Journal Articles

Permanent URI for this collection


Recent Submissions

Now showing 1 - 20 of 34
  • ItemOpen Access
    Properties of the double half-heusler alloy ScNbNi2Sn2 with respect to structural, electronic, optical, and thermoelectric aspects
    (2023) H. Mekki; H. Baaziz; Z. Charifi; A.E. Genç; S. Ugur; G. Ugur
    In the current work, the structural, electronic, thermoelectrics, and optical characteristics of the double half Heusler (DHH) ScNbNi2Sn2 compound are reported for the first time using density functional theory (DFT). The computed band structures show typical semiconductor behavior with an indirect bandgap (0.47 eV) using EV GGA approximation. We also investigated the optical properties such as the dielectric function, optical con ductivity, refractive index. Boltzmann’s semiclassical theory attempts to explain a simulation concept in the BoltzTrap software, and the findings were presented and analyzed in terms of electrical conductivity, electronic and lattice thermal conductivities, the Seebeck coefficient, and the Figure of merit over a 50 K–1000 K tem perature range. At room temperature, with a low magnitude of lattice thermal conductivity (κL) (5.30776 W/m. K) and a maximum value of the merit factor (ZT) is 0.64 at 900 K for ScNbNi2Sn2 compound is observed. These findings suggest that our material may be a viable option for use in high-temperature thermoelectric devices. We calculated (S, (σ /τ), (ke /τ)) along the x, y, and z axes utilizing the EV-GGA method. We found out that our compound is thermoelectrically anisotropic. We have also studied in EV-GGA the effect of the carrier concen tration on the Seebeck coefficnet at T = 600 K. The maximum value of S is 356.9905 μV/K with n = 3.04 × 1019Cm− 3 within GGA and EV-GGA respectively
  • ItemOpen Access
    First-principles calculations to investigate electronic structure and optical spectra of CdxZn1-xS ternary semiconductor alloys
    (Université de M'sila, 2023) S. Benlechheb; M. Boucenna; N. Bouarissa
    The structural parameters, electronic band structure and optical spectra of CdxZn1-xS (0 ≤ x ≤ 1) ternary semiconductor alloys are studied. The calculations are realized using the full potential linearized augmented plane wave method. The modified local density approximation (LDA) and generalized gradient approximation (GGA) have been used for describing the exchange-correlation potential. The obtained results for zinc-blende CdxZn1-xS ternary alloys show a general wellness with the data shown in the literature. An inspection of electronic band structure indicates that zinc-blende CdxZn1-xS are (Г→Г) direct band gap semiconductors (from x = 0 up to x = 1). A predominant ionic type of the chemical bonding in these materials has been indicated. The density of states shows various peaks in both valence and conduction localities proposing that an abundance of conditions is obtainable for occupation. The alloys affect the optical features of interest. The results obtained from the present work show that the zinc-blende CdxZn1-xS is a promettant material for photovoltaic device applications. Moreover, the alloy of interest can be used in different devices from visible to ultraviolet light
  • ItemOpen Access
    Gallium Antimonide Spherical Semiconductor Quantum Dots
    (université msila, 2022) Lynda Lakha; Fadila Mezrag; Nadir Bouarissa
    The quantum effects at the nano-metric level have been observed in a variety of confined structures, particularly in semiconductor quantum dots. In this contribution, the electronic and optical properties of GaSb spherical semiconductor quantum dots are investigated. For the calculations, the pseudo potential approach was employed. The size dependence of the energy gaps at Г, X and L points, the effective masses of electrons and heavy-holes, the refractive index, and the dielectric function for a studied GaSb spherical quantum dot are analyzed and discussed. When the degree of quantum confinement effect was changed by decreasing the radius of the spherical quantum dots, a striking charge in comparison to the bulk values has been obtained. Our results indicate that as the quantum dot radius is raised, most of properties rapidly decrease. This demonstrates an improvement in the mobility of the material. However, the refractive index and the dielectric constant are increased with increasing the radius of the nano-crystal. © 2022 The Electrochemical Society (“ECS”). Published on behalf of ECS by IOP Publishing Limited. [DOI: 10.1149/2162-8777/ ac942e]
  • ItemOpen Access
    A DFT-based model to the interpretation of DC conductivity in transition metals doped zinc phosphate glass
    (Université de M'sila, 2023) C Maghni; M Kharroubi
    Ternary zinc–sodium–phosphate glasses doped with transition metal of the composition Na2MxZn1-x P2O7(x = 0, 1, 2 and 5 mol %) (where M = Ni, Cu and Co) were prepared by the traditional quenching method. The ac conductivity measurements at different temperatures for the prepared glasses have been investigated, and the activation energy for dc conduction has been determined in each transition metal doped sample. The results showed that the evolution of the activation energy of the conductivity depends on the nature of the dopant ions. A model based on formal density functional theory concept in which the electrical charge exchanged between the transition-metal cations and the surrounding material surface is proposed. The outcome is a ‘‘simplified’’ formula which allows us to explain the evolution of the ionic dc conductivity activation energy as a function of the doped ion in interaction with the cation and the surface
  • ItemOpen Access
    Improvement of the reactivity of triethyl phosphate and structural behavior of hydroxyapatite versus the synthesis conditions by sol–gel route
    (Université de M'sila, 2022) Malika Merzougui; Fatima Zohra Mezahi; Achour Dakhouche; Djelel Kherifi; Foudil Sahnoune
    Hydroxyapatite (HA) is a biocompatible and bioactive material used as bone-substitute materials in both orthopedics and dentistry. This work is devoted to studying the synthesis of hydroxyapatite (HA) by sol–gel route using triethyl phosphate (TEP) and calcium nitrate tetrahydrate as calcium and phosphor precursors. In order to optimize the hydrolysis of TEP, each prepared solution was aged in a closed Teflon ® container. Several factors were tested in order to improve the synthesis conditions of well-crystallized HA. The effect of aging time (4 h, 16 h, and 24 h), aging temperature (25 °C, 50 °C, 70 °C, and 90 °C) of the prepared solutions, and the type of solvents (ethanol and/or distilled water) were tested. All dried gels were calcined at 700 °C for 1 h. The obtained results showed that the crystallinity degree of hydroxyapatite increases with aging time and temperature, which must not exceed 70 °C. When the prepared solutions were aged at 90 °C, the tri-calcium phosphate (TCP) was formed as a major phase and HA was present as a very minor phase. It was remarked that the aging of sols in a closed Teflon container ® leads to an important decrease of the aging time and temperature. It was found that 24 h and 70 °C are the optimal conditions for the synthesis of well-crystallized HA. Also, it was deduced that a sufficient amount of water was needed to hydrolyze the triethyl phosphate and consequently, to obtain a well-crystallized HA.
  • ItemOpen Access
    Effect of temperature and magnesia on phase transformation kinetics in stoichiometric and non-stoichiometric cordierite ceramics prepared from kaolinite precursors
    (université msila, 2022) Smail Lamara; Djaida Redaoui; • Foudil Sahnoune; • Nouari Saheb
    The influence of temperature and magnesia content on the formation of phases and their transformation kinetics in stoichiometric and non-stoichiometric cordierite ceramics prepared from Algerian kaolinite precursors was investigated. High-temperature X-ray diffraction was used to study the formation of phases and their transformations. Non-isothermal differential thermal analysis was used to determine kinetic parameters for the formation of l and a cordierite. Activation energies were calculated by Kissinger, Boswell, and Ozawa equations. The Augis–Bennett and Matusita equations were used to calculate the mode of crystallization (n) and dimension of growth (m) parameters, respectively. The synthesized materials showed similar phase transformations, which finally led to the formation of cordierite in stoichiometric kaolinite– magnesia mixture, and cordierite along with other phases in kaolinite–magnesia mixture containing excess magnesia. The activation energy for the formation of a cordierite was higher than that of l cordierite. Energies of formation of l and a cordierite phases in the non-stoichiometric samples were higher than those in the stoichiometric sample. The activation energy was less sensitive to the calculation method; however, it changed significantly with MgO content. Activation energies between 573 and 964 kJ mol-1 were obtained. Magnesia changed the crystallization mode and crystal growth dimension. The kinetic parameters n and m, for the formation of l or a cordierite, had values between 2 and 3.
  • ItemOpen Access
    Effect of octahedral cation on electronic, magnetic and optic properties of CoX2O4 (X = Cr, Mn and Fe) spinel compound
    (UNIVERSITE MSILA, 2022) N. Hetache; Z. Charifi; T. Ghellab; H. Baaziz; F. Soyalp
    The GGA+U approximation is used to compute the magnetic, structural, and optical and electronic properties of CoX2O4 (X = Cr, Mn and Fe) spineles. For these spineles, X has an effect on their behavior.The problem of the relationship between the relative forces of the exchange effect and the crystal field effect was investigated via a comprehensive examination of the densities of electronic states in order to get a better understanding of the electronic aspect of these compounds.It is only by the introduction of electron-electron interactions between magnetic cations that it is feasible to get the correct ground state. Changing the X cations causes a complete shift in the crystalline structure, which goes from cubic normal spinel for CoFe2O4 to tetragonal normal spinel for CoMn2O4 to inverse spinel for CoCr2O4.While our spineles exhibit considerable differences in their electronic behavior, an increase in the band gap from Fe to Mn and Cr compounds has been seen in our spineles. The occupancy of sub-lattices in the inverse phase of CoFe2O4 and the presence of severe structural distortion in the CoMn2O4 compound have a major impact on magnetic exchange interactions.In order to predict the trends of magnetic exchange couplings, it is necessary to analyze structural characteristics as well as electronic structures. Because the iron states in CoFe2O4 are tightly confined, this spinel differs significantly from the X cation states in the other two spinels, as shown by our observations. The change in X cations thus enables us to validate the trend in the characteristics of CoX2O4that has been observed.Prediction of optical characteristics is achievable, and we were able to compute a variety of optical parameters using this method. We've found that the value of  1 0 lowers as the band gap increases.
  • ItemOpen Access
    Influence of Cu-Doping on Linear and Nonlinear Optical Properties of High-Quality ZnO Thin Films Obtained by Spin-Coating Technique
    (Université de M'sila, 2022) Abdelkader Mohammedi
    To study the effect of Cu concentration on morphological, structural, linear and nonlinear optical properties, copper-doped ZnO thin films are grown by sol–gel/ spin-coating technique on the glass substrates. Scanning electron microscopy (SEM) images reveal that the surface morphology is homogeneous with good adhesion to the glass substrate. The energy dispersive X-ray spectroscopy (EDS) spectra confirm that Zn, O, and Cu elements are present in ZnO films. The X-ray diffraction (XRD) pattern of Cu-doped ZnO is dominated by (002) peak, indicating an upstanding ZnO nanorods array growing along the c-axis. The optical bandgap of Cu-doped ZnO thin films, calculated from optical transmission spectra, is found to decrease with the increase in copper concentration. The refractive index dispersion curve of ZnO films is subjected to the single-oscillator model. The optical dispersion parameters Eo, Ed, and n∞, the nonlinear refractive index, and nonlinear optical susceptibility are calculated and interpreted
  • ItemOpen Access
    Halide double perovskite Cs2AgInBr6 for photovoltaic’s applications: Optical properties and stability
    (Université de M'sila, 2022) Adel Menedjhi; Nadir Bouarissa; Salima Saib; Khaled Bouamama
    Theoretical calculations on halide double perovskite Cs2AgInBr6 electronic properties and optical spectra are carried out. The hybrid functional B3LYP calculations have been used indicating a 1.427 eV direct to band gap. The optical absorption coefficient has been determined showing a high-absorption (> 104 cm−1) within a large absorption range suggesting that the perovskite of interest-based solar cells may reach a good solar efficiency. Based on the refractive index spectrum, the Cs2AgInBr6 static refractive index is estimated and found to be 2.09. The stability, phonon spectrum, electron effective mass and absorption spectrum with solar spectrum at AM1.5 of Cs2AgInBr6 have been computed and verified
  • ItemOpen Access
    Thickness effect on the properties of Mn-doped ZnO thin films synthesis by sol-gel and comparison to first-principles calculations
    (Université de M'sila, 2022) Ammar Boukhari
    The current study investigates the effect of thickness on the structural, morphological, electronic, and optical properties of pure zinc oxide (ZnO) and 7% Mn-doped ZnO thin films, deposited by sol–gel spin coating method. All films exhibited a hexagonal wurtzite structure with a high preferential c-axis orientation. The surface morphology showed a good uniformity with cracks and wrinkles. The transmittance decreased with thickness. The bandgap energy was inversely varying with coating number. Photoluminescence spectra showed ultraviolet with strong and weak blue and weak green emission peaks. Density functional theory and Hubbard (DFT + U) method was then applied to study the structural, electronic, and optical properties of pure and 6.25% Mn-doped ZnO materials. A decrease in bandgap energy from pure to 6.25% Mn-doped ZnO material was shown using the DFT + U method. It also found that the Mn3d states were distributed far from Fermi level with a coexistence of both ionic and covalent nature bonds. A slight shift toward the lower energy was noticed for optical properties by Mn doping. The theoretical findings showed a similar behavior to those obtained by experiment.
  • ItemOpen Access
    First-principles calculation of magnetic, structural, dynamic, electronic, elastic, thermodynamic and thermoelectric properties of Co2ZrZ (Z = Al, Si) Heusler alloys
    (Université de M'sila, 2021) Sâad Essaoud
    Electronic, magnetic, dynamic, elastic, ‎thermodynamic, and thermoelectric properties for Co2-based full Heusler alloys are investigated theoretically. The full potential–linearized augmented plane wave (FP-LAPW) method within ‎density functional theory (DFT) incorporated on WIEN2k code is employed in ‎our calculation. Through this study, we found that the FM-L21 is the most magnetic-structure stable phase for both Co2ZrAl and Co2ZrSi compounds, as well as they, are dynamically stable where all the calculated of the optic and acoustic phonon frequencies have positive values. Band structure calculation demonstrated ‎that all compounds exhibit band gaps of about 0.88 and 1.54 eV using mBJ-GGA potentials for Co2ZrAl and Co2ZrSi in a localized minority spin channel (unlike the other ‎direction which appears a metallic behavior) with high spin polarization (100%) in its ground ‎state. Under high pressure, both compounds keep the same electronic behavior in both spins’ ‎channels with a little decreasing in gap energy, unlike the total magnetic moment which doesn’t ‎change. The semi-local Boltzmann ‎transport theory has been used to investigate thermoelectric properties and we found that both compounds exhibit a high Seebeck coefficient and high-power factor up to 1.25 mV/K for ‎Co2ZrSi. Also, the quasi-harmonic model has been applied to study the ‎temperature effect on heat capacities at ‎constant volume, in which entropy, Debye temperature and lattice ‎thermal conductivity are analyzed and ‎discussed. To get more information about the elastic ‎behavior; the elastic stability in the equilibrium state and under two pressures values (12 ‎GPa and 24 GPa) are found. The findings predicted the stability of these ‎compounds’ properties with and without pressure, which makes them candidate materials for ‎devices fabrication ‎in several areas such as spinotronic, thermoelectric, shape-memory and spin ‎filters.
  • ItemOpen Access
    Experimental and theoretical studies on structural, morphological, electronic, optical and magnetic properties of Zn1-xCuxO thin films
    (2021) Elhadj Benrezgua; Bahri Deghfel; Abdelhafid Mahroug; Muhamad Kamil Yaakob; Ammar Boukhari; Rabie Amari; Soorathep Kheawhom; Ahmad Azmin Mohamad
    Pure and copper-doped zinc oxide thin films at different contents x (Zn1-xCuxO; 0≤x ≤ 0.125) were synthesized by sol–gel spin coating process and investigated using various techniques. All samples exhibited a polycrystalline with wurtzite hexagonal phase, which wasn't altered and getting relaxed by Cu-doping. The grain size increased and changed its growth mode from c-axis growth to lateral one and the surface morphology was strongly influenced with increasing level of Cu doping. As x increased, the transparency of films was generally increased in the visible region and the band gap energy (Eg) presented a slight shrinking, indicating that the prepared films are suitable for use in opto-electronic applications. Ferromagnetic phase was adopted within density functional theory corrected by Hubbard method (DFT+LDA+U) to investigate the structural, electronic, magnetic and optical properties of pure and CZO structure. The closest Cu impurities gave the more stable configuration. Cu3d states were distributed around Fermi level inducing a major contribution to the magnetic moment. A mix of ionic and covalent bonding was remarked. DFT + LDA + U enhanced significantly the calculated Eg, which presented a narrowing with x. The imaginary part of the dielectric functions presented three main peaks and their static constants were slightly influenced by Cu doping.
  • ItemOpen Access
    Electronic structure, magnetic and optic properties of spinel compound NiFe2O4
    (Université de M'sila, 2021) K Bouferrache; Z Charifi; H Baaziz; A M Alsaad; Ahmad Telfah
    We report ab initio investigation of structural, electronic, magnetic and optical properties of the NiFe2O4 compound. Hubbard parameters are computed for both Ni and Fe atoms. Employing generalized gradient approximation (GGA) and GGA + U approximations and taking into consideration four possible types of atomic arrangements, we identify the most stable structural–magnetic configuration of the system. Interestingly, the inverse spinel NiFe2O4 compound is found to exhibit a ferrimagnetic structure. The ground state structural lattice parameters and the interatomic distances of spinel NiFe2O4 compound are computed. Furthermore, band structure calculations demonstrate that NiFe2O4 compound exhibits large band gaps in both spin configurations with a large magnetic moment. Energetically, ferrite nickel favors the inverse spinel phase in which Fe and Ni cations in either octahedral or tetrahedral sites adopt the high-spin configuration. We found that the energy of the normal spinel is higher than that of the inverse spinel, confirming that inverse spinel is the most stable structure of the NiFe2O4 compound. The optical behavior of the NiFe2O4 compound is characterized by calculating the real and imaginary part of the dielectric function, the absorption coefficients, the refractive index, the optical conductivity and the energy loss. Optimizing structural, electronic, magnetic and optical properties of this novel compound is crucial for exploring and utilizing it for modern device applications.
  • ItemOpen Access
    Sintering behaviour of fluorapatite–silicate composites produced from natural fluorapatite and quartz
    (Université de M'sila, 2021) D. Kherifi; H. Belhouchet; S. Ramesh; K.Y. Sara Lee; A. Kenzour; S. Djoualah; M.K; G. Abbas; Y.H. Wong; S. Ramesh
    In this work, the sintering behaviour of fluorapatite (FAp)–silicate composites prepared by mixing variable amounts of natural quartz (2.5 wt% to 20 wt%) and FAp was studied. The composites were pressureless sintered in air at temperatures from 1000 ◦C to 1350 ◦C. The effects of temperatures on the densification, phase formation, chemical bonding and Vickers hardness of the composites were evaluated. All the samples exhibited mixed phase, comprising FAp and francolite as the major constituents along with some minor phases of cristobalite, wollastonite, dicalcium silicate and/or whitlockite dependent on the quartz content and sintering temperature. The composite containing 2.5 wt% quartz exhibited the best sintering properties. The highest bulk density of 3 g/cm3 and a Vickers hardness of >4.2 GPa were obtained for the 2.5 wt% quartz–FAp composite when sintered at 1100 ◦C. The addition of quartz was found to alter the microstructure of the composites, where it exhibited a rod-like morphology when sintered at 1000 ◦C and a regular rounded grain structure when sintered at 1350 ◦C. A wetted grain surface was observed for composites containing high quartz content and was believed to be associated with a transient liquid phase sintering
  • ItemOpen Access
    Elastic-frustration-driven unusual magnetoelastic properties in a switchable core-shell spin-crossover nanostructure
    (Université de M'sila, 2021) Yogendra Singh; Hassane Oubouchou; Masamichi Nishino; Seiji Miyashita; Kamel Boukheddaden
    Spin-crossover (SCO) solids have been studied for their fascinating properties, exhibiting first-order phase transitions and macroscopic bistabilities, accompanied by significant magnetic, structural, and optical changes. These exceptional propertiesmake these materials promising for applications as high-density information storage and optical switches. Recently, the critical progress made in chemistry allowed the design of spin-crossover nanocomposites, combining the properties of two types of spin-crossover solids having different properties, like different lattice parameters, bulk moduli, transition temperatures, ligand fields, etc. In this paper, we consider a microscopic electroelastic description of a SCO nanostructure made of a SCO active core surrounded by a SCO active shell, for which we impose an unconventional elastic frustration at the core-shell interface. The detailed examination of the thermodynamic properties of such a nanocomposite, as a function of the lattice parameter misfit between the two constituents, revealed that the frustration causes unexpected behaviors on the thermal dependence of the average bond lengths, such as the emergence of two- or three-step spin transitions, with self-organization of the spin states in the plateau regions. These results highlight the nontrivial character of the magnetoelastic properties in switchable SCO nanoparticles.
  • ItemOpen Access
    Theoretical analysis of the structural, electronic, optical and thermodynamic properties of trigonal and hexagonal Cs3Sb2I9 compound
    (Université de M'sila, 2020) Saadi Berri
    The structural, electronic, optical and thermodynamic properties of Cs3Sb2I9 compound with 0-D dimer form (hexagonal SP; P63=mmc, no. 194) and the 2-D layered form (trigonal SP; P3 m1, no. 164) phases have been investigated and reported using both FP-LAPW and PP-PW methods. Besides, the thermodynamic properties of the materials of interest have been studied using the quasi-harmonic Debye model accommodating the lattice vibrations e ects. The obtained lattice parameters for dimer and layered phase reveal very good accord with experiment. The computed electronic band structures show that in the dimer phase the material of interest is an indirect band-gap (k{􀀀) semiconductor, whereas it is a direct band-gap (􀀀{􀀀) in the layered phase. The semiconducting material Cs3Sb2I9 of interest was found to be stable against volume change of 0 to +14%. Moreover, the optical properties of the material in question are also examined and discussed. The e ect of pressure and temperature on the studied properties is found to be highly e ective in tuning some of the macroscopic properties of the compound in question
  • ItemOpen Access
    A New Configuration of Vertically Connecting Solar Cells: Solar Tree
    (Université de M'sila, 2020) Anouar Bella Baci; Mohamed Salmi; Younes Menni; Samira Ghafourian; Milad Sadeghzadeh; Mohammad Ghalandari
    Copyright © 2020 Anouar Bella Baci et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Solar energy is a renewable type, clean, and inexhaustible which is sufficiently available on the Algerian territory. The energy received daily on a horizontal surface of 1 m2 is in the order of 5 kWh over almost the whole Algerian territory; the duration of sunshine surpasses 2000 hours annually and can reach 3900 hours on the highlands and the Sahara. The importance of this work is based on exploiting solar energy to produce electricity. This study is based on the experimental exploitation of solar energy using solar tree’s prototype suggestion. This new model is focused to replace the leaf of a tree by the solar cell, starting by examining the solar field and physical phenomenon related with it; the description of cell photovoltaic comes after; and finally, the dimension of the solar system and the experimental studies are virtually released in the University of M’sila. In this work, a prototype of new artificial solar tree is proposed experimentally by using material available in the local market: 25 solar panels, metal support, electrical queues, regulator, and battery. The results highlight a power improvement in the case of the proposed new model (solar tree) compared to the traditional one provided (solar panel), for the specified time range between 8 am and 2:30 pm. On the other hand, the traditional model values improve if the time dimension is extended from 2:30 pm to 6:00 pm. This is due to the temperature of the region and the presence of interstellar spaces between the cells of the solar tree.
  • ItemOpen Access
    Heat treatment and kinetics of precipitation of β-Mg17Al12 phase in AZ91 alloy
    (Université de M'sila, 2018) M. Fatmi; A. Djemli; A. Ouali; T. Chihi; M.A. Ghebouli; H. Belhouchet
    This study investigated the effect of aging on the precipitation and kinetics of second phase Mg17Al12 in AZ91 magnesium alloy (Mg-9 wt% Al-1 wt% Zn), using X-ray diffraction, microhardness measurements and differential scanning calorimetric analysis (DSC). With the last instrument, the all samples were heated from room temperature to 400 °C, at heating rates of 10–30 °C/min. The results were supplemented by measuring the average of activation energies, using isothermal treatments by Johnson–Mehl–Avrami (JMA) methods and by non-isothermal treatments using Ozawa, Boswell, Kissinger, Mahadevan, Augis and Bennett methods, were around 67.18 and 62.02 kJ/mol. The frequency factor k0 calculated by the isothermal treatment is equal to 1.24 109 s−1. In non-isothermal treatment, the numerical factor m and the Avrami parameter n is estimated to be approximately equal to 3 and 2.79 respectively. This value corresponding that the bulk nucleation with a constant number of nuclei was dominant in three-dimensional (polyhedron) controlled by interface reaction.
  • ItemOpen Access
    Exact analytical results for density profile in Fourier space and elastic scattering function of a rotating harmonically confined ultra-cold Fermi gas
    (Université de M'sila, 2018) S.Medjedel; K.Bencheikh
    In this paper, the system dealt with consisting of an ultra-cold neutral spin-polarized Fermi gas undergoing rotation (or in the so-called synthetic magnetic field) trapped by an anisotropic harmonic potential in a two and three-dimensional space at zero temperature. Using the so-called Bloch propagator as a tool, we derive exact closed-form expressions for particle density in Fourier space which are valid for an arbitrary particle number confined by a two and three-dimensional rotating anisotropic harmonic trap. Numerical illustrations and discussions are presented. The results can be easily generalized at finite temperatures. The crossover from two-dimensional to the one-dimensional regime is shown to be reflected in the shape of the density distribution in Fourier space at very fast rotating velocity (or at strong synthetic magnetic field). In addition, an exact analytical expression of the elastic scattering factor is found, a quantity of interest used to probe the spatial distribution of the quantum gases
  • ItemOpen Access
    Electro-vibrational Ising-type model for spin crossover in binuclear molecules
    (Université de M'sila, 2019) A Metatla; H Latelli
    spin crossover in binuclear molecule is investigated using an Ising-type model, including the intramolecular vibrations. The spin transition curve of [Fe(bt)(NCS)2]2bpym complex which presents a two-step transition plateau is well described by the above model. We show that the equilibrium low-spin/high-spin temperature Teq is independent of the vibration frequencies of the intermediate state (HS–LS or LS–HS) xLHS. In addition, a large values of LS–LS state vibration frequencies xLLS lead to an evident two-step transition plateau.