mahrous.r.ahmed

Mahrous R Ahmed

Professor -

Faculty of science

Address: Physics Department - Science Faculty - Sohag University - Egypt

17

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2021 | Keywords Ising model, Monte Carlo,
Monte Carlo study of the effect of charge ordering on the electrical and magnetic properties of half-doped manganites
The Monte Carlo Antiferromagnetic Ising model was used to study the electrical properties and magnetoresistance of manganese oxides due to the charge ordering phase occurring at half doping, _x = 0.5_. The half-doped manganites have an insulator antiferromagnetic ground state. The internal energy, specific heat, resistivity, the magneto-resistance and magnetization have been investigated with different applied magnetic fields. Our simulation ... Read more

2021 | Keywords Thin films,
Influence of different types of substrates on the physical properties of CdSe films
Cadmium Selenide, CdSe, thin films deposited on different substrate types; FTO/glass,/glass, and ITO/glass substrates were produced by thermal evaporation method in the room temperature. The influence of different types of substrates on the structural, optical and electrical properties of the films was studied by X-ray diffraction and absorption photo spectroscopy respectively. X-ray diffractions revealed that all the CdSe films have ... Read more

2021 | Keywords solar cell,
Experimental and theoretical studies of (CdS)1-x (ZnS)x thin-films for second generation CdS/CdTe solar cells
The current work focused on studying the optical and structural properties of (CdS)1-x (ZnS)x thin films fabricated by thermal vacuum evaporation approach. The evaporation was implemented at room temperature from bulk samples synthesis by sintering approach. The energy gap, index of refraction, extinction coefficient and absorption coefficient were estimated from the experiment and employed in our theoretical model to estimate ... Read more

2021 | Keywords Hexaferrites,
Dielectric, magnetic and structural properties of Co-doped hexaferrite synthesized by microwave digestion system
Co substitution in hexaferrites Sr1−xCoxFe12O19 compounds with doping values x = 0.0, 0.075, 0.15, 0.225 and 0.30 were prepared using microwave digestion system. Structural, morphological, magnetic and dialectic properties were investigated. X-ray diffraction pattern proved a hexagonal phase (SrFe12O19) existing as a main phase for all samples. The lattice parameters, crystallites size and other parameters such as microstrain and direct ... Read more

2020 | Keywords solar cell,
Theoretical Studies of Thin-Film Solar Cells based on CdTe with different Window-Layers
The effect of using different types of window layer on the performance of thin-film solar cell based on CdTe was studied. Here, we investigated Cadmium Sulphide (CdS), Zinc Selenide (ZnSe) and Zinc Sulphide (ZnS) as window layer candidates. The calculations of short-circuit current density, internal quantum efficacy, external quantum efficient and the solar cell efficacy were achieved based on the ... Read more

2020 | Keywords optical properties,
Optical and structure properties of CdTe/CdS films under influence of both CdCl2 heat treatment and (O2 + Ar) atmosphere
Thin films of CdTe/CdS were prepared using the thermal evaporation technique with pressure 2 × 10−5 mbar on substrate from glass. The thickness of CdCl2 layer around 150 nm was deposited making as-deposited CdTe/CdS films. The films covered by cadmium chloride (CdCl2) layer were annealed in atmosphere of (O2 + Ar) at different temperatures of 400 °C, 450 °C and ... Read more

2020 | Keywords Thin films,
Effect of RF power of Al2O3 target on the physical properties of aluminum‑doped zinc oxide films
In this report, we investigate the optical and electrical properties of aluminum zinc oxide (AZO) thin films using magnetron sputtering method in preparing the thin films and spectrophotometer to measure the optical characteristics. The X-ray diffraction (XRD) patterns of the films are found to have amorphous structure. The optical band gap _E_g, refractive index _n_, electronic polarizability, carrier concentration _N_c, ... Read more

2019 | Keywords Magnetocaloric,
Use of Magnetocaloric Material for Magnetic Refrigeration System: A Review
Our daily need to cooling system is grown up. The used cooling systems are the source of the harmful changes in the global climate. And so, we need to search a new alternate cooling systems applying environmentally friendly technology that may help in decreasing the pollutions in our world. The progress in materials science allows to use some materials for ... Read more

2017 | Keywords solar cell,
Improvement of the performance of thin-film CdS/PbS solar cells using low-cost ZnO-based alloys as front electrode
All thin film solar cells require the use of transparent conductive electrodes such as indium tin oxide (ITO) due to its unique combination of transparency, high conductivity, durability, and favourable surface properties. Indium, however, is a rare and expensive metal; proposed large-area installations of photovoltaic (PV) cells will add further strain to global indium supply. Transparent conductive materials that are ... Read more

2016 | Keywords Magneto caloric effect,
Electrical and magnetic transport in Strontium doped Europium Ferrimanganites
Eu0.65Sr0.35Fe_x_Mn1−_x_O3 (_x_=0.1, 0.3 and 0.5) has been prepared using a standard solid state reaction method. The under-investigation compounds is found to crystallize in a single-phase orthorhombic structure in the _P__bnm_ space group (62). The adiabatic polaron electronic transfer was obtained for all samples and the activation energy of _x_=0.1 sample is equal to 1.013 meV and slightly increase at _x_=0.3 ... Read more