A5073563992- Phase-change materials and chalcogenides
- Solid-state spectroscopy and crystallography
- Chalcogenide Semiconductor Thin Films
- Statistical Mechanics and Entropy
- Theoretical and Computational Physics
- Thermodynamic properties of mixtures
- Glass properties and applications
- Spectroscopy and Quantum Chemical Studies
- Material Dynamics and Properties
- ZnO doping and properties
- Semiconductor materials and devices
- Gas Sensing Nanomaterials and Sensors
- Complex Systems and Time Series Analysis
- Neural Networks and Applications
- Conducting polymers and applications
- Metallic Glasses and Amorphous Alloys
- Copper-based nanomaterials and applications
- Quantum Dots Synthesis And Properties
- Advancements in Semiconductor Devices and Circuit Design
- Molecular Sensors and Ion Detection
- Analytical Chemistry and Sensors
- Semiconductor materials and interfaces
- Earthquake Detection and Analysis
Beni-Suef University
1998-2019
Cairo University
1990-2004
Ain Shams University
1986
The effect of Tl addition on the electrical and thermal properties binary chalcogenide semiconductor As2Se3 has been studied in homogeneous glass-forming region. thallium ternary system (As2Se3)1-xTlx, where x varies between 0 0.7, tends to decrease glass transition melting temperatures increase DC conductivity amorphous phase. activation energy for crystallisation solid phase is found vary 0.44 1.34 eV a way which similar compositional dependence gap there discontinuity at concentrations...
Se0.9In0.1 samples were prepared from their highly pure constituents, by ice-water quenching the melts. Structural characterization using XRD and DTA has revealed a stable phase consisting of some crystalline clusters embedded in glassy matrix with single glass transition (Tg) at temperature 320 K, an onset exothermic crystallization peak 361 melting endotherm point 473 K. The dc (ohmic contact region) ac (50 Hz–80 kHz) conductivities measured under vacuum as function (from T < Tg down to...
Abstract Structural phase transitions in the lipid-like bilayer material [(CH2)12(NH3)2]CuCl4 have been observed using differential thermal scanning. The compound shows an irreversible thermochromic transition at ˜ 465 K and three reversible T 1 = 433 ± 4 2 411 3 358 K. 350 is ascribed to chain melting. other two correspond crystalline transformation. Phase (IV) T3 2K (III) T2 (II) T1 4K (I) Dielectric permittivity studied as a function of temperature range 300-440 frequency, (60 Hz-100...
Amorphous chalcogenide composition As4Se4Te2 is prepared by the conveniential quenching technique. The separate isothermal annealing or γ irradiation not effected physical properties of sample. samples are subjected to simultaneous at temperature 150°C and γ-quanta irradiation. dark dc conductivity decreases with increasing time γ-irradiation exposure. At dose 1.1 M rad, starts have metallic-like character. Also a crossover from Efros–Shklovskii percolation mechanism conduction Mott...
Abstract This work deals with the determination of characteristics Coulomb gap (CG) in density states (DOS) vicinity Fermi level, from analysis temperature dependence dc conductivity range (1.5 K–300 K) germanium, disordered by large fluences fast reactor neutrons. From application, percolation theory and variable hopping (VRH) under effect interaction localized carriers, localization radius is found to be 49.2 Å. The dielectric constants samples are determined. (© 2004 WILEY‐VCH Verlag GmbH...
Abstract The interaction of iodine with donor bases such as neutral red (NR) and 1, 10 -phenanthroline (Ph) have been studied spectrophotometrically in C2H5OH. results indicate the formation 2:3 charge transfer complexes type (base)23I2. Mass, Raman 1H NMR spectra recorded for each complex. I3 − I2 species are observed these complexes. In addition, d.c. conductivity is measured range (300–400) K°. energy gap ionic conduction has calculated. process thought to involve iodide between polyanions.
The temperature dependence of the dc conductivity and thermoelectric power was determined for five different amorphous chalcogenide Se–Ge–Te films, with Ge = 3.0–22 at.%, Se 0–97 at.% Te at.%. films were prepared by thermal evaporation GeSe4, GeTe4 GeSe2Te2 quenched bulk materials. Values activation energy calculated from both electrical showed a decrease increasing content in Se–Ge as well replacement films. results an Anderson transition, showing insulating behaviour on Ge–Se side to...
Abstract This work deals with the determination of magnitude fractal dimension, from analysis temperature dependence dc conductivity in range 1.5–300 K germanium, disordered by large fluences fast reactor neutrons, radiation defect concentration making it an insulator near metal–insulator transition. From reduced activation energy method and percolation theory hopping conductivity, dielectric constants samples are calculated. The localization radius is determined. obtained dimensions found...
D. C. conductivity () measured in the temperature (T) range (300 K- 1.7K) for p-Type Ge irradiated with quanta and /or large fluencies of reactor neutrons. The obtained results reveal that, activation energies different mechanisms are found E1> E2 > E3 o> 1> 2. Also, Meyer- Neldel Rule (MNR) is applicable conduction mechanisms. As well As, hopping values Energy (HMNR) each mechanism. Mott variable (VRH) = f (T-0.25), Efros Sholovskii Percolation mechanism (ESPMC) (T-0.5) conduction....
Structural phase transitions in the lipid-like bilayer material [(CH2)12(NH3)2]CuCl4 have been observed using differential thermal scanning. The compound shows an irreversible thermochromic transition at ˜ 465 K and three reversible T 1 = 433 ± 4 2 411 3 358 K. 350 is ascribed to chain melting. other two correspond crystalline transformation. Phase (IV) T3 2K (III) T2 (II) T1 4K (I) Dielectric permittivity studied as a function of temperature range 300-440 frequency, (60 Hz-100 kHz). It...
Abstract This work deals with the determination of magnitude fractal dimension, from analysis temperature dependence dc conductivity in range 1.5–300 K germanium, disordered by large fluences fast reactor neutrons, radiation defect concentration making it an insulator near metal–insulator transition. From reduced activation energy method and percolation theory hopping conductivity, dielectric constants samples are calculated. The localization radius is determined. obtained dimensions found...