Département sciences de la matière
Permanent URI for this collectionhttps://dspacee.univ-temouchent.edu.dz/handle/123456789/696
Browse
Recent Submissions
Item The replacement reflection of a transition metal 3d3 by 3d7 on 4a site in Mn2PtZ compounds: FP-LAPW approach(Indian J Phys, 2021) Hamli, M; Bensaid, D; Bouzouira, N; el Hannani, M Dine; Azzaz, Y; Doumi, BWe perform a first-principles calculation to understand the effect of the additional valence electron of the transition atom in Wyckoff position 4 a, on the electronic structure, magnetic and structural stability of the full Heusler Mn2PtZðZ ¼ VandCoÞ compound. L21, Xa and tetragonal structures are considered to verify the most stable phase. Within the framework of the plan Mn2PtZðZ ¼ VandCoÞ favored the ferromagnetic configuration in the L21 structure. The results show that the 63% and 91% spin polarization at the Fermi level for Mn2PtV and Mn2PtCo, respectively. The most contribution of the magnetic moment is due to the Mn atom, the total magnetic moments equal to 4:87lB and 9:012lB have been reported. To prove the half metallicity of our compound, we used the GGA ? U approach. Within the framework of this approach, the value gap in the minority spin band is 0.755 eV, more, the magnetic moment satisfying the SlaterPauling rule for the Mn2PtV compound. In addition, we give the two values of the curie temperatures for the two cubic structural phases. Finally, both full Heusler Mn2PtV and Mn2PtCo are a promising candidate for the use of future devices as spin-FETs and nonvolatile magnetic memoryItem Structural and Compositional Analyses of Spray Pyrolysis α‑Lanthanum Sulphide (α‑La2S3) Thin Films(Brazilian Journal of Physics, 2022) Tair, Sabrina; Nebatti Ech‑Chergui, Abdelkader; Kumar Mukherjee, Sanat; Boukhachem, Abdelwaheb; Kr. Singh, Rajan; Benaioun, Noureddine; Guezzoul, M’hamed; Chellali, Mohammed Reda; Zouke, Abdelhalim; Boussahoul, Fares; Driss‑Khodja, Kouider; Bouhalouane, AmranThis article describes the frst syringe pump spray pyrolysis synthesis of orthorhombic lanthanum sesquisulfde (α-La2S3) thin flms. Two precursors lanthanum nitrate La(NO3)3.6H2O and thiourea (SC(NH2)2) were used to develop these rare earth chalcogenides in two diferent “[S]:[La]” ratios of 5 and 11. The flms were developed on glass and silicon substrates. The microstructure, chemical composition, and optical properties of the (α-La2S3) flms were thoroughly characterized using X-ray difraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), microanalysis, scanning electron microscopy (SEM), FTIR spectroscopy, and UV–Vis spectrometry. Microstructural analyses showed that both synthesized flms had α-La2S3 structure and were polycrystalline. The morphology, vibration intensities, and grain sizes of the flms are afected by the amount of sulfde present. The XPS results give a qualitative description of La and S as well as an indication of their potential chemical state. Measurements of particle-induced X-ray emission (PIXE) provide information on the stoichiometric ratios of the constituent components in α-La2S3. The optical bandgap was calculated to be 3.39 eV and 3.45 eV, respectively, for ratios 5 and 11 of the disulfde content.Item First principle investigation of physical properties of MNiBi: (M = Sc, Y) half-Heusler compounds(Solid State Physics, 2022) Missoum, D; Bencherif, K; Bensaid, DWe have investigated the half Heusler compounds MNiBi (M=Sc, Y), using the framework of density functional theory DFT within the full potential linearized augmented plane wave (FP-LAPW) method and studied the structural, electronic, optical and elastic properties. The structural properties are predicted using the Generalized Gradient Approximation GGA and Local Density Approximation LDA, the calculations reveal that Lattice constants and other structural parameter are better matched in GGA approximation with experimental and theoretical result than LDA approximation. The calculated band structure and the density of states (DOS) with GGA, LDA and Tran and Blaha modified Becke-Johnson (TB-mBJ) exchange-correlation potentials, indicates a semiconducting nature with indirect narrow band gaps for both compounds ScNiBi and YNiBi, it shown from result that using (TB-mBJ) functionals is much more successful than the LDA and GGA approach in estimating bandgaps for our half Heusler ScNiBi and YNiBi. Optical properties of the compounds under investigation are also reported in this paper, high absorptivity are observed in the visible and ultraviolet region. The bulk modulus, shear modulus, young’s modulus, and other elastic constants are computed to discuss their elastic properties.Item Improvement electronic and magnetic properties of Cr impurity doped PbSe for optoelectronic devices applications: a first-principles proposal(THE EUROPEAN PHYSICAL JOURNAL B, 2021) Benkada, Amel; Habri, Salem; Bouzouira, Nour Eddine; Bensaid, Djillali; Hamli, Meryem; Bencherif, KaddourTo produce innovative spintronics components, we are now looking for ferromagnetic semiconductors at room temperature. The aim of this work is to study the electronic structures and the magnetic properties is to trigger ferromagnetism and to improve the band gap of PbSe The study of the electronic structure and the magnetic properties of diluted magnetic semiconductors (DMS) type IV–VI PbSe doped Cr is investigated in detail. Our results are as follows. We then calculated the sp-d exchange couplings between electrons (holes) of the conduction (valence) band and magnetic impurities. The topology of the band structure shows that our material is half metal, which has a direct gap in the minority channel due to the nature of sp–d coupling. The values of Nα ferromagnetic and Nβ antiferromagnetic obtained in the mean-field approximation are of the order of 0.551 and −0.445 eV respectively. The Thermoelectric Conversion Efficiency focuses on a single dimension parameter, the figure of merit ZT. We have seen that doping with Cr can also have a beneficial effect on thermal conductivity and consequently on ZT. This leads our material among the best compounds to thermoelectric applications.Item Heterogeneous advanced photo-fenton oxidation of phenolic aqueous solutions over iron-containing SBA-15 catalyst(MATEC Web of Conferences 5, 04033, 2013) Bailiche, Zohra;; Chérif-Aouali, Leila;; Royer, Sébastien; Bengueddach, Abdelkader; Fourmentin, Sophie; Siffert, StéphaneIron-containing SBA15 catalysts have been prepared following different synthesisroutes, direct synthesis by adjusting pH at 3 and 6 and with post synthesis procedure. Activity and stability of these materials were assessed on the photo-Fenton degradation of phenolic aqueous solutions by H2O2 using near UV irradiation (254 nm) at room temperature and initial neutral pH. Their catalytic performance was mentioned in terms of phenol and total organic carbon (TOC) conversions. Several complementary techniques, including XRD, Nitrogen sorption isotherms, UV visible, were used to evaluate the final structural and textural properties of calcined Fe-SBA15 materials. These materials show a high activity and stability of iron species.Item Nanocast ordered Mesoporous Ceria as Support for Highly Active Gold Catalysts for Toluene total Oxidation(International Journal of Chemistry, 2013-02) Bailiche, Zohra; Chérif-Aouali, Leila; Cousin, R; Royer, Sébastien; Bengueddach, Abdelkader; Pronier; Siffert, StéphaneAuCeO2 catalysts were synthesized using ceria prepared by the nanocasting pathway using the mesoporous SBA 15 silica as structure template and cerium nitrate as the CeO2 precursor via a solid –liquid route. These catalysts have been characterised by means: elemental analysis, H2- TPR, X-ray powder diffraction (XRD), BET surface area, diffuse reflectance ultra-violet visible spectroscopy (DR/UV-vis). Catalytic oxidation of toluene was investigated on gold/cerium oxide catalysts prepared by deposition-precipitation with several loading of gold (1wt%, 2wt%, and 4wt %). The presence of gold has been found to enhance the activity of cerium oxide to the deep oxidation of toluene, the degree of this effect depending on the gold loading. The activity for toluene deep oxidation of the AuCeO2 samples follows the order: 2wt%AuCeO2 ~ 1wt%AuCeO2 > 4wt%AuCeO2. The AuCeO2 catalysts are active at low temperature and selective for CO2 and H2O. The 1wt% AuCeO2 catalyst exhibits a long-term stability. The results we obtained point out that the catalytic activity of the gold/mesoporous ceria system towards the deep oxidation of toluene depends on the gold particle size and the amount of reducible surface oxygen species.Item Au/Fe2O3 Nanocatalysts for Toluene Oxidation as Model VOCs(TOPICS IN CHEMISTRY AND MATERIAL SCIENCE, Vol. 7 (2014) pp. 24–33, 2014) Bailiche, Zohra; Chérif-Aouali, Leila; Siffert, Stéphane; Royer, Sébastien; Bengueddach, AbdelkaderAu/ Fe2O3 catalysts were synthesized using iron oxide prepared by the nanocasting pathway using the mesoporous SBA-15 silica as structure template and iron nitrate as the Fe2O3 precursor via a solid–liquid route. These catalysts have been characterised by means: H2-TPR, X-ray powder diffraction (XRD), BET surface area. The gold particles sizes were investi gated by high resolution transmission electron microscopy (HRTEM). Catalytic oxidation of toluene was investigated on gold/iron oxide catalysts prepared by deposition-precipitation with different loading of gold (1 wt%, 2 wt%, and 4 wt%). The presence of gold has been found to enhance the activity of iron oxide towards the deep oxidation of toluene, the extent of this effect depending on the gold loading. The activity for toluene total oxidation of the Au/Fe2O3 samples follows this order: 2 wt% Au/Fe2O3 > 4 wt%Au/Fe2O3 > 1 wt%Au/Fe2O3. The Au/Fe2O3 catalysts are active at low temperature and selective for CO2 and H2O. The results we obtained point out that the catalytic activity of the gold/mesoporous iron system towards the deep oxidation of toluene depends on the gold particle size and/or the gold oxidation state and the reducibility of Au2O3 to AuOItem Heterogeneous Advanced Photo-Fenton Oxidation of Phenolic Aqueous Solutions over Iron-Containing SBA-15 Catalyst(2013-09-25) Bailiche, Zohra; Chérif-Aouali, Leila; Fourmentin, Sophie; Siffert, Stéphane; Bengueddach, Abdelkader; Royer, SébastienIron-containing SBA-15 catalysts have been prepared following different synthesis routes, direct synthesis by adjusting pH at 3 and 6 and with post synthesis procedure. Activity and stability of these materials were assessed on the photo-Fenton degradation of phenolic aqueous solutions by H2O2 using near ultraviolet irradiation (254 nm) at room temperature and initial neutral pH. Their catalytic performance was mentioned in terms of phenol and TOC (total organic carbon) conversions. Several complementary techniques, including X-ray, nitrogen sorption isotherms, UV (Ultraviolet) visible, were used to evaluate the final structural and textural properties of calcined Fe-SBA15 materials. These materials show a high activity and stability of iron species.Item Mesoporous Au/Fe2O3 catalyst for propargylamines synthesis via CH2Cl2 under visible light irradiation(Research on Chemical Intermediates (2022) 48:4119–4134, 2022-08-06) Berrichi, Amina; Bailiche, Zahra; Bachir, RedouaneThe AHA coupling of amines, haloalkane and alkynes under UV visible light was achieved with a higher yield in the presence of Au/Fe2O3. The catalyst was prepared by two methods using diferent gold content and then characterized by XRD, UV– vis, BET, TEM, ICP-OES and TPR spectroscopies. A comparative study of the ordi nary and photocatalytic conditions, showed that the UV visible light could activate the gold nanoparticles and lead to the formation of CH2Cl• and Cl• radicals through CH2Cl2 fragmentation. The propargylamine was aforded at low temperature and a short time using 2% Au/Fe2O3. The catalyst was stable for fve cycles with good photoactivity.Item Iron nanoparticles supported ordered mesoporous CeO2, an efcient catalyst for photo‑Fenton oxidation of phenol under irradiation(Research on Chemical Intermediates, 2023-03-09) Bailiche, Zahra; Berrichi, Amina; Bachir, RedouaneMesoporous CeO2-supported iron nanoparticles were prepared by the hard tem plate method with diferent iron loading. The catalysts were characterized by XRD, BET, UV–Vis, ICP, SEM–EDX, MET and TPR. The catalysts showed high activity and stability in the photo-Fenton oxidation of aqueous phenol solution using near ultraviolet irradiation (254 nm) at room temperature and neutral pH. The catalytic performance has been monitored in terms of aromatics and total organic carbon (TOC), and phenol conversion. Also, a comparative study between the CeO2 activity and catalysts was monitored which demonstrates that iron has a synergistic efect in the phenol photo-Fenton oxidation. Moreover, the formation of OH· and O2· radi cals accelerates the process by reducing Fe3+ to Fe2+ and Ce4+ to Ce3+ which leads to a total phenol oxidation at short time process. The total phenol conversion was obtained at 15 min with Fe/CeO2(60) and 20 min with Fe/CeO2(20)Item The replacement reflection of a transition metal 3d3 by 3d7 on 4a site in Mn2PtZ compounds: FP-LAPW approach(2021) Hamli, M; Bensaid, D; Bouzouira, N; el Hannani, M Dine; Azzaz, Y; Doumi, BWe perform a first-principles calculation to understand the effect of the additional valence electron of the transition atom in Wyckoff position 4 a, on the electronic structure, magnetic and structural stability of the full Heusler Mn2PtZðZ ¼ VandCoÞ compound. L21, Xa and tetragonal structures are considered to verify the most stable phase. Within the framework of the plan Mn2PtZðZ ¼ VandCoÞ favored the ferromagnetic configuration in the L21 structure. The results show that the 63% and 91% spin polarization at the Fermi level for Mn2PtV and Mn2PtCo, respectively. The most contribution of the magnetic moment is due to the Mn atom, the total magnetic moments equal to 4:87lB and 9:012lB have been reported. To prove the half metallicity of our compound, we used the GGA ? U approach. Within the framework of this approach, the value gap in the minority spin band is 0.755 eV, more, the magnetic moment satisfying the SlaterPauling rule for the Mn2PtV compound. In addition, we give the two values of the curie temperatures for the two cubic structural phases. Finally, both full Heusler Mn2PtV and Mn2PtCo are a promising candidate for the use of future devices as spin-FETs and nonvolatile magnetic memory.Item Structural and Compositional Analyses of Spray Pyrolysis α‑Lanthanum Sulphide (α‑La2S3) Thin Films(Brazilian Journal of Physics, 2022) Tair, Sabrina; Nebatti Ech‑Chergui, Abdelkader; Kumar Mukherjee, Sanat; Boukhachem, Abdelwaheb; Singh, Rajan Kr; Benaioun, Noureddine; Guezzou, M’hamed; Chellali, Mohammed Reda; Zoukel, Abdelhalim; Boussahoul, Fares; Driss‑Khodja, Kouider; Amrani, BouhalouaneThis article describes the frst syringe pump spray pyrolysis synthesis of orthorhombic lanthanum sesquisulfde (α-La2S3) thin flms. Two precursors lanthanum nitrate La(NO3)3.6H2O and thiourea (SC(NH2)2) were used to develop these rare earth chalcogenides in two diferent “[S]:[La]” ratios of 5 and 11. The flms were developed on glass and silicon substrates. The microstructure, chemical composition, and optical properties of the (α-La2S3) flms were thoroughly characterized using X-ray difraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), microanalysis, scanning electron microscopy (SEM), FTIR spectroscopy, and UV–Vis spectrometry. Microstructural analyses showed that both synthesized flms had α-La2S3 structure and were polycrystalline. The morphology, vibration intensities, and grain sizes of the flms are afected by the amount of sulfde present. The XPS results give a qualitative description of La and S as well as an indication of their potential chemical state. Measurements of particle-induced X-ray emission (PIXE) provide information on the stoichiometric ratios of the constituent components in α-La2S3. The optical bandgap was calculated to be 3.39 eV and 3.45 eV, respectively, for ratios 5 and 11 of the disulfde content.Item n-type SnS2 thin films spray-coated from transparent molecular ink as a non-toxic buffer layer for solar photovoltaics(iop publishing, 2022) Tair, Sabrina; Ghediya, Prashant R; Nebatti Ech-Chergui, Abdelkader; Guezzoul, M’hamed; Kumar Mukherjee, Sanat; Driss-Khodja, Kouider; Singh, Rajan; Ray, Jaymin; Amrani, BouhalouaneThis paper reports the effect of solvent evaporation temperature on spray-coated tin disulfide (SnS2) thin films from molecular ink. Thiourea and tin chloride were the key chemical reagents used for the synthesis of SnS2 transparent ink under atmospheric conditions. The structural and compositional properties of SnS2 thin films revealed formation of pristine hexagonal SnS2. The films are smooth, homogeneous resulting in band gaps ranging from 2 to 2.22 eV suited for a Cd-free alternative buffer layer for Cu-based multicomponent solar cells. Thermoelectric power measurement showed that tin disulfide films exhibit n-type conductivity. Activation energy estimated from temperature variation of electrical conductivity measurement varied from 40 to 90 mV. Our results suggest that ink-processed SnS2 can be used as a potential alternative for opto-electronic devices such as thin film solar cell and photodetector devices.Item Mechanical and morphological characterization of recycled HD-PE bio-composites based on alfa fibers and natural pozzolan(2022) Achour, Bouchra; Ziadi, Abdelkader; Belarbi, Lahcen; Mokaddem, Allel; Lousdad, AbdelkaderIn this research work, waste plastic bottle caps made of high-density polyethylene (HD-PE) were reincorporated as a matrix and reinforced by alfa short fibers and natural pozzolan particles. Using different weight percentages of both fillers of 5 wt% up to 30 wt%, three types of biocomposite materials have been produced; alfa short fibers/ HDPE, pozzolan particles/HDPE, and alfa fibers pozzolan/ HDPE. Specimens for each type of the biocomposites were prepared through the compression molding method. The objective of this study is to investigate the effect of different content of alfa short fibers and pozzolan particles on the mechanical and morphological properties of the recycled HDPE matrix. Tensile test results revealed an enhancement in the mechanical properties for the three types of the biocomposites, an increase in tensile strength reached the maximum of 3573 MPa plus an interesting improvement in Young’s modulus with a maximum value of 3696 MPa. The toughness of the neat recycled HD-PE decreased by 212% by adding the natural filler whereas the modulus of resilience exhibited an increase of 138% compared to the neat recycled HD-PE. Therefore, the good rheological behavior of these bio-composites makes it possible to produce competitive materials and allows the reduction of plastic waste in the environment.Item First principle investigation of physical properties of MNiBi: (M = Sc, Y) half-Heusler compounds(Revista Mexicana de F´ısica, 2022) Missoum, D.-E; Bencherif, K; Bensaid, DWe have investigated the half Heusler compounds MNiBi (M=Sc, Y), using the framework of density functional theory DFT within the full potential linearized augmented plane wave (FP-LAPW) method and studied the structural, electronic, optical and elastic properties. The structural properties are predicted using the Generalized Gradient Approximation GGA and Local Density Approximation LDA, the calculations reveal that Lattice constants and other structural parameter are better matched in GGA approximation with experimental and theoretical result than LDA approximation. The calculated band structure and the density of states (DOS) with GGA, LDA and Tran and Blaha modified Becke-Johnson (TB-mBJ) exchange-correlation potentials, indicates a semiconducting nature with indirect narrow band gaps for both compounds ScNiBi and YNiBi, it shown from result that using (TB-mBJ) functionals is much more successful than the LDA and GGA approach in estimating bandgaps for our half Heusler ScNiBi and YNiBi. Optical properties of the compounds under investigation are also reported in this paper, high absorptivity are observed in the visible and ultraviolet region. The bulk modulus, shear modulus, young’s modulus, and other elastic constants are computed to discuss their elastic properties.Item Exchange-correlation and spin-orbit coupling effects in 18-electrons transparent conductors half-Heusler: Ab-initio study(Computational Condensed Matter, 2022) Mellah, Djallal Eddine; Demmouche, KamelThe structural and electronic properties of a two non-oxide Transparent Conductors (TC’s), Ir-based halfHeusler XIrSb (X = Ti,Zr) are studied using DFT based on plane waves pseudo potential method. We examined two aspects: (i) the effect of the exchange–correlation (XC) approximation, namely: PBE, PBE+U and meta-GGA SCAN (The strongly constrained and appropriately normed); and (ii) the spin–orbit coupling (SOC) effects of the heavy metals on these compounds. We found that: (i) SCAN, similar to PBE+U, yields larger band gap compared to the PBE corresponding values for both compounds. SCAN gives a band gap about halfway between PBE and experiment or Hybrid-GGA. Similarly to PBE and PBE+U, SCAN shows the semiconducting behavior of the compounds with indirect band gap at the same locations in Brillouin Zone; (ii) spin–orbit coupling causes an important splitting in the valence band maximum (VBM) of order 0.44 eV and 0.58 eV for TiIrSb and ZrIrSb respectively leading to reduction of the band gap. Thus, the heavier is the X atom the larger is the SOC splitting. The VBM is dominated by 𝐽𝑒𝑓𝑓 = 3∕2 state. However, the splitting is almost negligible on the conduction band minimum (CBM). Therefore, SOC is crucial for predicting the band gap and reproducing correctly the electronic structure of these compounds.