Yazar "Ahmed, Emad M." seçeneğine göre listele

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    Examining Computationally the Physical Properties of Novel Lead-Free Eco-Friendly Chloroperovskites for Energy Applications
    (Springer, 2024) İrfan, Muhammad; Ahmed, Emad M.; Issa, Shams A. M.; Zakaly, Hesham M. H.
    This paper explores the various characteristics of the Li2Zr6MnCl15 chloroperovskites, including their structural, electronic, magnetic, optical, phononic, and thermoelectric properties. The computed phonon dispersions and formation energies provide strong evidence for the stability of this compound. Based on the analysis of magneto-electronic properties, it is observed that Li2Zr6MnCl15 demonstrates a semiconductor (2.2 eV Up/0.55 Dn) behaviour with a magnetic moment of 4.00 µB. Comprehensive analysis of optical properties involved intricate calculations of various parameters related to the behaviour of light, such as dielectric constants, refractive indices, reflectivity, extinction coefficients, electron energy loss, absorption coefficients, and optical conductivity functions up to 14.0 eV. The research was carried out in the temperature range of 50 to 800 K to determine the Seebeck coefficient, electrical conductivity, thermal conductivity, power factor (PF), Hall coefficient, and figure of merit for the investigated material, which showed great promise for use in thermoelectric devices, with PFs of about 7.5 × 104 W/K2ms, respectively. Using the application known as phy-x: PDS, All of the gamma radiation shielding parameters of Li2Zr6MnCl15 were determined, including mass attenuation coefficient (GMAC), linear attenuation coefficient (GLAC), half value (GHVL), mean free path (GMFP), the effective, effective atomic number (Zeff), and effective electron density (Neff). The research indicates that the GMAC and GLAC values for Li2Zr6MnCl15 fall as the photon energy rises, with a noteworthy increase near K-edge absorption owing to the photoelectric effect dominance at low energy. Both Zeff and Neff declined as the photon energy increased, with Zeff reducing from 25.56 to 25.27 and Neff decreasing from 3.22 × 1023 to 3.18 × 1023 electrons/g. Due to their robust absorption patterns and high PF, these compounds show great promise as thermoelectric and optoelectronic materials. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.
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    Fabrication, physical, structure characteristics, neutron and radiation shielding capacity of high-density neodymio-cadmium lead-borate glasses: Nd2O3/CdO/PbO/B2O3/Na2O
    (SPRINGER HEIDELBERG, 2022) Zakaly, Hesham M. H.; Tekin, Hüseyin Ozan; Issa, Shams A. M.; Henaish, A. M. A.; Ahmed, Emad M.; Rammah, Y. S.
    High-density glasses of neodymio-cadmium lead borate of chemical composition xNd(2)O(3)/20CdO/20PbO/(57-x)B2O3/3Na(2)O, where (0 (0Nd) <= x <= 5 (5Nd) wt%) have been fabricated by a melt quenching process. Physical, structure properties as well as gamma-radiation and neutron shielding effectiveness in wide photon energy range 0.015-15 MeV have been examined. The amorphous nature of xNd-glasses was confirmed, where there was a lack of their crystallinity. Density was gradually increased from 5.006 g/cm(3) for 0Nd-glass sample to 5.245 g/cm(3) for 5Nd-glass sample. In terms of the mass attenuation coefficient (MAC), introducing Nd3+ ions in the glass matrix has a direct constructive influence on the obtained values of MAC. Generally, the MAC trend follows the order (MAC)(5Nd) > (MAC)(4Nd) > (MAC)(3Nd) > (MAC)(2Nd) > (MAC)(1Nd) > (MAC)(0Nd). The linear attenuation coefficient (LAC) has a similar trend as MAC for all xNd-glasses. In terms of the half-value layer (T-1/2), the 5Nd-glasses possessed the minimum T-1/2 values (0.004 cm at 15 keV to 4.301 cm at 15 MeV). Therefore, the T-1/2 of the fabricated xNd-glasses has an inverse behavior of the MAC and LAC. Thus, (T-1/2)(0Nd) > (T-1/2)(1Nd) > (T-1/2)(2Nd) > (T-1/2)(3Nd) > (T-1/2)(4Nd) > (T-1/2)(5Nd). The effective atomic number (Z(eff)) parameter follows the order (Z(eff))(5Nd) > (Z(eff))(4Nd) > (Z(eff))(3Nd) > (Z(eff))(2Nd) > (Z(eff))(1Nd) > (Z(eff))(0Nd). In the energies preferred for radiation applications, 5Nd-glasses possess very low exposure (EBF) and energy absorption (EABF) buildup factor values. The fast neutron removal cross-section (FNRC) of the fabricated glasses is improved as the Nd3+ content increases in the glass matrix.
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    Mechanical properties as well as gamma-ray attenuation competence: a wide-ranging examination into Tb3+ doped boro-germanate- aluminiophosphate (BGAP) glasses
    (ELSEVIER, 2022) Zakaly, Hesham M. H.; Tekin, Hüseyin Ozan; ALMisned, Ghada; Ahmed, Emad M.; Issa, Shams A. M.; Ene, Antoaneta; Rammah, Y. S.
    The mechanical properties and radiation attenuation competence of Tb3 thorn ions doped borogermanate-aluminiophosphate (BGAP) glasses with codes Tb15, Tb20, Tb25, Tb30, Tb35, and Tb40 have been investigated. Bond compression model (B-C) and Phy-X/PSD software are used to achieve these aims. All elastic moduli were reduced with increasing the Tb2O3 content in the BGAP glasses. Values of bulk (KB -C) elastic modulus were possessed decreasing from 86.676 GPa for Tb15 glass sample to 80.205 GPa for Tb40 sample. The values of Young's (EB-C) modulus were found to decrease from 118.197 to 115.641 Gpa and Poisson's ratio (sB-C) of the BGAP glasses were reduced from 0.272 to 0.259. The highest values of linear (m) and mass (mm) attenuation coefficients were possessed for the Tb40 glass sample. Therefore, (mass, linear)Tb40 > (mass, linear)Tb35 > (mass, linear)Tb30 > (mass, linear)Tb25 > (mass, linear)Tb20 > (mass, linear)Tb15. Half value layer parameter (T1/2) and mean free path (l) of BGAP glasses were have a similar trend; (l, T1/2)Tb40 < (l, T1/2)Tb35 < (l, T1/2)Tb30 < (l, T1/2)Tb25 < (l, T1/2)Tb20 < (l, T1/2)Tb15. Exposure (EBF) and energy absorption (EABF) buildup factors have a similar attitude for all BGAP glasses. However, the minimum values of EBF and EABF were recorded for the Tb40 sample. Results confirm that Tb40 sample can be considered as superior for radiation shielding among all studied glasses.(c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
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    New eco-friendly lead-free double perovskites Rb2FeCdO6 driven semiconducting material for radiation shielding and energy applications: DFT plus U based nanoarchitectonics
    (Springer, 2024) Irfan, Muhammad; Ahmed, Emad M.; Issa, Shams A. M.; Zakaly, Hesham M. H.
    Double perovskites are emergent materials because of their exciting characteristics, such as their stable crystal structure. Thermoelectric, optical, structural, elastic, electrical, magnetic, and perovskite Rb2FeCdO6 properties are explored within the framework of spin-polarized density functional theory, all computations were carried out using the full-potential linear augmented plane-wave approach. The potential was applied using GGA with an extra onsite Coulomb parameter (GGA + U), including the Hubbard parameter. The phase stability calculation shows that Rb2FeCdO6 should remain stable in a ferromagnetic state and a cubic geometry (space group Fm-3 m). This Rb2FeCdO6 compound is mechanically and chemically stable, as confirmed by the computed formation energy, tolerance factor, and elastic constants. Poisson and Pugh's ratios were used to study ductile and brittle behaviour. Using the GGA + U methods, the results reveal that double perovskite has a semiconductor nature with a magnetic moment of 5.5 mu B, as determined by the magneto-electronic characteristics. The band structure calculations show the direct band gap of 2.2 eV (Up) and 1.8 eV (Dn) for Rb2FeCdO6 Double perovskites. The optical properties were also studied in detail, including complex dielectric constants, refractive indices, reflectivity, extinction coefficients, absorption coefficients, and optical conductivity functions up to 13.0 eV. Using the phy-x: PDS program, The mass attenuation coefficient (GMAC), linear attenuation coefficient (GLAC), half value (GHVL), mean free path (GMFP), effective, calculated atomic number (Zeff) were determined gamma radiation shielding properties of Rb2FeCdO6), and the effective electron density (Neff). The study shows that GMAC and GLAC values for Rb2FeCdO6 decrease with increasing photon energy, with a remarkable increase near K-edge absorption due to photoelectric effect dominance at low energy GHVL and GMFP increase with photon energy increases, indicating a decrease in photon interaction. We computed thermoelectric responses to evaluate potential and go into depth about the outcomes of the investigation. The Seebeck coefficient's positive and negative values classify double perovskites as exhibiting n and p-type semiconductors. These materials have high power factor values of 6.0 x 1011 Wm-1 K-2 s-1 and a figure of merit of 0.9, indicating good power conversion efficiency at high temperatures. Our results highlight the compound's potential for optoelectronic and thermoelectric devices.