M. GHELLAB Torkia

Alkaline amides XNH₂ (X = Li, Na) were studied to assess their potential for hydrogen storage applications using first-principles calculations. Structural analyses revealed that LiNH₂ crystallizes in a tetragonal structure (space group I-4), while NaNH₂ adopts an orthorhombic structure (space group Fddd). The electronic band structure, calculated using the Generalized Gradient Approximation (GGA), Local Density Approximation (LDA), and Engel-Vosko Generalized Gradient Approximation (EV-GGA), shows that both materials are wide-bandgap semiconductors with bandgap values of 4.45 eV for LiNH₂ and 3.97 eV for NaNH₂. The valence bands are dominated by [NH₂]⁻ states, which play a critical role in hydrogen storage. The mechanical stability of both compounds was confirmed by elastic constants, with LiNH₂ exhibiting superior mechanical strength compared to NaNH₂. Phonon dispersion analysis verified the dynamic stability of both materials. Optical properties, such as refractive index, reflectivity, and absorption coefficient, were evaluated, revealing high optical contrast, making these materials promising for optoelectronic applications. Thermal behavior analysis indicated that increasing temperature leads to higher entropy and internal energy, and lower free energy, favoring hydrogen desorption. The gravimetric hydrogen storage capacities were calculated as 8.78 wt% for LiNH₂ and 5.17 wt% for NaNH₂, highlighting their potential for energy storage. This study provides novel insights into the structural, electronic, mechanical, optical, and thermal properties of XNH₂, positioning LiNH₂ as a promising candidate for hydrogen storage and optoelectronic applications.

This study employs first-principles calculations to explore the structural, elastic, electronic, magnetic, and optical properties of the quaternary Heusler compounds CoFeYSb (Y = V, Ti). The structural analysis confirms that both compounds are most stable in the YI configuration. CoFeVSb is found to exhibit ferromagnetic behavior, while CoFeTiSb shows ferrimagnetism. Elastic constants, cohesion energy, and formation energy calculations further validate the stability of the magnetic (I) phase for both materials. Band structure analysis reveals that these compounds are half-metallic, achieving 100% spin polarization at the Fermi level, with spin-down energy gaps of 0.55 eV for CoFeVSb and 0.61 eV for CoFeTiSb. The total magnetic moments comply with the Slater-Pauling 24-electron rule, with values of 3 μB for CoFeVSb and 2 μB for CoFeTiSb. Optical investigations, including the dielectric function, absorption coefficient, and energy loss function, demonstrate strong absorption in the visible and ultraviolet ranges. These results highlight the potential of CoFeYSb compounds for advanced optoelectronic and spintronic applications, offering new opportunities for their integration into electronic and photonic technologies.

The substitution of Ge with Si in the ZnGeAs₂ chalcopyrite semiconductor and its impact on structural, electronic, optical, and thermoelectric properties have been systematically studied using density functional theory. This study demonstrates the tunability of material properties through alloying, revealing novel insights into the ZnGe₁₋ₓSiₓAs₂ (x = 0–1) system. The exchange-correlation energy was evaluated using the local density, generalized gradient, and modified Becke-Johnson schemes, ensuring accurate predictions. The calculated structural parameters and band gap energies for ZnGeAs₂ and ZnSiAs₂ exhibit excellent agreement with experimental data, validating the reliability of our approach.
Both ZnGeAs₂ and ZnSiAs₂ exhibit semiconductor characteristics with a direct band gap at the Γ point, making them promising for optoelectronic applications. The alloys show anisotropic optical behavior, with ZnGe₀.₂₅Si₀.₇₅As₂ demonstrating the highest refractive index and energy loss, making it a strong candidate for UV-shielding and optoelectronic devices. Thermoelectric analysis identifies ZnGe₀.₇₅Si₀.₂₅As₂ as the optimal composition, achieving a maximum Seebeck coefficient of 228.26 μV/K at 800 K. Moreover, by tuning the carrier concentration to n = 4.87 × 101⁸ cm⁻³, the Seebeck coefficient can be significantly enhanced to 449.44 μV/K. These findings highlight the potential of Si substitution to enhance material performance and provide a roadmap for tailoring the structural, optical, and thermoelectric properties of chalcopyrite semiconductors.

This course handout, Vibrations and Mechanical Waves, is designed to align with the LMD-S3 License training curriculum in the fields of Material Science (SM) and Science and Technology (ST). The content is structured into two parts, providing a comprehensive exploration of vibrations and wave propagation phenomena.
The first part, organized into five chapters, focuses on vibrations. Chapter one introduces the Lagrange formalism, which describes the oscillations of physical systems. Chapter two examines free linear oscillations of systems with one degree of freedom under low amplitude conditions. Chapter three addresses damped motion, incorporating the effects of viscous friction proportional to velocity. The concept of resonance in forced oscillations is detailed in chapter four. Finally, chapter five discusses vibrations in systems with multiple degrees of freedom, expanding the scope to more complex scenarios.
The second part of the course, spanning the final two chapters, is dedicated to wave propagation phenomena, offering a detailed treatment of the principles and applications of mechanical waves.
The course is presented in a logical and progressive manner, with each new concept supported by simple examples and practical problems designed to reinforce understanding. This structure ensures students can effectively assimilate the material, building a solid foundation in vibrations and mechanical waves for applications in material science and technology.

Keywords: Vibrations, Mechanical waves, Lagrange formalism, Resonance, Wave propagation.

In this study, we investigated the structural and electronic properties of Cs2GeBr6 and Cs2SiBr6, which belong to the perovskite family and are promising materials for photovoltaic applications. The calculations were carried out using the ab-initio method known as linearized augmented plane waves (FP-LAPW) within the framework of Density Functional Theory (DFT).
Our results regarding the structural properties, such as the lattice constant for Cs2GeBr6 (a=10.6032Å) and Cs2SiBr6 (a=10.5666Å), and the compressibility modulus and minimum energy obtained by LDA, are in agreement with theoretical values. These properties indicate significant structural stability, a key factor in improving the performance of these materials in photovoltaic applications.
The study of the electronic structure showed that the energy gap is direct for both Cs2GeBr6 and Cs2SiBr6, making these materials suitable candidates for solar cell applications, as direct energy gaps enhance light absorption efficiency. However, the calculated values of the energy gaps using LDA and GGA approximations were lower than experimental values, which is attributed to known deficiencies in Density Functional Theory (DFT). Nevertheless, the results for Cs2GeBr6 (GGA, Eg = 0.959eV) and Cs2SiBr6 (GGA, Eg = 0.933eV) were consistent with theoretical data.
We also studied the total and partial densities of states (DOS) for the two compounds, allowing us to identify the type of atoms and orbitals formed between the different elements in the compound. This deep understanding of the electronic properties helps improve the design of materials for use in solar cells.
We used the linearized augmented plane wave method (FP-LAPW) based on Density Functional Theory (DFT) to calculate the structural and electronic properties. We employed the Local Density Approximation (LDA) and Generalized Gradient Approximation (GGA) to calculate the exchange-correlation potential (XC) in order to obtain the structural properties such as the lattice constant and compressibility modulus, and the resulting values were consistent with the available practical results.
When using the LDA and GGA approximations to calculate electronic properties (energy bands and density of states), we observed significant improvement in the results with the GGA approximation compared to LDA, which increases the potential for using these materials in photovoltaic applications with higher efficiency.

This study presents a comprehensive investigation of the electronic and mechanical properties of Zintl hydrides XGaSiH (X = Sr, Ca, Ba) using density functional theory (DFT) and the FP-LAPW method within the WIEN2k package. The analyses include structural stability, electronic properties, and hydrogen interaction mechanisms in these compounds. The hydrides exhibit narrow band gaps ranging from 0.1 to 0.5 electron volts using GGA and LDA functionals, and from 0.6 to 1.0 electron volts using mBJ-GGA and mBJ-LDA functionals. Hydrogen storage capacities were determined to be 0.34%, 0.47%, and 0.40% for SrGaSiH, CaGaSiH, and BaGaSiH, respectively, highlighting their potential for energy storage applications. The elastic constants indicate that these compounds are mechanically stable, with notable anisotropy in the {100} plane and varying degrees of compressibility among different hydrides. The slightly interconnected hexagonal layers of Ga and Si contribute to enhancing the hydrogen storage capabilities of these materials. Electronic structure and density of states analyses reveal significant conductivity potential, with band gaps ranging from 0.1 to 1.0 electron volts depending on the computational method used. The unique combination of structural and electronic properties of XGaSiH compounds positions these materials as promising candidates for renewable energy applications [1].
These results provide a foundation for future research focusing on improving these materials through structural modifications or doping to enhance performance metrics such as hydrogen storage capacity and electrical conductivity. This study offers an in-depth insight into the fundamental properties of Zintl hydrides XGaSiH (X = Sr, Ca, Ba), indicating their significant potential for energy storage applications. With good hydrogen storage capacities and notable structural stability, these materials are particularly promising in the field of renewable energy. The findings enhance the current understanding of how performance can be improved through structural modifications or doping, opening new avenues for research in enhancing storage capacity and electrical conductivity. Future research in improving these materials will significantly contribute to the development of clean and sustainable energy technologies.

Using density functional and and Boltzmann transport theories, we investigate the thermoelectric transport properties

Materials exhibiting significant polarisation at high spin rates are considered the most promising candidates for spintronic devices. This study investigates the mechanical, optical, spin-polarised electronic structure, magnetism, and thermoelectric properties of CoIrMnX (where X = Sn, Sb). We performed calculations of quaternary Heusler alloys using first-principles calculations. The CoIrMnSn and CoIrMnSb compounds have the most stable Type III crystal structures, according to the calculations performed on the alloys under investigation. We found that the two alloys, CoIrMnSn and CoIrMnSb, possessed a half-metallic ferromagnetic structure, characterised by indirect band gaps of 1.008 eV and 0.806 eV in the predominant spin channels, respectively. Both alloys demonstrate a significant overall magnetic moment of 5 and 6 μβ, respectively. CoIrMnX (where X = Sn, Sb) are ferromagnetic half-metals with 100 percent spin polarisation, according to the results. The results of the elastic constants demonstrate the alloys' mechanical stability. We also investigated optical characteristics such as dielectric function, absorption, reflectance, and optical conductivity. CoIrMnX (where X = Sn and Sb) acts as an efficient absorber in the ultraviolet region and possesses a high refractive index. Alloys exhibit considerable potential as viable candidates for implementation in spintronic devices. The maximum ZT value for CoIrMnSn (CoIrMnSb) is 0.915 (0.6619). To achieve this value, it is necessary to either reduce the charge carrier concentration to n = 0.0812 × 1020 (0.0952 × 1020) cm−3 or the μ to 0.83843 (0.83806) Ryd. Substantially examined materials demonstrate considerable potential for application in the field of thermoelectrics.

This study presents a comprehensive investigation of the electronic, mechanical, and thermodynamic properties of Zintl phase hydrides XGaSiH (X = Sr, Ca, Ba) using Density Functional Theory (DFT) and the FP-LAPW method within the WIEN2k package. Our analysis covers the structural stability, electronic properties, and hydrogen interaction mechanisms in these compounds. The hydrides exhibit narrow band gaps, with values ranging from 0.1 to 0.5 eV using GGA and LDA functionals, and 0.6–1.0 eV with mBJ-GGA and mBJ-LDA. The hydrogen storage capacities are determined to be 0.34 wt %, 0.47 wt %, and 0.40 wt % for SrGaSiH, CaGaSiH, and BaGaSiH, respectively, highlighting their potential for energy storage applications. Thermodynamic properties, evaluated through the quasi-harmonic Debye model, provide insights into the Grüneisen parameter, heat capacity, and thermal expansion coefficient over a range of pressures (0–50 GPa) and temperatures (up to 1000 K). Elastic constants reveal that these compounds are mechanically stable, with a notable anisotropy in the {100} plane and varying degrees of compressibility among the different hydrides. Our study further highlights the slightly ordered hexagonal Ga and Si layers, which contribute to the enhanced hydrogen storage capabilities of these materials. The compounds demonstrate high structural stability, facilitating effective hydrogen retention and release at practical temperatures, making them promising candidates for hydrogen storage applications. Additionally, the analysis of electronic band structures and density of states suggests significant conductivity potential, with band gaps ranging from 0.1 to 1.0 eV, depending on the computational method used. The unique combination of structural, electronic, thermodynamic, and mechanical properties in XGaSiH compounds positions them as valuable materials for renewable energy applications. These findings lay the groundwork for future research focused on optimizing these materials through structural modifications or doping to enhance performance metrics such as hydrogen storage capacity and electrical conductivity.

High-spin-polarised materials are the most promising candidates for spintronic devices. Here, the spin-polarised electronic structure, magnetism, mechanical, and optical properties of RhFeMnZ and IrMnCrZ (where Z = Si, Ge) Quaternary Heusler alloys were calculated by first-principles calculations. The calculations show that type III for the RhFeMnSi, RhFeMnGe, and IrMnCrSi and type I for the IrMnCrGe compound configuration is the most stable crystal structure for the studied alloys. The four alloys were found to have a half-metallic ferromagnetic structure with indirect band gaps in the majority spin channels of 0.957, 0.66, 0.745, and 0.891 eV for RhFeMnSi, RhFeMnGe, IrMnCrSi, and IrMnCrGe, respectively. They exhibit an appreciable total magnetic moment of 4 μB for RhFeMnZ (Z = Si, Ge) and 2 μB for IrMnCrZ (Z = Si, Ge). The results show that RhFeMnZ and IrMnCrZ (where Z = Si, Ge) are ferromagnetic half-metals with 100 % spin polarisation. The results of the elastic constants demonstrate the mechanical stability of RhFeMnZ and IrMnCrZ (where Z = Si, Ge) alloys. Optical properties such as dielectric function, absorption, reflectance, optical conductivity, and other optical properties were also probed. In the ultraviolet region, RhFeMnZ and IrMnCrZ (where Z = Si, Ge) are effective absorbers and have a high refractive index. Alloys are promising candidates for potential applications in spintronic devices.

We present an extensive analysis of the structural, electronic, optical, elastic, and thermoelectric properties of compounds, where represents either sulfur () or selenium (). Our approach employed the all-electron full potential linearized augmented plane wave (FP-LAPW) technique, offering a comprehensive understanding of these materials' characteristics. The calculated lattice constants (), the unit cell height (), and the c/a ratio closely match experimental data, affirming the accuracy of our calculations. A pivotal focus of our study was on the electronic properties, including the indirect bandgaps () and (). We found that exhibited an indirect bandgap () of 2.504 eV, while possessed a slightly lower value of 1.878 eV. This variation was primarily attributed to the intricate interactions among bismuth, sulfur, and selenium atoms, particularly involving orbital interactions. Additionally, we explored the optical characteristics of these compounds, determining their maximum absorption wavelengths. exhibited an absorption peak at 4.476 eV, whereas displayed a slightly lower maximum absorption at 3.741 eV. Moreover, showcases a higher dielectric constant, which augments its potential for optoelectronic applications. A critical aspect of our research is the assessment of the elastic properties, elucidating that both compounds exhibited fragility and anisotropy. We observed that at 300 K, the lattice thermal conductivity () for and was measured at and , respectively, indicating low thermal conductivity. At 1000 K, both BiGa2S4, and BiGa2Se4 exhibit significant ZT values of 0.8389 and 0.8722, respectively. The ZT values of the p-type semiconductors are notably higher than those of the n-type. At T = 900 K, the optimized ZT values for BiGa2S4, and BiGa2Se4 are found to be 0.82909 and 0.90548, respectively. Achieving these values requires either increasing the concentration of charge carriers to n = 0.11715 x 1022 cm−3 for BiGa2S4 and n = 0.0812 x 1022 cm−3 for BiGa2Se4, or reducing the chemical potentials by 0.40151 Ryd and 0.38001 Ryd, respectively.

This study employs a first-principles approach to comprehensively investigate the structural, electronic, elastic, and optical properties of two distinct inorganic perovskite phases of CsPbI3, identified as C–CsPbI3 and O–CsPbI3. Utilizing the Wien2K code, simulations are conducted employing various density functional theory (DFT) approximations, including local density approximation (LDA), generalized gradient approximation (GGA), the modified Becke–Johnson potential (mBJ), and the Tran-Blaha modified Becke–Johnson potential (TB-mBJ). Our analysis demonstrates that the orthorhombic phase exhibits greater energetic stability and mechanical robustness compared to the cubic phase. Furthermore, optical analyses reveal a direct bandgap in the compound, with key parameters calculated and interpreted. Notably, both phases demonstrate exceptional electronic, mechanical, and optical properties, suggesting their potential applications in optoelectronics, photovoltaics, and photovoltaic cells. Consequently, this study positions both the cubic and orthorhombic phases of CsPbI3 as promising materials warranting further exploration and development in these technological domains.

Due to its potential uses in thermoelectrics, spintronics, and other sectors, double half-Heusler compounds have recently attracted much attention. This study presents thefi rst-ever report on the structural, electronic, optical, elastic, and thermoelectric characteristics of the double half Heusler (DHH) compounds ScTaPd2Sn2 and ScTaPt2Sn2, employing density functional theory ( DFT ). Using the EV-GGA approximation, the estimated band structures exhibit a semiconductor behavior with an indirect bandgap of 0.549 eV and 0.851 eV, respectively. In addition, we examined optical characteristics. Our material structural stability and stiffness were con firmed using elastic characteristics. Boltzmann’s semiclassical theory attempts to explain a simulation concept in the BoltzTrap software. According to the thermoelectric investigation, these DHH are a p-type material, a candidate for thermoelectric application, specifi cally when doped.

Structural, electronic and mechanical properties of ZrCo1−xIrxSb Half-Heusler alloys with varying x concentrations (x = 0, 0.125, 0.25, 0.375, 0.5, 0.625, 0.75, 0.875, and 1) were studied by performing the exchange-correlation (XC) energy evaluated using the local density (LDA) and generalized gradient (GGA) approximations. The calculated lattice constant, bulk modulus, and band gap energy of the ternary alloy show good agreement with previous theoretical predictions. The results indicate that an increase in Ir atom concentration in the alloy leads to an enlargement of the lattice constant (from 6.10 to 6.36 Å) and bulk modulus (from 138.09 to 149.70 GPa), resulting in increased volume and hardness of the compound. Moreover, the Engel-Vosko generalized gradient approximation (EVGGA) and modified Becke-Johnson (mBJ) schemes were employed to improve the calculations of the band structure and density of states. The studied alloys exhibit semiconductor characteristics, with a direct band gap for both x = 0.75 and x = 0.875 concentrations and an indirect band gap for the rest of the concentrations. The computed elastic constants for ZrCo1−xIrxSb alloys satisfy the requirements for mechanical stability. The VRH approximations have been used to determine the bulk modulus, shear modulus, Young's modulus, Poisson's ratio and Hardness. In addition, we also determined the anisotropy factor, sound velocities and Debye temperature.

In this work, we delve into the investigation of the structural, electronic, and optical properties of Ba2NbBiS 6 and Ba2TaSbS 6chalcogenide-based double perovskites, which are structured in the cubic space group Fm3m form. We have performed ¯rst-principles calculations using density functional theory (DFT) to study the above properties. The electronic band structure and density of states of this compound have been investigated, and their results show that Ba2NbBiS 6 and Ba2TaSbS 6 exhibit a semiconducting nature with an indirect energy gap of 1.680 eV and 1.529 eV, respectively. Furthermore, an investigation was conducted on the optical properties of the compounds throughout the energy range spanning from 0 eV to 55 eV. This investigation focused on many parameters, including dielectric functions, optical re°ectivity, refractive index, extinction coe±cient, optical conductivity, and electron energy loss. The optical data obtained from the calculations reveals that all compounds demonstrate isotropy in optical polarization. Furthermore, it has been noted that our compounds exhibit absorption properties inside the ultraviolet (UV) region. Consequently, these materials hold promise as potential candidates for various applications, such as UV photodetectors, UV light emitters, and power electronics. This is primarily attributed to their inherent absorption limits and the presence of prominent absorption peaks in this spectral range. In brief, chemical mutation techniques have been employed to manipulate the characteristics of double-sul¯de perovskites to develop durable and environmentally friendly perovskite materials suitable for solar purposes.

The mechanical and thermodynamic properties of polyanionic hydrides XAlSiH(X = Sr, Ca, and Ba) were evaluated using density functional theory(DFT ). The thermal parameters of XAlSiH hydrides, such as the Grüneisen parameter γ , heat capacity, and thermal expansion coef ficient, were computed for the first time. The quasi-harmonic Debye model was used to determine these parameters over a range of pressures ( 0– 40 GPa ) and temperatures ( 0 –1000 K ). The gravimetric hydrogen storage capacities for BaAlSiH, SrAlSiH, and CaAlSiH were found to be 0.52%, 0.71%, and 1.05%, respectively. The hydrogen desorption temperatures for these compounds were also simulated at 748.90 K, 311.57 K, and 685.40 K. Furthermore, semiconducting behavior with an indirect bandgap value between 0.2 and 0.7 eV was exhibited by these compounds using the GGA and LDA approximation, and between 0.7 and 1.2 eV using the mBJ-GGA and mBJ-LDA approximation. Accurate elastic constants for single crystals were obtained from the calculated stress– strain relationships. The elastic constants for the XAlSiH compounds were signi fi cantly higher than those for other hydrides. The [001] direction was more compressible than the[100] direction in the
hexagonal structure of XAlSiH. A lower bulk modulus than metallic hydrides was exhibited by these materials, indicating that XAlSiH compounds (X = Sr, Ca, and Ba) were highly compressible. The melting temperature for CaAlSiH was higher than that for SrAlSiH and BaAlSiH. Consequently, the decomposition temperature for XAlSiH (X = Sr and Ba ) at which hydrogen was released from a fuel cell was lower than that for CaAlSiH. The bonding behavior of CaAlSiH was more directional than that of SrAlSiH and BaAlSiH. Brittle materials were XAlSiH ( X = Sr, Ca, and Ba) . Our PBE calculations yield linear compressibility and orientation-dependent Young’s modulus. Materials composed of hexagonal XAlSiH(where X represents Sr, Ca, or Ba elements) exhibit anisotropy in Young ’s modulus but isotropy in bulk modulus.

The present study utilizes first-principles calculations grounded in density-functional theory (DFT) to examine the thermoelectric, electronic, elastic, optical, and structural properties of BiGaIn2S6. It is demonstrated that the approximated structural parameters (a, b, c, β, c/a, b/a), as well as atomic sites, correspond to the experimental data. Based on the measured elastic properties, it can be concluded that the investigated material possesses anisotropy and ductility. The computation of the electronic properties of our compound unveiled its semiconducting characteristics. The mBJ-LDA method was employed to ascertain that the compound exhibits an indirect band gap (Γ→Γ-E) of 2.711 eV. Based on the computational outcomes, it can be concluded that the real part of dielectric complex and refractive index exhibit a degree of anisotropy. The compound exhibits promising potential for optoelectronic applications due to its tolerable values of optical properties such as optical conductivity, absorption aspect, refractive index, and reflectivity. The positive Seebeck coefficient obtained from the calculation indicates that this compound can be classified as a p-type material. The semiconductor BiGaIn2S6 exhibits a maximum ZT value of 0.98741 when the charge carrier concentration is increased to n = 0.14494 × 1022 cm−3 or when the chemical potential lowers to 0.47499 Ryd. The material being studied demonstrates potential uses in the fields of thermoelectric and optoelectronic devices.

The present study explores the structural, optoelectronic, and thermoelectric properties of potassium tin halide vacancy-ordered double perovskites K2SnX6 (X = Cl, Br, and I) in their stable monoclinic phase. Our study uses first-principles calculations based on density functional theory (DFT ) . Electronic band structures reveal direct band gaps for K2SnCl6 and K2SnBr6, while K2SnI6 exhibits an indirect band gap. Theoretical computations utilising the modi fied Becke-Johnson potential (mBJ-GGA) demonstrate that the optical band gaps of K2SnCl6,K2SnBr6, and K2SnI6 decrease in the following order: 2.581 eV, 1.707 eV, and 4.126 eV, respectively. These values render the materials suitable for photovoltaic applications. Analysis of dielectric functions, absorption coefficients, and refractive indices demonstrates their potential as light-absorbing materials. We evaluate the thermo- electric properties, including electronic and lattice thermal conductivities, Seebeck coef fi cients, and power factors, which lead to favorable thermoelectric performance. The maximumfi gure of merit (ZT) values of 0.58, 0.69, and 0.50 are achieved for K2SnCl6,K2SnBr6, and K2Sn, respectively, at 500 K. Thesefindings highlight the potential of these materials for applications in solar cells and thermoelectric devices, emphasising their effectiveness at elevated temperatures.

Since Groot’s discovery of the first half metallic material, NiMnSb, in 1983, the scientific community has become increasingly interested in the study of Heusler alloys. Due to their unusual and interesting structural characteristics, magnetic properties, and many features, including metallic, insulating, semiconducting, half-metallic, and spin gapless
semiconducting, these materials have garnered a lot of attention. These materials are used for spintronics and magnetoelectronics applications such as spin filters, spininjection, magnetic tunnel junctions, giant magnetoresistance, spin transfer torque,memory devices, spin caloritronics, magnetic sensors, and neuromorphic and stochastic computing.
In this work, we have studied the structural, elastic, electronic and magnetic properties of CoFeVSb Heusler compound basing on the density functional theory. The most stable structure has been found to be energetically favorable in face- centered cubic (FCC) structure with space group F43m, in which Co, Fe, V, and Sb atoms are located at 4d, 4c, 4b and 4a Wyckoff positions, respectively. In the stable state, CoFeVSb is ferromagnetic. The determined elastic constants (Cij) show that CoFeVSb is mechanically stable and ductile, and exhibit a notable elastic anisotropy. Electronic calculations indicate that CoFeVSb exhibit half-metallic characteristics with high spin polarisation. For the spin-down, the Fermi level is located between the valence bands 3t1u and the conduction bands 2eu, which leads to a semiconductor behavior with an indirect band gap Γ-X of 0.52 eV. The total magnetic moment of these alloys is found to be equal to 3 µB which follows the Slater Pauling rule, which makes it hopeful in spintronic applications.