding to different physical parameters. Besides, the Monte Carlo simulations are used to investigate the effects of the temperature, the exchange coupling interactions, the crystal field, and the external magnetic field on the magnetization. Moreover, the hysteresis cycle behaviors have been investigated. It is found that the studied system exhibits two compensation temperatures (Tcomp1; Tcomp2) which depend on the exchange coupling parameters and the external magnetic field. [ABSTRACT FROM AUTHOR]

Monte Carlo simulations at low temperature under the Metropolis algorithm have been used to investigate the behavior of the magnetization plateaus of the honeycomb nanolattice with mixed spins (σ-3/2 and S-5/2) by varying the crystal field (d), the exchange coupling interactions ( r 1 and r 2 ) and the dilution concentration (c). We examine the behavior of the magnetization plateaus for different physical parameters and we explore the critical (hC1, hC2, hC3) and the saturation (hS) magnetic fields. Furthermore, the studied honeycomb nanolattice shows four magnetization plateaus behaviors at low temperature. Besides, increasing the dilution concentration parameter is very important to find the new magnetization plateaus. [ABSTRACT FROM AUTHOR]

In this study, we use the Quantum Espresso code under the pseudo-potentials wave method based on density functional theory (DFT) to investigate the structural, electronic, and magnetic properties of the rare earth-based solar perovskites GdAlO3, DyAlO3, and HoAlO3 materials. In fact, the optimized unit cells for each one of these materials have been used to explore the stability and the ferromagnetic behavior of such materials. It is found that the cubic perovskite HoAlO3 material is the more stable structure, while the compound DyAlO3 is more stable than GdAlO3 alloy in this structure. On the other hand, the band structure and density of states confirm that the GdAlO3 perovskite has a semiconductor nature, while the DyAlO3 and HoAlO3 exhibit a half-metallic ferromagnetic character. In addition, the spin-polarized magnetic moments of these compounds reveal that these materials show a ferromagnetic nature. Moreover, the calculated magnetic moments of the cubic GdAlO3, DyAlO3, and HoAlO3 are 7.02 μB, 5.00 μB, and 4.00 μB, respectively. Furthermore, the obtained results approve that these compounds could be promising materials for spintronic and optoelectronic devices. Moreover, such materials are promising candidates for photovoltaic applications. [ABSTRACT FROM AUTHOR]

The paper discusses the dilution concentration effect on the magnetic properties of the three nano-Heusler Ru2MnX (X = Nb, Ta, V) compounds using the Blume–Capel Ising model. The studied nano-Heusler compounds are composed of a mixed atom spins. In this work, we use Monte Carlo simulations under the Metropolis algorithm. The diluted effects on the magnetic properties of the three nano-Heusler compounds have been explored. Antiferrimagnetic to superparamagnetic phase was well examined around the blocking temperature. Besides, the total magnetizations of each nano-Heusler compound behaviors as a function of the temperature and the external magnetic field by varying the dilution concentration have been investigated. [ABSTRACT FROM AUTHOR]

In this paper, we study the magnetic properties of a tri-layer graphyne-like structure using Blume-Capel Ising model. The studied system is composed by a mixed spins σ = ± 5/2, ± 3/2 and ± 1/2 (in the plane B) and S = ± 2, ± 1 and 0 (in the plane A). The study is performed through Monte Carlo simulations under the Metropolis algorithm. Besides, we examine the effects of the exchange coupling interactions on the obtained compensation temperature. Additionally, we investigate the effects of the crystal and external magnetic fields on the partial and total magnetizations. The magnetic and thermal properties of the considerate system are largely affected by the exchange coupling interactions, the crystal and external magnetic fields. [ABSTRACT FROM AUTHOR]

In this paper, we study and discuss the ab initio method and Monte Carlo simulations of the Fe2MnSn full Heusler alloy for the both structures: XA and L21. In fact, we have computed the structural, the electronic, the magnetic and the critical magnetic behavior of this alloy. Firstly, we have performed the ab initio calculations using the GGA approximations. The results of the electronic structures show that the full Heusler Fe2MnSn alloy shows a half-metallic character and a 100% spin polarization, only for the XA phase, at the Fermi level. This half-metallic behavior is confirmed by the integral value of the computed total magnetic moment value (6.00 μB). For non-null temperature values, we illustrate the magnetization behavior by using the Monte Carlo simulations (MCS) under the Metropolis algorithm. The magnetizations are illustrated and discussed as a function of the temperature and the exchange coupling interactions. To complete this study, we present and discuss the Monte Carlo results and compared them with the existing experimental values in the literature. [ABSTRACT FROM AUTHOR]

Our aim of this work is to study the magnetic properties of a bi-layer borophene structure, using Monte Carlo simulations under the Metropolis algorithm. Such a system is formed by two layers. The first one contains 126 atoms with spin σ = ± 3/2, ± 1/2 and 84 atoms with spins S = ± 1, 0 while the second one contains 84 atoms with spin σ = ± 3/2, ± 1/2 and 126 atoms with spins S = ± 1, 0. We establish, in various planes, the ground-state phase diagrams. Furthermore, we present the thermal variation of the total magnetization and total susceptibility for several values of exchange coupling interactions and crystal field. It is found that the increase in both exchange coupling interactions leads to an almost linear increase in transition temperature in one hand and, on the other hand, to a decrease in the corresponding crystal field transition. [ABSTRACT FROM AUTHOR]

The magnetic properties of antiferromagnetic Mn3ZnN anti-perovskite nanoparticles have been studied using Monte Carlo simulations within the Ising model. The considered Hamiltonian includes the exchange interactions between Mn–Mn and the external magnetic field. The thermal magnetizations and magnetic susceptibilities of Mn3ZnN anti-perovskite nanoparticles are computed for different sizes. The Néel temperature is deduced. The exchange interaction between Mn and Mn atoms is obtained. Beyond the coupling value 2 K, the magnetization of system becomes independent of effect temperature. In addition, the variation of magnetizations with external magnetic field and crystal filed are also established for different temperatures. Mn3ZnN anti-perovskite nanoparticles exhibits the superparamagnetic behaviour for different temperatures value. [ABSTRACT FROM AUTHOR]

In this paper, we have studied the magnetic properties of the nanotube core-shell structure with RKKY (Ruderman-Kittel-Kasuya-Yosida) interactions, using Monte Carlo simulations (MCS). The system consists of hexagonal core-shell nanotube structure with mixed spins σ = ± 3/2, ± 1/2 (of the core) and S = ±1, 0 (of the shell), separated by non-magnetic nanotubes. Initially, we start this study by discussing for zero temperature, the ground-state phase diagrams in different planes. Moreover, we investigate for the positive temperature values, the effect of the RKKY interactions on the thermal magnetization and magnetic susceptibility of the system. Additionally, we study the effects of the exchange coupling interactions of the core and of the shell on the compensation and transition temperatures. Finally, we explore the behavior of the magnetic hysteresis cycles as a function of the non-magnetic nanotubes number, the temperature, and the exchange coupling parameters. [ABSTRACT FROM AUTHOR]

In this study, we use Monte Carlo simulations (MCS) and DFT method in order to deduce the critical magnetic behavior of the rare earth-based alloy GdN. The Monte Carlo method is based on the Metropolis algorithm, while the DFT method is applied under the generalized gradient approximation. In a first step, we discuss and study the density of states, the exchange coupling interactions, the crystal field and the Curie temperature within the mean-field approximation. We started by studying the ground state phase diagrams in the different planes of the physical parameters. In fact, we present and discuss the behavior of total magnetizations and susceptibilities as a function of: the temperature, the crystal field, the exchange coupling interactions and the external magnetic field. To complete this study, the hysteresis loops are illustrated and analyzed when varying the external magnetic field for fixed specific values of the other physical parameters. The obtained values of the critical exponents of the GdN compound have been deduced and compared with those existing in the literature. [ABSTRACT FROM AUTHOR]

In this manuscript, we study the structural, electronic, and magnetic properties of the equiatomic quaternary Heusler alloy ZnCdRhMn in the framework of the first-principle calculations and Monte Carlo simulations. In fact, we have investigated the structural, the magnetic, and the electronic properties of the Zn-based equiatomic quaternary Heusler alloy ZnCdRhMn using the ab initio method in the bases on the GGA approximation. On the other hand, the critical behavior of the equiatomic quaternary Heusler alloy ZnCdRhMn has been outlined by the Monte Carlo simulations. For this end, we apply the Metropolis algorithm. The objective of this work is to improve the competition between the austenitic and martensitic phases on the existence of magnetic and electronic properties of this alloy. The half-metallic behavior is only improved for the austenitic structure and 100% of spin polarization has been found. Moreover, a high curie temperature is found for this alloy for the austenitic phase. We can conclude that the austenitic structure of this alloy is useful for the spintronic device applications. [ABSTRACT FROM AUTHOR]

The aim of this paper is to investigate the magnetic properties of the MnBi magnetic systems by using the Monte Carlo simulation. Indeed, we analyzed the effect of the number of layers on the magnetic properties of the compound MnBi. The magnetization, the binder cumulant, the Curie temperature, and the hysteresis cycle are also calculated in this work. We used the free boundary conditions to simulate the properties of the studied system, and we presented the effect of multilayer numbers on the magnetic properties of MnBi films. Indeed, the indications that coercive field increases drastically with the increases multilayer numbers is consistent with the experimental facts. [ABSTRACT FROM AUTHOR]

In this manuscript, we investigate the physical properties such as the magnetic and the electronic properties of the Co-based equiatomic quaternary Heusler alloy CoYCrZ (Z = Si and Ge). These investigations have been performed by employing the Quantum Espresso code in the framework of density functional theory (DFT). The generalized gradient approximation (GGA) of Perdew–Burke–Ernzerhof (PBE) is used for all these calculations. The band structures, and density of states calculations, show that all these materials CoYCrZ (Z = Si and Ge) exhibit a half-metallic (HM) behavior only for the structure type II. Moreover, this structure type II is found to be the most stable configuration for all these alloys. On the other hand, it has been found that the Slater–Pauling is well described for the compound CoYCrGe, only for the configuration type II. In particular, the equiatomic quaternary Heusler alloys CoYCrSi and CoYCrGe are found to be half-metallic for the structure type II. This is due to the fact that they have 100% spin polarization SP. Also, the existence of complete SP in the studied alloys is the reason for which these materials are useful for spintronic device applications. [ABSTRACT FROM AUTHOR]

In this work, using the ab-initio calculations, we have investigated the phantom magnetism when the diamagnetic solids, carbon and nitrogen with d 0 doped CdTe. We have applied in these calculations the combination between the Korringa–Kohn–Rostoker and coherent potential approximation method within the local density approximation and generalized gradient approximation (GGA). In this study, the doped compound presents a metallic behavior for both the approximations characterized by a small moment of about 0.299/0.326 and 0.249/0.266 μ B for 24% of C and N, respectively. The polarization has shown a low and decreasing value from 43.73/59.56 to 0.29/2.26% for 9% and 24% of C impurity concentration, respectively. Unlike for the case of N, this parameter varies from 76.7/72.86 to 85.29/83.63% for 9% and 24% concentration, respectively. In addition, we have determined the mechanism of ferromagnetic coupling for the C- and N-doped CdTe. Furthermore, the stability of the compound is investigated by comparing the energy difference between the spin glass and ferromagnetic states. It is found that below the percolation threshold, contrary to the case of doping by N except for 20% using GGA, the C impurities lead to the most ferromagnetic stable phase. While the system changes its stability above this threshold when doped by the C impurities. Finally, we have estimated and discussed the Curie temperature using the mean field approximation. [ABSTRACT FROM AUTHOR]

In this manuscript, structural, electronic, optical and thermoelectric properties of chloride perovskites LiMCl3 (M = Pb or Sn) have been studied using Density Functional Theory (DFT) implemented in ABINIT code. The exchange–correlation functionals is treated with Generalized Gradient Approximation of Perdew Burke Ernzerhof (GGA-PBE). Structural properties revealed that the equilibrium lattice parameters for LiPbCl3 and LiSnCl3 are 5.686 and 5.597 Å respectively. These values were used to investigate the thermodynamic stability of these materials by evaluating the energy of formation. The negative formation energy results suggest that the synthesis of LiPbCl3 and LiSnCl3 perovskites is feasible. Further, electronic properties revealed that LiMCl3 (M = Pb and Sn) perovskites are semiconductors with indirect band gaps of 1.87 and 0.98 eV for LiPbCl3 and LiSnCl3, respectively. From the optical properties, we found that the studied materials have a high absorption coefficient, greater than 104 cm−1 in the visible region, indicating their suitability as photovoltaic absorber materials. The results of the elastic properties show that both perovskites are stable and possess ductile behavior. In addition, thermoelectric properties of LiMCl3 (M = Pb and Sn) have been calculated and analyzed using the combination of electronic structure and Boltzmann transport theory. The thermoelectric efficiency results suggest that LiPbCl3 and LiSnCl3 could be potential candidates for thermoelectric devices for high-temperature applications. [ABSTRACT FROM AUTHOR]

The effects of single-ion anisotropies and an external magnetic field on the magnetization of the mixed-spin (7/2, 3/2) ferrimagnetic Ising system are investigated within Monte Carlo simulation. Under certain values of the physical parameters, multiple hysteresis loop behaviors such as double, triple, and quintuple hysteresis cycles have been observed. Particularly, the superparamagnetic phase has been shown. The ground-state phase diagrams are presented. [ABSTRACT FROM AUTHOR]

In this paper, we used the ab-initio calculations, based on the Korringa-Kohn-Rostoker (KKR) method combined with the coherent potential approximation (CPA), to simulate the magnetic properties of ZnO, doped and co-doped with manganese and carbon, respectively. For this purpose, we have used two different approximations: the Local Density Approximation (LDA) and the Local Density Approximation-Self-Interaction Correction (LDA-SIC). Numerical results are presented for the compound Zn1 − 0.06Mn0.06O1−xCx when doping and co-doping is performed with Mn and C as doping elements. Total and partial DOSs are given for different concentrations using the two approximations, LDA and LDA-SIC. It is found that for 6% with doping by Mn the system becomes magnetic. The co-doping with carbon changes the behavior of the system : it becomes also magnetic for 4, 6 and 10% concentrations within both, LDA and LDA-SIC approximations. Furthermore, we have discussed the type of mechanism of exchange interaction and found that the double exchange is responsible for the appearing magnetism in the system, within the LDA and p-d interaction for LDA-SIC approximation. For 10% of carbon, we have found that the critical temperature approaches 280 K in the LDA approximation solely; and is about 305 K in the LDA-SIC approximation. [ABSTRACT FROM AUTHOR]

The ferrimagnetic systems have been extensively investigated because of their fascinating properties. In this paper, the mixed spin-7/2 and spin-3 Ising system with periodic boundary conditions on a square lattice has been studied using the Monte Carlo simulation within the Metropolis algorithm; the Hamiltonian of the system includes the interaction between the first nearest neighbors and the crystal fields Δ7/2 and Δ3 generated by the spin-7/2 and spin-3, respectively. The ground-state phase diagram of the system has been established. On the other hand, the impact of the single-ion anisotropies on the compensation temperature has been shown. Several topologies of the total magnetization have been found for this system. [ABSTRACT FROM AUTHOR]

The double Perovskite Bi2FeCrO6 (BFCO), is a variant of the well-known and largely studied perovskite BiFeO3. These perovskites (BFCO) are theoretically and experimentally studied because of their strong ferro-electricity and high magnetic Curie temperature beyond the room temperature. This manuscript presents a theoretical model describing and predicting the double perovskite Bi2FeCrO6 material, in order to simulate its magnetic properties. For this purpose, we use the Monte Carlo method under the Metropolis algorithm. Also, we present the behavior of the magnetizations and the susceptibilities as a function of the temperature as well as different physical parameters, such as the coupling exchange interactions, the crystal field and the external magnetic field. On the other hand, we presented and discussed the ground state phase diagrams by exploring the different stable configurations in different planes of the physical parameters. To complete this study, we established the magnetic hysteresis loops of the double perovskite Bi2FeCrO6 compound, for different physical parameters. [ABSTRACT FROM AUTHOR]

In this paper, we aimed to study the effect of doping of the compound CdTe with the cobalt impurity (Co), as well as the vacancy defects in Cd sites. On one hand, this leads to the investigation of the magnetic properties and the Faraday rotation effect for the studied alloy, doped with different concentrations of cobalt (0.01, 0.05, 0.1, 0.15, 0.2, 0.25). On the other hand, we have created 0.01 of vacancy defects in Cd sites. Then, we raised the vacancy defect concentration to 0.05, keeping the same concentrations of cobalt. As a result, we have investigated that there is a magnetism appearing with the cobalt doping, while the vacancy defects in Cd sites affect the stability of the magnetic states. In general, it improves the ferromagnetic state that will be well explained in the discussion. Our calculations were performed using the KKR-CPA method within the spin-polarized density functional theory (DFT) with the local density approximation (LDA). The curves of the density of states (DOS) illustrate the results of this study which has been discussed, analyzed, and explained below. In addition, the energy of each case was calculated and given in the tables below for both the DLM (half of the cobalt spins are up while the other half are down) and the ferromagnetic state in order to confirm which one of them is stable. [ABSTRACT FROM AUTHOR]

In this work, inspiring form of the fullerene-C60 structures, we study the mixed X30Y30 fullerene-like structure and investigate its magnetic properties. In a such a structure, the carbons are assumed to be replaced by magnetic atoms having spin moments σ = 1/2 and S = 1. Firstly, we elaborate the ground-state phase diagrams in different physical parameter planes. In a second stage, we investigate the exchange coupling interaction effects in the absence or presence of both external magnetic and crystal fields. Using the Monte Carlo method, we carried out a study of the system magnetic properties and the thermal behavior of such a system for the ferromagnetic case. It is found that the critical temperature increases when increasing the coupling exchange interactions. On the other hand, the coercive magnetic field increases also when increasing the coupling exchange interactions. However, this physical parameter decreases when increasing the reduced temperature. [ABSTRACT FROM AUTHOR]

We present in this work the effects of the external magnetic field, the exchange anisotropy, the coupling exchange interaction and the temperature on the magnetic properties of the nanostructure systems. More exactly, the effect of the core-shell spin Ising systems has been also examined. A number of favorable phenomena such as the wetting magnetic and the layering transitions have been investigated. The Monte Carlo simulations have been used to investigate the behavior of these nanostructure systems and to obtain the interesting results presented in the form of the phase diagrams. [ABSTRACT FROM AUTHOR]

Monte Carlo (MC) simulation method with the Metropolis algorithm is used to study the magnetic and thermal phase transition properties of a spherical nanoparticle. The system consists of two concentric spheres of rays RC and RS, respectively (Rc < Rs). For r < Rc, the spin is σ = ±3 /2 and ±1 /2, and for RC < r ≤ RS, the spin is S = ±7 /2, + 5/2, ±3 /2, and ±1 /2 with antiferromagnetic interface coupling. Between RC and RS, the sites are populated with the probability (p). We present a detailed discussion on the magnetic and thermal phase transition characteristics of the system under consideration. Our investigations show that this system can be used as a magnetic nanostructure possessing potential applications in magnetism. [ABSTRACT FROM AUTHOR]

The kinetics of the semi-infinite Ising model in the presence of a time-dependent oscillating external field is studied within the framework of the mean-field approach. We use the Glauber-type stochastic dynamics to describe the evolution time of this system. We present a variety of phase in a semi-infinite cubic ferromagnet with spin-1 in two different, planes; phase diagrams contain (BF, S 1P, SP) phase, (BF, S 1F, SP) phase, completely ordered phase (BF, S 1F, SF) and completely disordered phase (BP, S 1P, SP), which strongly depend on interaction parameters. The nature first and second orders of the transitions is characterized by studying the thermal behaviors of the dynamic magnetizations. Furthermore, the system exhibits dynamical tricritical phenomenon and the reentrant behaviors. The magnetizations and phase space trajectories are given and discussed. [ABSTRACT FROM AUTHOR]

In this work, we investigate the effects of biaxial and uniaxial tensile strains on the electronic, optical, thermodynamic, and thermoelectric properties of the LiCu3Bi5 the first-principles density-functional theory. The electronic band structures indicate that this compound is a metal. The thermodynamic analysis of the Debye temperature data shows that increasing the dilatation strain can increase the mechanical and thermal stability of LiCu3Bi5. As soon as the temperature exceeds 300 K, the Dulong-Petit limit is reached, and the volume heat capacity virtually remains constant. According to optical characteristics like dielectric functions, absorption coefficients, and electron loss functions, this material has outstanding absorption capacity in the visible region. The highest value of the figure of merit in the absence of any strain along the c direction reaches its maximum at the value 0.06 indicating that this material could be a potential candidate for thermoelectric device applications. [ABSTRACT FROM AUTHOR]

In this paper, we study the magnetic properties and the effect of the Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions in a bilayer graphene structure with non-equivalent planes of a ferromagnetic consisting of the spins σ = 1 / 2 and S = 1. The studied system is formed by two magnetic planes (A and B), separated by a number of non-magnetic planes. In fact, the influence of the coupling exchange interactions, the external magnetic field, and the crystal field is investigated and presented as well as the ground-state phase diagrams. Using Monte Carlo simulations, we examine the behavior of the magnetizations and the total magnetization as a function of the values of system parameters. The effect of the RKKY interactions increases for increasing values of the number of non-magnetic planes; for this reason, the studied system becomes disorder when the number of non-magnetic planes increased. When the susceptibility peaks correspond to the reduced critical temperature ( T / J ), this critical temperature is displaced towards the lower temperatures. [ABSTRACT FROM AUTHOR]

In this paper, we study the magnetic order-disorder layering transitions in a polyamidoamine (PAMAM) dendrimer nanostructure, under the effect of a variable crystal field. This PAMAM dendrimer nanostructure is found in many scientific domains. Firstly, we examine the magnetic properties of this model consisting of the spin S=1 Ising ferromagnetic model in real nanostructure. At null temperature $\thinspace \left (T\mathrm {=0} \right )$ , we give and discuss the ground-state phase diagrams in different planes. For non-null temperature values, we applied the Monte Carlo simulations showing interesting results, summarized in different phase diagrams. We also examined the effect of the coupling exchange interactions on the order-disorder layering transitions of the studied system. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate and determine the magnetic properties and the magneto-caloric effect of the system MnAs with the spin moment ( S = 2). To attain this aim, we first use Ab initio method to determine the density of the state and exchange couplings of the compound. This stage is followed by analysis and discussion of ground-phase diagrams, and then by examination of all stable phases. To investigate further the compound, we establish the magnetic properties and the magneto-caloric effect of the compound in question by Monte Carlo simulation method in the framework of the Ising model, and consequently, we achieve a number of results such as the determination of the magnetization, the susceptibility, the specific heat and the Binder's fourth-order cumulate of the order parameter, the plotting of the effect of the exchange coupling and temperature on the hysteresis loop behaviors, the calculation of the Binder's fourth-order cumulate of energy, and finally the isothermal magnetic entropy change, adiabatic temperature change and relative cooling power (RCP) for the different external magnetic fields. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to study the magnetic properties of a fullerene-like structure geometry X , X , and X where the symbol X can be assigned to any magnetic atom. Such structures are formed by atoms with spin σ = 1/2. Using the Monte Carlo computation, the thermal behavior of the magnetizations and susceptibilities of such systems in the ferromagnetic case are studied. We find that the critical temperature increases non-linearly when increasing the number of atoms in the studied system. Otherwise, the coercive field increases linearly when the number of atoms in the structure increases. [ABSTRACT FROM AUTHOR]

In this work, we study the magnetic properties in a nano-hexagonal structure, based on a ferromagnetic Ising model. This system is formed by four hexagonal layers, with the mixed spin σ=1/2 in the inner and spin S=1 in the surface of our system. This latter is modeled by specific Hamiltonian containing different parameters which are the inner and external magnetic fields, the crystal magnetic field, and the exchange coupling interactions. In this study, we generated the ground state phase diagrams and then studied the magnetizations and the wetting phenomena at finite temperature. For this purpose, we used the Monte Carlo method. Moreover, we analyzed the wetting phenomena and the layering transitions appearing under the effect of different parameters of our Hamiltonian. [ABSTRACT FROM AUTHOR]

Using Monte Carlo simulations, we study the effect of the Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions in a bilayer olympicene structure, with mixed spins ( σ = 3/2 and S = 2) in the Blume-Capel model. The studied system is formed by two magnetic layers ( N and N ), separated by a number of non-magnetic layers (NM). We first elaborate the ground-state phase diagrams and then we found that from 4 × 5 = 20 phases possible, only 12 configurations are found to be stable. For low reduced temperature values, the partial magnetizations are found to be in good agreement with the corresponding ground-state phase diagrams. The critical temperature is displaced towards lower temperatures. This is due to the fact that the increasing of the number of non-magnetic layers increases the effect of the RKKY interaction. We have interpreted the behaviors of the magnetic hysteresis for this model. [ABSTRACT FROM AUTHOR]