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Your search keyword '"A. El-Denglawey"' showing total 310 results
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310 results on '"A. El-Denglawey"'

1. Prediction of mechanical and radiation parameters of glasses with high Bi2O3 concentration

Author

A. El-Denglawey, Hesham M.H. Zakaly, K. Alshammari, Shams A.M. Issa, H.O. Tekin, Waheed S. AbuShanab, and Yasser B. Saddeek

Subjects
Bismuthate based glasses, XCOM database, FLUKA code, Physics, QC1-999
Abstract

This study aims to perform multidirectional characterizations on nuclear shielding efficiencies on some bismuth-based glasses. Accordingly, the γattenuation coefficients for xBi2O3-(75-x)B2O3–25Li2O (x = 0, 10, 20, 30, 40, 50, 60 the 70 mol%) were widely evaluated using simulations and theoretical methods. Linear attenuation coefficient (LAC) of the glasses was obtained by the Monte Carlo general-purpose simulation code FLUKA and compared with the XCOM database up to 15 MeV. Moreover, LAC values have been utilized to evaluate related parameters like mass attenuation coefficient (MAC), total molecular cross-section (σt), total atomic cross-section (σa), half-value layer (HVL), total electronic cross-section (σe), mean free path (MFP), effective atomic number (Zeff), and effective electron density (Neff). The results noted that the XCOM and FLUKA data of the shielding parameters are in great agreement. Relatively higher density (5.818 g/cm3), greater LAC, MAC, Zeff, and lower HVL, MFP values are achieved for 70Bi2O3-5B2O3–25Li2O glass. Accordingly, this glass sample is a better gamma shield.

Published
2021
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2. The effect of thickness on the structural and optical properties of nano Ge-Te-Cu films

Author

A. El-Denglawey, M.M. Makhlouf, and M. Dongol

Subjects
Physics, QC1-999
Abstract

Quartz was used as a substrate to hold different film thicknesses of Ge0.15Te0.78Cu0.07 within range 100–500 nm prepared by thermal evaporation technique. Films are still amorphous up to 200 nm and turn to more ordered nano polycrystalline one by ascending the values of film thickness up to 500 nm. Films turn to crystalline phase due to annealing. The relation of resistance and temperature shows phase transformation. Optical constants; refractive index, n absorption coefficient, α single-oscillator energy, Eo dispersion energy, Ed lattice dielectric constant, εL infinite wavelength dielectric constant, ε∞ the ratio of the carrier concentration to the effective mass, N/m∗ optical conductivity, σ and energy loss function, ELF show decreasing values with thickness up to 200 nm followed by ascending values within range 200–500 nm. It is concluded that the thickness range 100–200 nm introduces more disordered films while 200–500 nm introduces more ordered one. Keywords: GeTeCu alloys, Structural properties, Optical properties, Thickness, Nano materials, Phase change memory

Published
2018
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3. Aging effect on the structure and optical properties of nano Cu2S films

Author

H.A. Alburaih and A. El-Denglawey

Subjects
Physics, QC1-999
Abstract

The amorphous nature is the dominant state of the as deposited Cu2S films. Films were aged for 3, 6 and 12 months. The aged films of 12 months are poly crystalline within nano scale. (102), (110), (103) and (112) were the preferred orientations of 12 months of aging. The calculated crystallite sizes were 13, 29, 33 and 54 nm respectively. The optical gap is direct; it increases with the increasing of aging time as well as oscillation energy and constant A. Refractive index, the infinity dielectric constant, the lattice dielectric constant the real and the imaginary part of the dielectric constant, the ratio of carrier concentration to the effective mass, the dispersion energy are decreasing with the increasing of aging time. Optical conductivity and energy loss function were studied; both decrease by the increasing of aging time. Keywords: Aging, Structure of nano crystals and nano particles, Optical constants, Optical properties of thin films, Amorphous semiconductors, Glasses

Published
2017
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4. A comprehensive first principles calculations on (Ba0.82K0.18)(Bi0.53Pb0.47)O3 single-cubic-perovskite superconductor

Author

Rubel, Mirza H. K., Mitro, Sujon Kumar, Hossain, Khandaker Monower, Rahaman, Md. Mijanur, Hossain, M. Khalid, Hossain, Jaker, Mondal, B. K., Ahmed, Istiak, Islam, A. K. M. A., and El-Denglawey, A.

Subjects
Condensed Matter - Superconductivity, Physics - Applied Physics
Abstract

In this present study, the pseudopotential plane-wave (PP-PW) pathway in the scheme of density functional theory (DFT) is utilized to investigate the various physical properties on (Ba0.82K0.18)(Bi0.53Pb0.47)O3 (BKBPO) single perovskite superconductor. We have analyzed elastic constants and moduli at zero and elevated pressures (up to 25 GPa) as well. We also have investigated the anisotropic nature incorporating both the theoretical indices and graphical representations in 2D and 3D dimensions, which reveals a high level of anisotropy. The flatness of the energy bands near EF is a sign of Van-Hf singularity that might increase the electron pairing and origination of high-TC superconductivity. The computed band structure exhibits its metallic characteristics is confirmed by band overlapping. A band of DOS is formed for the strong hybridization of the constituent elements. The orbital electrons of O-2p contribute most dominantly at EF in contrast to all orbital electrons. The orbital electrons at the EF are higher from both the partial density of states and charge density mapping investigation. The coexistence of the electron and hole-like Fermi sheets exhibits the multi-band nature of BKBPO. On the other hand, Fermi surfaces with flat faces promote transport features and Fermi surface nesting as well. The calculated value of the electron-phonon coupling constant ({\lambda} = 1.46) is slightly lower than the isostructural superconductor, which indicates that the studied BKBPO can be treated as a strongly coupled superconductor similar to the reported isostructural perovskite superconductors. Furthermore, the thermodynamic properties have been evaluated and analyzed at elevated temperature and pressure by using harmonic Debye approximation (QHDA)., Comment: 20 pages, 7 figures, 6 tables

Published
2021
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