Thin films of highly pure (99.999%) Tellurium was prepared by high vacuum technique (5*10-5torr), on glass substrates .Thin films have thickness 0.6m was evaporated by thermal evaporation technique. The film deposited was annealed for one hour in vacuum of (5*10-4torr) at 373 and 423 K. Structural and electrical properties of the films are studies. The x-ray diffraction of the film represents a poly-crystalline nature in room temperature and annealed film but all films having different grain sizes. The d.c. electrical properties have been studied at low and at relatively high temperatures and show that the conductivity decreases with increasing temperature at all range of temperature. Two types of conduction mechanisms were found to dominate in the measured temperature range
In this work, the optical properties of Cu2S with different thickness
(1400, 2400, 4400) Ǻ have been prepared by chemical spray pyrolys
is method onto clean glass substrate heated at 283 oC ±2. The effect
of thickness on the optical properties of Cu2S has been studied. It
was found that the optical properties of the electronic transitions on
fundamental absorption edge were direct allowed and the value of the
optical energy gap of Cu2S (Eg) for direct transition decreased from
(2.4-2.1) eV with increasing of the thickness from (1400 - 4400)Ǻ
respectively. Also it was found that the absorption coefficient is
increased with increasing of thicknesses. The optical constants such<
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Thin films of CuPc of various thicknesses (150,300 and 450) nm have been deposited using pulsed laser deposition technique at room temperature. The study showed that the spectra of the optical absorption of the thin films of the CuPc are two bands of absorption one in the visible region at about 635 nm, referred to as Q-band, and the second in ultra-violet region where B-band is located at 330 nm. CuPc thin films were found to have direct band gap with values around (1.81 and 3.14 (eV respectively. The vibrational studies were carried out using Fourier transform infrared spectroscopy (FT-IR). Finally, From open and closed aperture Z-scan data non-linear absorption coefficient and non-linear refractive index have been calculated res
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In this study, the effect of grafting with magnesium (Mg) ratios (0.1, 0.3, 0.5) on the structural and optical properties of cadmium oxide films (CdO) was studied, as these films were prepared on glass bases using the method of pulse laser deposition (PLD). The crystallization nature of the prepared membranes was examined by X-ray diffraction technique (XRD), which showed that the synthesis of the prepared membranes is polycrystalline, and (AFM) images also showed that the increased deformation with magnesium led to an increase in the grain size ratio and a decrease in surface roughness, as well as the absorption coefficient was calculated. And the optical energy gap for the prepared membranes, where it was found that the absorption coef
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The Influence of annealing temperature on the optical properties of (CuInSe2) thin films was studied. Thermal evaporation in vacuum technique has been used for films deposited on glass substrates, these films were annealed in vacuum at (100C°, 200C°) for (2 hours). The optical properties were studied in the range (300-900) nm. The obtained results revealed a reduction in energy band gap with annealing temperature . optical parameters such as reflectance, refractive index, extinction coefficient, real and imaginary parts of the dielectric constant, skin depth and optical conductivity are investigated before and after annealing. It was found that all these parameters were affected by annealing temperature.
Thin films of ZnO nano crystalline doped with different concentrations (0, 6, 9, 12, and 18 )wt. % of copper were deposited on a glass substrate via pulsed laser deposition method (PLD). The properties of ZnO: Cu thin-nanofilms have been studied by absorbing UV-VIS, X-ray diffraction (XRD) and atomic force microscopes (AFM). UV-VIS spectroscopy was used to determine the type and value of the optical energy gap, while X-ray diffraction was used to examine the structure and determine the size of the crystals. Atomic force microscopes were used to study the surface formation of precipitated materials. The UV-VIS spectroscopy was used to determine the type and value of the optical energy gap.
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The Invar effect in 3D transition metal such as Ni and Mn, were prepared on a series composition of binary Ni1-xMnx system with x=0.3, 0.5, 0.8 by using powder metallurgy technique. In this work, the characterization of structural and thermal properties have been investigated experimentally by X-ray diffraction, thermal expansion coefficient and vibrating sample magnetometer (VSM) techniques. The results show that anonymously negative thermal expansion coefficient are changeable in the structure. The results were explained due to the instability relation between magnetic spins with lattice distortion on some of ferromagnetic metals.
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CuInSe2 (CIS)thin films have been prepared by use vacuum thermal evaporation technique, of 750 nm thickness, with rate of deposition 1.8±0.1 nm/sec on glass substrate at room temperature and pressure (10-5) mbar. Heat treatment has been carried out in the range (400-600) K for all samples. The optical properties of the CIS thin films are been studied such as (absorption coefficient, refractive index, extinction coefficient, real and imaginary dielectric constant)by determined using Measurement absorption and transmission spectra. Results showed that through the optical constants we can made to control it is wide applications as an optoelectronic devices and photovoltaic applications.
Density Functional Theory (DFT) with B3LYP hybrid exchange-correlation functional and 3-21G basis set and semi-empirical methods (PM3) were used to calculate the energies (total energy, binding energy (Eb), molecular orbital energy (EHOMO-ELUMO), heat of formation (?Hf)) and vibrational spectra for some Tellurium (IV) compounds containing cycloctadienyl group which can use as ligands with some transition metals or essential metals of periodic table at optimized geometrical structures.
In the oil industry, the processing of vacuum residue has an important economic and environmental benefit. This work aims to produce industrial petroleum coke with light fuel fractions (gasoline, kerosene , gas oil) as the main product and de asphalted oil (DAO) as a side production from treatment secondary product matter of vacuum residue. Vacuum residue was produced from the bottom of vacuum distillation unit of the crude oil. Experimentally, the study investigated the effect of the thermal conversion process on (vacuum residue) as a raw material at temperature reaches to 500 °C, pressure 20 atm. and residence time for about 3 hours. The first step of this treatment is constructing a carbon steel batch re
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The CdSe pure films and doping with Cu (0.5, 1.5, 2.5, 4.0wt%) of thickness 0.9μm have been prepared by thermal evaporation technique on glass substrate. Annealing for all the prepared films have been achieved at 523K in vacuum to get good properties of the films. The effect of Cu concentration on some of the electrical properties such as D.C conductivity and Hall effect has been studied.
It has been found that the increase in Cu concentration caused increase in d.c conductivity for pure CdSe 3.75×10-4(Ω.cm)-1 at room temperatures to maximum value of 0.769(Ω.cm)-1 for 4wt%Cu.All films have shown two activation energies, where these value decreases with increasing doping ratio. The maximum value of activation energy was (0.319)eV f