SALIMA Saib

MEBARKI Djalel

Etude de premiers principes des propriétés mécaniques, thermodynamiques, vibrationnelles et supraconductrices des composés intermétalliques

مساعدي سلمى

دراسة ومقارنة الخواص الكهروضوئية ألشباه الموصالت ذات أساس نتر وجيني

berbache billel

Etude par simulation des propriétés physiques des semi-conducteurs

Adel Allal

Etude ab-initio des propriétés physiques des nouveaux matériaux de sulfure, de terre rare et d’Aclalin ABS2

dilmi souad

Calcul du premier principe des propriétés physiques des matériaux supraconducteurs

HERIZI Hadjar

Etude théorique des propriétés fondamentales du nitrure de Bore

CHELLALI Sara

Etude comparative des propriétés optoélectroniques et mécaniques des semiconducteurs

Oudina Meryem

Etude ab initio des propriétés fondamentales du Carbure de Lutécium.

Henanou Khadidja

Étude des propriétés fondamentales de carbure d'yttrium

This study presents a comprehensive first-principles investigation of HgSe in its zinc blende (B3) and high-pressure cinnabar (B9) phases, analyzing structural, electronic, elastic, vibrational, and thermodynamic properties using density functional theory. Our calculations reveal a pressure-induced B3 → B9 phase transition at 2.75 GPa (theoretical value) and 0.77 GPa (experimentally calibrated value), with the B9 phase showing anisotropic compressibility and enhanced mechanical stability. Electronic structure calculations with the B3LYP hybrid functional demonstrate that B3-HgSe is a narrow direct-gap semiconductor (0.14 eV at the Γ-point), while B9-HgSe exhibits an indirect gap (1.40 eV), both tunable under pressure. Phonon calculations confirm the dynamical stability of both phases. Thermodynamic properties reveal the B9 phase's superior thermal stability, with a Debye temperature of 162.6 K and ductile mechanical behavior. These findings provide crucial insights into HgSe's potential applications in infrared optoelectronics, pressure sensors, and topological devices, while resolving longstanding discrepancies in previous studies of this complex material system.

Citation

SALIMA Saib , , (2026-02-01), First-Principles Investigation of Structural, Electronic, Elastic, Vibrational, and Thermodynamic Properties of HgSe in Zinc Blende (B3) and Cinnabar (B9) Phases, Chemical Physics, Vol:601, Issue:601, pages:112960, elsevier

Through comprehensive first-principles calculations coupled with Boltzmann transport theory, we systematically investigate the strain-dependent structural, mechanical, electronic, and thermoelectric properties of monolayer ZrX2 (X = S, Se). Our mechanical analysis reveals both materials maintain exceptional stability under biaxial strains ranging from −10 % to +10 %, with ZrS2 exhibiting superior mechanical robustness as evidenced by its higher Young's modulus (73.95 N/m) compared to ZrSe2 (63.70 N/m). Detailed electronic structure calculations employing the TB-mBJ potential demonstrate these monolayers are indirect band gap semiconductors, with fundamental gaps of 1.8 eV for ZrS2 and 1.16 eV for ZrSe2. Notably, compressive strain induces dramatic electronic transitions, reducing the band gap progressively until ZrSe2 undergoes a complete semiconductor-to-metal transition at −10 % strain. The thermoelectric transport properties show remarkable strain sensitivity. Applied biaxial strain enhances the power factor by an order of magnitude, reaching exceptional values of 2.4 × 1011 W/mK2s for ZrSe2 at −6 % strain. Comparative analysis reveals n-type doping consistently outperforms p-type configurations in thermoelectric efficiency across all strain conditions. These enhancements originate from strain-induced modifications to both electronic band structures and carrier scattering mechanisms. Our combined mechanical, electronic, and thermoelectric characterization provides fundamental insights into the strain-response of ZrX2 monolayers, demonstrating their exceptional tunability for next-generation flexible electronics, strain sensors, and high-efficiency energy conversion devices. The comprehensive dataset presented here establishes a foundation for future experimental investigations and device applications of these promising 2D materials.

Citation

SALIMA Saib , , (2026-01-01), Strain-engineered electronic and thermoelectric properties of ZrX2 (X=S, Se) monolayers: A first-principles study, Chemical Physics, Vol:175, Issue:175, pages:116384, elsevier

This study reports a first-principles investigation of the structural, mechanical, electronic, and vibrational properties of In3Sc in several crystal structures: AuCu3 (Pm3̲ m), Al3Ti (I4/mmm), Ni3Sn (P63/mmc), and BiF3 (Fm3̲ m), with a focus on pressure effects. Calculated equilibrium lattice constants, bulk, shear, and Young’s moduli show good agreement with experimental and theoretical data, especially for the cubic AuCu3 phase. Elastic constants, examined with the Born stability criteria, reveal that the cubic (SG 221), tetragonal (SG 139), and hexagonal (SG 194) phases are mechanically stable at zero pressure, while the BiF3-type cubic (SG 225) is unstable. Pressure-dependent variations in lattice parameters, bulk modulus, and elastic moduli, captured by polynomial fits, demonstrate stiffening effects and pressure-induced phase transitions. Band structures and density of states confirm metallicity in all stable phases, with In–Sc hybridization governing bonding. Phonon dispersions and Grüneisen parameters, calculated under compression, establish the dynamical stability of the mechanically stable structures and provide insight into vibrational and thermal behavior. Debye temperature and sound velocities highlight favorable thermal-transport features. Altogether, the results clarify the intrinsic mechanical and thermodynamic response of In3Sc, supporting its potential as a promising intermetallic for structural and functional use under extreme conditions.

Citation

SALIMA Saib , , (2025-10-31), First-Principles Investigation of Pressure-Induced Structural, Elastic, and Vibrational Properties of In3Sc, Crystals, Vol:15, Issue:11, pages:946, Advancing Open Science

We investigate the phase stability, elastic properties, dynamical behavior, dielectric response, and polaron characteristics of zinc-blende CdSe under hydrostatic pressure using first-principles calculations within the generalized gradient approximation (GGA). The computed zinc-blende to rock-salt phase transition occurs at 2.65 GPa, consistent with experiment. Elastic constants C11 and C12 increase with pressure, while C44 decreases. The static dielectric constant decreases under pressure, whereas the high-frequency constant rises. Phonon dispersion shows all modes remain positive up to 3 GPa, confirming dynamical stability. The piezoelectric constant increases linearly from 0.82 to 0.92 C/m² in the 0-3 GPa range. Both electron and polaron effective masses increase with pressure, while the Fröhlich coupling parameter decreases, indicating weaker electron-phonon interaction. These findings provide detailed insight into the mechanical, dielectric, and transport properties of CdSe under compression, emphasizing its potential for pressure-tunable optoelectronic applications.

Citation

SALIMA Saib , , (2025-10-09), Material properties of zinc-blende CdSe under pressure: phase stability, mechanical behaviour, dielectric response, and polaron effects from first principles, Phase Transitions, Vol:98, Issue:9, pages:623–638, tandfonline

We investigate the phase stability, elastic properties, dynamical behavior, dielectric response, and polaron characteristics of zinc-blende CdSe under hydrostatic pressure using first-principles calculations within the generalized gradient approximation (GGA). The computed zinc-blende to rock-salt phase transition occurs at 2.65 GPa, consistent with experiment. Elastic constants C11 and C12 increase with pressure, while C44 decreases. The static dielectric constant decreases under pressure, whereas the high-frequency constant rises. Phonon dispersion shows all modes remain positive up to 3 GPa, confirming dynamical stability. The piezoelectric constant increases linearly from 0.82 to 0.92 C/m² in the 0-3 GPa range. Both electron and polaron effective masses increase with pressure, while the Fröhlich coupling parameter decreases, indicating weaker electron-phonon interaction. These findings provide detailed insight into the mechanical, dielectric, and transport properties of CdSe under compression, emphasizing its potential for pressure-tunable optoelectronic applications.

Citation

NADIR Bouarissa , FOUZI Amari , SALIMA Saib , , (2025-10-09), Material properties of zinc-blende CdSe under pressure: phase stability, mechanical behaviour, dielectric response, and polaron effects from first principles, Phase Transitions, Vol:98, Issue:12, pages:623-638, Taylor & Francis Online

This work presents a thorough analysis of the electronic, optical, and thermodynamic characteristics of ferromagnetic manganese selenide (MnSe) in both zinc-blende and rock-salt phases. Utilizing plane wave pseudo-potential calculations within the framework of spin-polarized density functional theory, our analysis offers a comprehensive evaluation. The calculated lattice parameters demonstrate a high level of concordance with available experimental data. Our findings indicate that MnSe compounds are semiconductors, as determined by their electronic band structures and density of states. Significant observations include the reduction in magnetic moments under increasing pressure, up to 10 GPa. Furthermore, we provide a detailed analysis of energy-dependent linear optical functions, including the complex dielectric function, complex refractive index, and reflectivity, and discuss their implications. Along with providing forecasts and in-depth discussions, our work clarifies the dependency of several thermodynamic variables on temperature and pressure for the compounds under investigation, including the bulk modulus, heat capacity, and thermal expansion coefficient.

Citation

NADIR Bouarissa , FOUZI Amari , SALIMA Saib , Adel Allal, , (2025-09-16), Ab Initio Investigation of Physical Properties of Ferromagnetic Manganese Selenide in the Zinc-Blende and Rock-Salt Structures under Hydrostatic Pressure, Physics of the Solid State, Vol:67, Issue:, pages:783–794, Springer Nature

Abstract A comprehensive first-principles investigation has been conducted on the α-phase LiGaSi1−xCx alloy to explore its structural, mechanical, electronic, thermodynamic, and lattice dynamical properties. The study employs density functional theory (DFT) within the plane-wave pseudopotential method, using the alchemical mixing approximation as implemented in the ABINIT code. Ground-state properties, including lattice constants, bulk modulus, elastic constants (Cij), Young’s modulus (E), shear modulus (G), and energy gaps, were calculated for the parent compounds LiGaSi and LiGaC, showing strong agreement with previously reported theoretical results. For the LiGaSi1−xCx alloy, these properties are reported here for the first time, providing new insights into its compositional dependence and mechanical stability. Electronic structure analysis, performed using the Tran–Blaha modified Becke–Johnson (TB-mBJ) exchange–correlation potential, reveals that the alloy exhibits an indirect bandgap (Γ to X) across all compositions, with the bandgap tunable from 0.59 eV to 1.51 eV depending on the carbon content. This tunability suggests promising potential for optoelectronic applications such as photosensors and light-emitting diodes (LEDs). Thermodynamic properties, including unit cell volume, bulk modulus, thermal expansion coefficient, heat capacity, and entropy, were examined as functions of temperature and carbon concentration. Phonon dispersion relations and phonon frequency analyses confirm the dynamical stability of the α-phase LiGaSi1−xCx alloy across the full compositional range studied.

Citation

SALIMA Saib , , (2025-08-26), Computational Investigation of structural, mechanical, electronic, thermodynamic, and lattice dynamical properties of α-phase LiGaSi1−xCx alloys for advanced energy applications, Physica Scripta, Vol:100, Issue:100, pages:085998, iopscience.i

A comprehensive first-principles investigation has been conducted on the α-phase LiGaSi1−xCx alloyto explore its structural, mechanical, electronic, thermodynamic, and lattice dynamical properties.The study employs density functional theory (DFT) within the plane-wave pseudopotential method,using the alchemical mixing approximation as implemented in the ABINIT code. Ground-stateproperties, including lattice constants, bulk modulus, elastic constants (Cij), Young’s modulus (E),shear modulus (G), and energy gaps, were calculated for the parent compounds LiGaSi and LiGaC,showing strong agreement with previously reported theoretical results. For the LiGaSi1−xCx alloy,these properties are reported here for the first time, providing new insights into its compositionaldependence and mechanical stability. Electronic structure analysis, performed using the Tran–Blahamodified Becke–Johnson (TB-mBJ) exchange–correlation potential, reveals that the alloy exhibits anindirect bandgap (Γ to X) across all compositions, with the bandgap tunable from 0.59 eV to 1.51 eVdepending on the carbon content. This tunability suggests promising potential for optoelectronicapplications such as photosensors and light-emitting diodes (LEDs). Thermodynamic properties,including unit cell volume, bulk modulus, thermal expansion coefficient, heat capacity, and entropy,were examined as functions of temperature and carbon concentration. Phonon dispersion relationsand phonon frequency analyses confirm the dynamical stability of the α-phase LiGaSi1−xCx alloyacross the full compositional range studied.

Citation

NADIR Bouarissa , SALIMA Saib , Samia BEN YETTOU , Bachiri Zeyneb, , (2025-08-26), Computational investigation of structural, mechanical, electronic, thermodynamic, and lattice dynamical properties of α-phase LiGaSi1-xCx alloys for advanced energy applications, Physica Scripta, Vol:100, Issue:, pages:085998, IOP Science

We have conducted a comprehensive first-principles investigation of the electronic structure, elastic properties, lattice dynamics, thermodynamic behavior, and superconductivity of cerium carbide (CeC2). By employing both plane-wave pseudopotential and all-electron linearized augmented plane wave methods, we confirm the metallic nature of CeC2 , with Ce-4f states playing a dominant role near the Fermi level. Elastic constant analysis indicates mechanical instability above 9.96 GPa, while temperature-dependent predictions of lattice parameters and bulk modulus exhibit strong agreement with experimental trends. Our thermodynamic calculations yield entropy values consistent with available data and confirm the dynamic stability of the structure, supported by the absence of imaginary phonon frequencies across the Brillouin zone. Moreover, analysis of the Eliashberg spectral function reveals that both cerium and carbon vibrations contribute significantly to the superconducting mechanism. The electron-phonon coupling constant (λ < 1) classifies CeC2 as a weak-coupling Bardeen–Cooper–Schrieffer (BCS) superconductor. The calculated superconducting critical temperature agrees with experimental observations at zero pressure and is predicted to decrease under compression.

Citation

SALIMA Saib , , (2025-08-09), High-Pressure Insights into the Material Properties of Cerium Carbide, Journal of Electronic Materials, Vol:54, Issue:10, pages:9016–9028, springer

We have conducted a comprehensive first-principles investigation of the electronic structure, elastic properties, lattice dynamics, thermodynamic behavior, and superconductivity of cerium carbide (CeC2). By employing both plane-wave pseudopotential and all-electron linearized augmented plane wave methods, we confirm the metallic nature of CeC2 , with Ce-4f states playing a dominant role near the Fermi level. Elastic constant analysis indicates mechanical instability above 9.96 GPa, while temperature-dependent predictions of lattice parameters and bulk modulus exhibit strong agreement with experimental trends. Our thermodynamic calculations yield entropy values consistent with available data and confirm the dynamic stability of the structure, supported by the absence of imaginary phonon frequencies across the Brillouin zone. Moreover, analysis of the Eliashberg spectral function reveals that both cerium and carbon vibrations contribute significantly to the superconducting mechanism. The electron-phonon coupling constant (λ < 1) classifies CeC2 as a weak-coupling Bardeen–Cooper–Schrieffer (BCS) superconductor. The calculated superconducting critical temperature agrees with experimental observations at zero pressure and is predicted to decrease under compression.

Citation

NADIR Bouarissa , SALIMA Saib , Souad Dilmi, Djalel Mebarki, , (2025-08-09), High-pressure insights into the material properties of cerium carbide, Electronic Materials, Vol:54, Issue:, pages:9016–9028, Springer Nature

This work presents a thorough analysis of the electronic, optical, and thermodynamic characteristics of ferromagnetic manganese selenide (MnSe) in both zinc-blende and rock-salt phases. Utilizing plane wave pseudo-potential calculations within the framework of spin-polarized density functional theory, our analysis offers a comprehensive evaluation. The calculated lattice parameters demonstrate a high level of concordance with available experimental data. Our findings indicate that MnSe compounds are semiconductors, as determined by their electronic band structures and density of states. Significant observations include the reduction in magnetic moments under increasing pressure, up to 10 GPa. Furthermore, we provide a detailed analysis of energy-dependent linear optical functions, including the complex dielectric function, complex refractive index, and reflectivity, and discuss their implications. Along with providing forecasts and in-depth discussions, our work clarifies the dependency of several thermodynamic variables on temperature and pressure for the compounds under investigation, including the bulk modulus, heat capacity, and thermal expansion coefficient.

Citation

SALIMA Saib , , (2025-05-28), Ab Initio Investigation of Physical Properties of Ferromagnetic Manganese Selenide in the Zinc-Blende and Rock-Salt Structures under Hydrostatic Pressure, Physics of the Solid State, Vol:67, Issue:9, pages:783–794, springer