In this research, the structural and optical properties were studied for Bi2O3 and Bi2O3: Al thin films with different doping ratios ( 1, 2, 3 ) % , which were prepared by thermal evaporation technique under vacuum , with thickness ( 450 ± 20 ) nm deposited on glass substrates at room temperature ( 300 ) K , Structural measurements by ( XRD) techniques demonstrated that all samples prepared have polycrystalline structure with tetragonal structure and a preferred orientation [ 201 ] the optical measurement shows that all films have a direct energy gap , and in general decrease with the increase of doping ratio except ratio ( 3% Al ) . The optical constant such as absorption coefficient , extinction coefficient , refractive index real and imaginary parts of the dielectric constant and optical conductivity were calculated before and after doping with the range of wave lengths ( 300 - 1100 ) nm .
The effect of the annealing on the optical transmission , absorp tion coefficient,
dielectric constants (ε
r
),( ε
i
) ,Skin depth and the optical ener gy gap of (ZnO)x(CdO)1-x thin
films with (x=0.05) deposited on preheated glass substrates at a temperature of (450 C°) by
chemical pyrolysis technique were performed . These f ilms show direct allowed inter band
transition that influenced by annealing at ( 450 C°) for two hours . And it also found that the
optical ener gy gap has been increased fro m about (2.50 eV) before annealing to about (2.65
eV) after annealing , fro m the analysis of the absorp tion and transmission sp ectra in the
wavelength range (380-900nm) . The results show t
We have studied the synthesis environment of ambient pressure silica aerogels influence on their resulting morphological and optical properties. Transparent nanoporous silica aerogel was synthesized at ambient pressure using tetraethylorthosilicate precursor via a sol-gel process. Effect of drying control chemical additives and catalyst on physical properties was investigated. Trimethylchlorolsilane was employed as a hydrophobic reagent in the surface modification process. All aerogel samples were prepared utilizing a subcritical procedure under reactant pH fixed at 8.3, using just ammonium hydroxide or together with ammonium fluoride as catalyst. The effects catalyst types as well as drying control chemical additives on the physical pro
... Show MoreZinc oxide (ZnO) transparent thin films with different oxygen flow rates (0.5, 1.0, and 1.5)Litter/min. were prepared by thermal evaporation technique on glass substrate at a temperature of 200℃ with rate (10±2)nm sec-1, The crystallinity and structure of these films were analyzed by X-ray diffraction (XRD). It exhibits a polycrystalline hexagonal wurtzite structure and the preferred orientation along (002) plane. The Optical properties of ZnO were determined through the optical transmission method using ulta violet–Visible spectrophotometer with in wave length (300-1100)nm. The optical transmittance of the ZnO films increases from 75% to 85% with increase flow rate of O2, and the optical band gap of ZnO
... Show MoreThin films of the blended solution of NiPc/C60 are fabricated using spin-coating method for three different ratios (100/1, 100/10 and 100/100) according to the weight. The films are deposited on to glass substrates and treated with several annealing temperatures (373, 423 and 473)K. The structure and surface morphology of the as-deposited and annealed films using x-ray diffraction and AFM was studied and exhibited a change and enhanced crystallization and surface morphology caused by changes in heat treatment temperatures. Investigation of X-ray diffraction patterns of NiPc/C60 indicated that it have polymorphism structure, i.e. mix between amorphous and polycrystalline structure. when heat treatment temperatures ch
... Show MoreThe electrical properties of the AlNiCo thin films with thickness (1000oA) deposited on glass substrates using Ion – Beam sputtering (IBS) technique under vacuum <10-6 torr have been studied . Also it studied the effect of annealing temperature from this films , It is found that the effective energy decrease with increase of temperature and the conductivity decrease with increase temperature 323oK but after this degree the conductivity increasing .
Solutions of dyes Rhodamine 6G (Rh6G) and Coumarin480(C480) were prepared at five concentrations (1x10-3, 5x10-4, 1x10-4, 5x10-5 and1x10-5) mol/l, the mixing was stirred to obtain on a homogenous solution, the(poly methyl-methacrylate) (PMMA) was solved by chloroform solvent with certain ratio, afterward (PMMA+Rh6G) and (PMMA+C480) thin films were prepared by casting method on glass block which has substrate with dimensions (7.5 x2.5)cm2, the prepared samples were left in dark place at room temperature for 24 hours to obtain uniform and homogenous thin films. UV-VIS absorption spectra, transmission spectra and fluorescence spectra were done to measure linear refractive index and linear absorption coefficient. The nonlinear optical proper
... Show MoreSuperconducting thin films of Bi1.6Pb0.4Sr2Ca2Cu2.2Zn0.8O10 system were prepared by depositing the film onto silicon (111) substrate by pulsed laser deposition. Annealing treatment and superconducting properties were investigated by XRD and four probe resistivity measurement. The analysis reveals the evolution of the minor phase of the films 2212 phase to 2223 phase, when the film was annealed at 820 °C. Also the films have superconducting behavior with transition temperature ≥90K.
Copper tin sulfide (Cu2SnS3) thin films have been grown on glass
substrate with different thicknesses (500, 750 and 1000) nm by flash
thermal evaporation method after prepare its alloy from their
elements with high purity. The as-deposited films were annealed at
473 K for 1h. Compositional analysis was done using Energy
dispersive spectroscopy (EDS). The microstructure of CTS powder
examined by SEM and found that the large crystal grains are shown
clearly in images. XRD investigation revealed that the alloy was
polycrystalline nature and has cubic structure with preferred
orientation along (111) plane, while as deposited films of different
thickness have amorphous structure and converted to polycrystalline
Polyaniline (PANI) polymer was successfully prepared by the chemical oxidation method at 0 oC. Polyaniline-nano grapheme (GN) powder nanocomposites were prepared by the addition of GN with different weight ratios (0.1, 1, 5, and 10 g wt. %) during the polymerization of PANI. It was found that the polymerization reaction of poly-aniline was exothermic. The effect of adding nano-graphene powder during polymerization process on the time and temperature of the reaction was studied. The resulting polymer was diagnosed using several methods, including Fourier transform infrared spectroscopy (FT-IR) and UV-VIS spectrophotometry. The results of FTIR demonstrated a shift to higher wave numbers in the peaks of nanocomposites, due
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