Physique

Permanent URI for this collectionhttps://dspacee.univ-temouchent.edu.dz/handle/123456789/749

Browse

Now showing 1 - 20 of 56

Systèmes Énergétiques Innovants : L'Utilisation de l'Énergie Solaire pour l'Élevage de Volaille
(2025) HADDOUCHE, Ahmed Amine; RACHEDI, Samia
The title "Innovative Energy Systems: Using Solar Energy for Poultry Farming" discusses the integration of solar technologies into poultry farming practices. This abstract could explore how solar energy is used to power heating, lighting, and ventilation systems on poultry farms, thereby reducing energy costs and carbon footprints. The study could also address the economic and environmental benefits of these systems, while highlighting specific innovations, such as solar greenhouses or photovoltaic panels that improve animal.
DFT Investigation Of physical properties Of ABH3 (A = K, Li, Rb ; B = Ca, Sr) perovskite hybrids materials
(2025) TAHROUR, Abderrahime; ELAHMAR, Mohamed Hichem
In this study, we conducted a comprehensive investigation based on density functional theory (DFT) to explore the structural, electronic, and mechanical properties of hybrid perovskite compounds with the formula ABH3, where A = K, Li, and B = Ca. The optimized crystal structures show that these compounds adopt a stable perovskite phase with cubic symmetry. Electronic band structure analysis reveals a semiconducting behavior, with an indirect band gap in the range of 1 to 2 eV depending on the nature of the alkali cation. This behavior suggests a strong potential for applications in optoelectronics and energy storage. The calculated elastic constants confirm the mechanical stability of these materials and allow determining their ductile or brittle behavior. These results show that ABH3 compounds (A = K, Li; B = Ca) are promising candidates for the development of new hydrogen-based semiconductor materials.
First-principles prediction of Mn-based Perovskite-type hydrides AMnH3 (X = K, Li) for hydrogen storage applications
(2025) BENAYAD, Houari; Dr.EELAHMAR, Mohamed Hichem
The objective of this work is to study, by ab initio calculations, the physical properties of manganese-based perovskite hydrides (XMnH3) (X = K, Li). These materials could be used in hydrogen storage due to their diverse physical and chemical characteristics and cubic crystal structure. The ability of perovskite compounds to adsorb hydrogen is one of the main characteristics qualifying them for hydrogen storage .The physical properties of Mn-based compounds. Perovskite hydrides XMnH3 (X = K, Li), including electronic and magnetic properties, are presented. The parameters are calculated to be 3.89 Å and 3.38 Å for KMnH3 and LiMnH3, respectively. Electronics and Magnetics The properties of both materials indicate that they are semi-metallic and ferromagnetic in nature, with strong spin polarization and therefore have a greater capacity for polarizing and storing incident electromagnetic radiation. This suggests that they are a superior option for hydrogen storage applications.
Étude et réalisation de Couches Minces biosourcés Hydrophobes et Anti-Poussière pour les surfaces vitrées des panneaux solaires photovoltaïques
(2025) KADABENABDALLAH, Chaimaa; FEKIH, Zakia
This study falls within the scope of applied research at the intersection of advanced materials, environmental sustainability, and surface functionalization. It contributes to the development of clean technologies by exploring environmentally responsible solutions based on renewable natural resources in the field of functional coatings. The adopted approach aims to balance technical performance with adherence to green chemistry principles, targeting high-value applications in energy systems and material protection. The research focuses on the development and characterization of bio-based thin films exhibiting hydrophobic and dust-repellent properties. Natural components, including essential oils, green solvents, and biopolymers, were selected for their ecological compatibility, surface functionality, and optical stability. The coatings were applied using the dip-coating method—a simple, reproducible technique capable of producing uniform and homogeneous films. 80 Characterization techniques included UV-Visible spectrophotometry to assess optical transparency and Atomic Force Microscopy (AFM) for surface morphology analysis. The results revealed good light transmittance, controlled surface roughness, and satisfactory hydrophobic performance. This work proposes a viable ecological alternative to conventional coatings for dusty environments and opens promising prospects for optimizing bio-sourced materials in photovoltaic applications.
Structure cristalline et propriétés optiques de double pérovskite inorganique à base d’alcalin et d’indium
(2025) Elmeguenni, Noura; NEBATTI ECH, CHERGUI Abdelkader
This thesis is devoted to the theoretical study of the structural and optical properties of the inorganic compound Rb2LiInI6. This material, which belongs to the family of double perovskites halides, isattracting growing interest due to its potential applications in optoelectronics. The analysis was carried out using density functional theory (DFT), as implemented in the Wien2k code, based on the full potential augmented linearized plane wave (FP-LAPW) method. The calculations were used to determine the ground-state crystal structure and to extract the lattice parameters, formation energy, and the stability of the compound. In parallel, the study of optical properties revealed interesting behavior in terms of dielectric response, absorption function, and refractive index. These results provide a better understanding of the potential of Rb2LiInI6 in the field of optoelectronic devices, particularly as a candidate for photovoltaic cells or ultraviolet detectors.
Les propriétés structurales, électroniques et magnétiques des matériaux monopnictogen à base de samarium SmX (X=N, P, As, Sb et Bi)
(2025) Khelfoun, Lina Insaf; Belkadi, Amina
In this study, we conducted an in-depth investigation of the structural, magnetic, and electronic properties of SmX compounds (X = N, P, As, Sb, Bi), a class of rare-earth pnictides, using the full-potential linearized augmented plane wave (FPLAPW) method as implemented in the WIEN2k code. Our calculations show that the NaCl-type structure is the most stable phase for all compounds. The equilibrium parameters obtained using the GGA- PBEsol approximation is in good agreement with available experimental and theoretical data. The bulk modulus analysis indicates decreasing stiffness with increasing pnictogen atomic number, with SmN being the least compressible and SmBi the most. A pressure-induced phase transition from NaCl to CsCl structure was identified for all compounds, with critical transition pressures decreasing from SmP to SmBi. Additionally, all SmX compounds exhibit a ferromagnetic ground state with a magnetic moment close to 5 μB, consistent with the presence of localized 4f electrons in samarium. The electronic structure, studied using both GGA and the modified Becke-Johnson (mBJ-GGA) potential, reveals that SmN exhibits half-metallic behavior, with a larger direct band gap obtained using mBJ-GGA. SmP and SmAs also show half-metallic character with moderate indirect gaps, while SmSb and SmBi transition from semi-metallic to half-metallic behavior when using mBJ-GGA instead of GGA. The band structure and density of states analysis highlight the dominant role of samarium 4f electrons near the Fermi level, especially in the majority-spin channel, leading to half-metallicity—metallic for majority spin and semiconducting for minority spin. Furthermore, strong hybridization between the pnictogen p- states and Sm f- and d-states contributes to the complex electronic behavior of these materials.
ÉTUDE DES PROPRIETES PHYSIQUES DE LA DOUBLE PEROVSKITE EN PHASE CUBIQUE
(2025) DERNI, Abdel hakim Yassine; ELAHMAR, Mohamed Hichem
The first principle calculations were used to study the structural, electronic and magnetic properties of the alloy Ba2EuSbO6 using full-potential lirearized augmented plane waves (FP-LAPW) method based on the density functional theory (DFT). The potential of exchange and correlation is treated by the generalized gradient approximation (GGA-PBE) for two states, non-magnetic state (NM) and ferromagnetic state (FM).The results obtained show that the compound is stable in the ferromagnetic state (FM). The results obtained for the density of states and band structure revealed that our compound has a metallic character and is a good candidate for spintronics applications. The study of magnetic properties, we found that the major contributions of the total magnetizations are localized at Eu atoms.
Étude Ab-initio des propriétés physiques et calcul phonons des alliages Heusler
(2025) ZEIDOUNI, Rahma
In this work, we presented a theoretical study of the structural, electronic, magnetic, and dynamic properties of the Heusler alloy Cu2MnP. The main objective of this study is to investigate several physical parameters such as the equilibrium lattice parameter, bulk modulus, density of states, electronic band structure, magnetic moment, and dynamic properties through phonon analysis. Calculations were performed using the FP-LAPW method, as implemented in the WIEN2k code, within the general framework of density functional theory (DFT), employing the generalized gradient approximation (GGA). The phonon dispersion curves were analyzed to assess the dynamic stability of the crystal structure and to evaluate vibrational interactions. The results indicate that Cu2MnP exhibits a ferromagnetic metallic character but shows dynamic instability, suggesting that the considered structure may be metastable or subject to a structural phase transition at low temperatures.
L’effet photothermique Des Nanoparticules d’or dans le traitement d’une tumeur
(2023) Nougrara, Mohammed Seddik; BENSAFA, Imad Khaled
Effet des impuretés sur les propriétés physique de SmO
(2023) BOUBASLA, ILHAM; Bensaid, Djillal
The interest of this study is to deepen the study of the structural, electronic and magnetic properties of Samarium Oxide doped with the transition elements Mn , Fe , Co within the framework of the DFT The calculations were carried out using the calculations of first principle of the theory of the functional of the density and the potential of exchange and correlation was treated by approximation GGA-PBEsol. The lattice constant for compounds Sm0.75 X0.25 O (X= Mn, Fe and Co) decreases when passing through Mn Fe Co while the modulus of atoms while the bulk modulus increases. The spin states prove that the compounds Sm0.75 Co0.25 O exhibit a half-metallic character while Sm0.75 Fe 0.25O and Sm0.75 Mn0.25 O exhibits a metallic character We therefore conclude that Sm0.75 X 0.25O can be included in the field of spintronics
Effet Du Dopage Par Ag Sur La Dégradation Photocatalytique Des Films Minces D'oxyde De Nickel (NiO) Préparés Par Procédé Spray- Pyrolyse
(2023) Belkheir, Fatima; Nebatti ech-chergui, Abdelkader
This thesis focuses on the fabrication and characterization of Ag-doped NiO thin films for the photodegradation of dyes. The films were prepared using the spray pyrolysis technique on glassn substrates and subjected to various characterization techniques. X-ray diffraction (XRD) analysis confirmed the cubic structure of both NiO and Ag-doped NiO films. Energy-dispersive spectroscopy (EDX) was employed to determine the atomic concentrations of Ni, O, and Ag in the films. The thin films exhibited an average transmittance of approximately 51% in the visible region of the spectrum. Significant absorption was observed at 364 nm, corresponding to the optical bandgap of NiO. Ag doping had a minimal impact on the film's transmittance, and no systematic variation in Ag concentration was observed. The bandgap energy was measured between 4.09 and 3.92 eV, decreasing with a 2% Ag content and increasing to 4.01 eV with 4% Ag. The photodegradation of methylene blue dye was investigated using the NiO and Ag-doped NiO thin films. Results demonstrated rapid dye degradation within the first 40 minutes, followed by a gradual decrease in degradation efficiency. The addition of Ag significantly enhanced the degradation efficiency, particularly with a 4% Ag concentration. This thesis successfully presents the fabrication of Ag-doped NiO thin films for dye photodegradation. The results suggest the promising potential of these thin films in the field of dye degradation, offering new prospects for applications in this domain.
Etude Elaboration et caractérisation de couches minces de La-SnS2
(2023) BEGHALEM, YACINE; Mohamdi, Mohamed Walid
In the current study, we report on the synthesis and in-depth characterizations of La (2%, 4%)-doped SnS2 thin films prepared by means of a spray-coated approach from clear molecular ink for photodegradation application. The effects of La doping on the structural, chemical and morphological properties of the thin films were investigated by range of suited techniques. Our results showed that the pure SnS2 films are grown in the SnS2 phase with (101) preferred planes while a second phase of Sn2S3 appears by introducing La doping. La détection des éléments Sn, S et La dans les résultats de l'analyse EDX confirme la formation de SnS2 et la présence du dopage au La. The infrared spectroscopy analysis confirms the presence of Sn-S bonds in the La-doped SnS2 thin films. Finally, the films are found to exhibit a band gap ranging from 2 eV to 2.22 eV.
Synthèse et étude des propriétés optiques de Couches d’Oxydes métalliques et Applications photovoltaiques
(2023) ADADA, Mama; BOUCHENAK KHELLADI, Nesrine
Studies carried out on transparent and conductive oxides TCO have attracted the attention of many researchers because of their various applications in the industry of microelectronics, mechanics, optoelectronics, surface treatment and especially in photovoltaics, etc. thanks to their double property, electrical conductivity and transparency in the visible. Metal oxide materials deposited in thin layers such as TiO2 and ZnO have been known for a long time. Zinc oxide (ZnO) is a material belonging to the family of transparent conductive oxides (TCO). The non-toxicity and abundance on earth of its components make it an ideal candidate as a transparent electrical contact for thin-film solar cells of amorphous and/or microcrystalline silicon. The fundamental objective of our research work is to optimize the basic component optical properties of ZnO/PVP-based solar cells and this according to an elaborate process, by sol-gel route of ZnO/PVP layers under different experimental conditions. To determine the structure characterize the deposits obtained and characterize their optical properties to optimize the parameters we produce our solar cells. Thanks to the framework agreement signed in 2022 between the Belhadj Bouchaib University and the Abou Bekr Belkaïd University of Tlemcen, the chemical preparations and optical characterizations of the thin layers deposited by the spin coating method are carried out at the level of the Materials and Renewable Energies Unit (URMER) from the University of Tlemcen.
L'effet des impuretés magnétiques sur les propriétés électroniques et magnétiques de l’Oxide d’Europium
(2021) Benkhelifa, Djihene; Bensiad, Djillali
Notre travail consiste à étudier les propriétés structurales, électroniques et magnétiques du oxyde de l’europium (EuO) dopé au impuretés de chrome (Cr), en utilisant la méthode des ondes planes augmentées à potentiel complet plus les orbitales localisés ( FP-LAPW + Lo), implantée dans le code Wien2K, où le potentiel d’échange et corrélation a été traité par l’approximation du gradient généralisé (GGA-PBEsol) plus le Potentiel d'interaction de Coulomb (U), au sein de la théorie fonctionnelle de la densité (DFT). Les propriétés structurales à savoir le paramètre de maille, le module de compressibilité et sa dérivée sont en bon accord avec les résultats trouvés à littératures. L'analyse des structures de bandes, densité d'états(DOS), les interactions d'échange et de moments magnétiques révèle que les tous composées Eu0.75Cr0.25O, Eu0.5Cr0.5O et Eu0.25Cr0.75O peuvent présenter un caractère demi-métallique ferromagnétique
Études AB-INITIO des propriétés : Structurales et Electronique et Magnétique De pérovskite SrTiO3
(2021) NOUN, MOUNIR; Dine el hannani, Mohammed
Ce travail propose que le matériau titanate de strontium (SrTiO3) soit l'un des oxydes ABO3 de type pérovskite les plus étudiés en raison de son importance technique importante. Nous utilisons le calcul ab-initio basé sur la méthode FP-LMTO (Full Linear Orbital Muffin Potential) sous forme de théorie fonctionnelle de la densité (DFT),et utilisons l'approximation de la densité locale (LDA) et l'approximation de la densité de spin locale (LSDA) Implémenté dans le programme LmtART pour déterminer la structure, les propriétés électroniques de la pérovskite SrTiO3. Les propriétés structurelles, à savoir les paramètres de grille, le module de compression et ses dérivés, sont très cohérents avec les autres résultats disponibles. Les résultats de la structure de bande et de la densité d'états (DOS) montrent des semi-conducteurs et montrent en outre que SrTiO3 a un gap indirect (M-). Nous avons expliqué les résultats de la simulation et les avons comparés aux résultats expérimentaux et théoriques existants.
Etudes de premier principe des Propriétés Structurales, électroniques et Optique des matériaux FluoroPérovskite BaXF3 (X=K, Rb )
(2021) Fekih, Hadjer; Harmel, Meriem
Dans ce mémoire nous présentons des calculs du premier principe de l'énergie totale sur les propriétés structurales, électroniques et optiques des composés BaXF3 (X=K, Rb) et qui sont des matériaux de structures pérovskites. Pour cela nous avons appliqués une étude théorique en utilisant la méthode des ondes planes linéairement augmentées à potentiel total (FP-LAPW) basée sur la théorie de la fonctionnelle de la densité (DFT). Le potentiel d’échange-corrélation est traité par l’approximation de la densité locale (LDA) et l’approximation du gradient généralisé (GGA). Les propriétés structurales telles que le paramètre du réseau, le module de compressibilité et sa dérivée sont en bon accord avec les données disponibles. Les résultats obtenus pour la structure de bandes et les densités d’états (DOS) montrent que les composés BaKF3 et BaRbF3 ont un gap direct (Γ-Γ). La densité de charge montre que la liaison entre les éléments qui constituent ces matériaux est principalement ionique. Les propriétés optiques telles que les parties réelles et imaginaires de la fonction diélectrique ε(ω), l'indice de réfraction n(ω) et le coefficient d'extinction k(ω) sont calculées.
Etude de premier principe des propriétés physiques des matériaux XBi ( X=La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er) dans la structure de type NaCl et pour les trois états NM,FM et AFM.
(2021) BELGACEM, Sabrine; TOUIA, Amina
Les propriétés structurales, électroniques et magnétiques des alliages XBi (X= La, Ce, Pr, Nd ,Sm ,Tb ,Gd ,Dy, Ho, Er) à structure faces cubiques centrées (NaCl) et pour les trois états non magnétique (NM), ferromagnétique (FM) et antiferromagnétique (AFM) ont été présentés en utilisant un calcul de premier principe. Nous avons appliqué la méthode des ondes planes augmentées et linéarisées à potentiel maximal (FP-LAPW) basé sur la théorie fonctionnelle de la densité (DFT) et implémentée dans le package Wien2k. En plus, l'approximation du gradient généralisée (GGA-PBE) à été utilisée pour décrire le potentiel d'échange-corrélation. Les résultats obtenus pour la densité d'états et la structure de la bande révèlent que nos composés ont un caractère métallique. Les propriétés structurelles montrent que l’état le plus stable pour nos binaires XBi (X=Ce, Nd) est l’état antiferromagnétique et pour les binaires XBi (X=Pr, Sm, Tb, Gd, Dy Ho, Er) est l’état ferromagnétique et enfin pour le LaBi est l’état non magnétique.
Etude du premier principe des propriétés structurales, électroniques, magnétique et la pression de transition des composés Erbium Monopnictides ErX (X=N, P, As, Sb et Bi)
(2021) BENICHOU, Maroua; Belkadi, Amina
In this work we have chosen a first principle calculations in the aim to study the structural, electronic and magnetic properties of rare earth types ErX (X = N, P, As, Sb and Bi). The method used was full potential augmented plane wave FPLAPW implemented in the WIEN2K code, the treatment of the exchange correlation potential was with the GGA approximation. The results prove that ErX are ferromagnetic materials and they crystallize in the NaCl structure, which is in good agreement with the available theoretical data. The calculation of the transition pressure has shown that the ErX (N, P, As and Sb) transit at high pressures from the NaCl structure to the CsCl structure while the ErBi transit at a very low pressure. In this work the ErN was found almost semi-metallic with the GGA and semi- metallic with the mBJ-GGA which is not the case for the other ErX (X = P, As, Sb and Bi) that they had a metallic character using GGA and a semi-metallic character using mBJ-GGA. We have also determined the density of state (DOS) and the magnetic moment of ErX.
Propriétés Structurales et Electroniques des Alliages a Changement de Phase GeSbTe
(2021) Bounouira, Amina; Benyahia, Karima
Etude des propriétés structurales et électroniques de l’alliage à changement de phase de Ge2Sb2Te5 par des calculs de premier principe. Nous avons appliqué l’approche des ondes planes (PW) et du pseudo-potentiel dans le cadre de la théorie de la fonctionnelle de densité (DFT) en utilisant l’approximation du gradient généralisé (GGA) et l’approximation du gradient généralisé de Perdew-Burke-Ernzerhof (PBE). Les résultats des propriétés structurales et électroniques sont en bon accord avec les résultats expérimentaux.
A first principales study of the half mettalic behaviour at hight temperature on oxide-perovskite BaMnO3 comound
(2021) BEL GHORZI, Zohra; LAHMER, mohamed Hichem
Des calculs de premiers principes basés sur la théorie fonctionnelle de la densité ont été utilisés pour étudier les propriétés structurales, électroniques ,magnétiques et thermoélectrique de pérovskite BaMnO3. Les calculs ont été effectués par la méthode des ondes planes augmentées linéarisées avec un gradient généralisé (GGA) et GGA+ U pour les fonctions d'échange et de corrélation. Les propriétés électroniques montrent que BaMnO3 présente un caractère semi-métallique complet pour les deux approximations GGA avec un moment magnétique entier, alors que pour BaMnO3,présentent un comportement métallique . la réponse thermoélectrique est calculée à l'aide du code BoltzTrap basé sur la théorie semi-classique de Boltzmann

Browse

Recent Submissions