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We use Density Functional Theory and Monte Carlo simulation to investigate the structural, electronic, and magnetic properties of the ferromagnetic inverse Heusler alloys Fe2RhSi and Fe2RhGe. The metallic nature of both alloys is confirmed using GGA, GGA+U, and meta-GGA methods. The calculated magnetic moments are 5.017μB for Fe2RhSi and 5.177μB for Fe2RhGe, aligning well with experimental findings. Spin polarization calculations yield 70% for Fe2RhSi and 53.03% for Fe2RhGe using the GGA method, while other methods produce values below 30%. Additionally, GGA+U calculations indicate a martensite transition at approximately c∕a=1.08 for both alloys without affecting their magnetic state. The Curie temperatures are around 900K for Fe2RhGe and Fe2RhSi, which closely match experimental data. The high spin polarization and Curie temperature make Fe2RhSi a promising candidate for spintronic applications. [ABSTRACT FROM AUTHOR]

This work aims to investigate the structural stability, magnetic and electronic properties of M3AlC antiperovskites using density functional theory (DFT) and Monte Carlo simulation. The obtained ground state results reveal that the antiperovskites M3AlC are stable in the ferromagnetic (FM) state with a metallic character. The calculated total magnetic moments are 5.21 μ B and 3.34 μ B for Mn3AlC and Fe3AlC, respectively, with the total moments mainly from the M atom. The ferromagnetic behavior is confirmed by computing the density of state at Fermi level and verified the Stoner criterion. The magnetic and magnetocaloric behavior of M3AlC is investigated using Monte Carlo simulation and the obtained results demonstrate that the transition from ferromagnetic to paramagnetic state occurs at T C = 3 0 0 K and T C = 2 3 0 K for Mn3AlC and Fe3AlC, respectively. These values of T C are in good agreement with the experimental results. The magnetocaloric effect and critical behavior are studied and the obtained values of magnetic entropy change | Δ S mag | at 4.5 T is about 4.242 J/kg.K and 3.666 J/kg.K and the relative cooling power (RCP) are 342.434 J/kg.K and 325.26 J/kg.K for Mn3AlC and Fe3AlC at 4.5T, indicating that these compounds are more appropriate for magnetic refrigeration. Finally, the critical exponents (β , γ , δ) are calculated and the obtained values are close to the values of mean-field model. [ABSTRACT FROM AUTHOR]

In this paper, we report the optoelectronic, thermoelectric properties and dynamic stability under the pressure of LiGaC half-Heusler within the Density Functional Theory (DFT) and semi-classical Boltzmann Transport Theory (BTT). The obtained results of the ground state show that the compound is structural, chemical, mechanical and dynamically stable in type I structure and maintains its stability under pressure. The obtained electronic properties reveal that the compound has a semiconducting nature with an indirect bandgap and the bandgap values slightly increase with pressure increase. The optical properties such as real and imaginary parts of dielectric function, refractive index and extinction coefficient, reflectivity and absorption coefficient and optical conductivity are calculated and discussed. The highest peaks of reflectivity and absorption coefficient are found in the ultra-violet (UV) region, suggesting that the compound LiGaC has a high potential for use in UV optoelectronic applications. The thermoelectric properties are also calculated in the temperature range from 300 K to 900 K and pressure range from 0 GPa to 40 GPa. At 300 K and for all pressures selected, the maximum value of figure of merit is close to unity. Finally, we could make our conclusion that LiGaC is well suitable for multiple optical and thermoelectric applications. [ABSTRACT FROM AUTHOR]

The Ni substitution effect on the structural, magnetic, electronic, elastic, thermodynamic and thermoelectric properties of C o 2 - x N i x M n S b Heusler alloys has been investigated employing the density functional theory (DFT). The results show that the C o 2 M n S b is stable in the ferromagnetic structure (FM) and acts as half-metal. Thus, the substitution of Co by Ni causes an increase in the inter-atomic distance, and it brings not only in FM interactions but also in the total magnetic moment as well which decreases from 6 μ B to 4.04 μ B . The electronic properties of C o 2 - x N i x M n S b have undergone a transition phase from half-metallic to metallic character due to the substitution effect of Co by Ni atom. According to the estimated elastic constants, Debye entropy and vibrational free energy, the compounds are mechanically and thermodynamically stable. Hence, both the phonon dispersion curves and the phonon density of states are also calculated and demonstrate that the compound is dynamically stable for x = 0 , 1 and dynamically unstable for x = 2 . Moreover, the semi-classical Boltzmann transport theory in combination with DFT was used to evaluate and discussed the thermoelectric properties under temperature and substitution of Co by Ni. [ABSTRACT FROM AUTHOR]

The structural, electronic and magnetic properties of the delafossite material CuFeO 2 were studied using Density Functional Theory (D F T) combined with Monte Carlo simulation (M C S). The structural stability was verified in this work and showed that this material is antiferromagnetic (AFM). The density of states (DOS) carried out using the generalized Perdew–Burke–Ernzerhof gradient (P B E - G G A), Tran-Balaha modified Becke–Johnson exchange potentials (T B - m B J ; n m B J) and the G G A ＋ U show that the compound has a metallic behavior in P B E - G G A and semiconductor behavior in T B - m B J , n m B J and G G A ＋ U approximations. The obtained partial magnetic moment was used to study the magnetic behavior by Monte Carlo simulation, particularly, the evolution of magnetization as a function of temperature and phase transition. The results of M C S showed the presence of two-phase transitions: ferromagnetic–antiferromagnetic (F M - A F M) first-order phase transition and antiferromagnetic–paramagnetic (A F M - P M) second-order phase transition. The Neel temperatures found are T N 2 = 11. 2 K for the first transition and T N 1 = 16. 6 K for the second transition. [ABSTRACT FROM AUTHOR]