scholarly journals Structural and optical properties for PVA- PEG-MnCl2 composites

2019 ◽  
Vol 15 (32) ◽  
pp. 99-113
Author(s):  
Mahdi Hasan Suhail

Polymer films of PEG and PVA and their blend with differentconcentrations of MnCl2 (0, 2, 4, 6 and 10 %.wt) were study usingcasting technique. The X-ray spectra of pure PEG, PVA andPVA:PEG films and with addition of 2% concentrations from(MnCl2) show amorphous structures. The results for FTIR show theinteraction between the filler and polymer blend results indecreasing crystallinity with rich amorphous phase. Thisamorphous nature confirms the complexation between the filler andthe polymer blend. The optical properties of (PVA:PEG/MnCl2)contain the recording of absorbance (A) and explain that theabsorption coefficient (α), refractive index (n), extinction coefficient(ko) and the dielectric constants (real and imaginary part) increasewith increasing the concentration of Composite (PVA:PEG/MnCl2).The optical energy gap for electrons transitions both are direct andindirect allowed.

2021 ◽  
Vol 2114 (1) ◽  
pp. 012012
Author(s):  
Tamara S. Hussein ◽  
Ala F. Ahmed

Abstract In this study, the effect of grafting with Iron (Fe) ratios (0.1, 0.3 and 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 films was examined by X-ray diffraction technique (XRD), which showed that the synthesis of the prepared films is polycrystalline, and Atomic Force Microscope (AFM) images also showed that the increased vaccination with Iron led to an increase in the crustal size ratio and a decrease in surface roughness, The absorption coefficient was calculated and the optical energy gap for the prepared thin films. It was found the absorption decreases and the energy gap decreases with the increase of doping ratio.


2021 ◽  
Vol 13 (01) ◽  
pp. 33-42
Author(s):  
Mushtaq Talib Al-Helaly ◽  
◽  
Nathera A .Al-Tememee ◽  

The research included the preparation and then studying the structural and optical properties of the cobalt dioxide (CoO2)films. The latter films were prepared using a semi-computerized spray pyrolysis technique (SCSPT),. The X-ray diffraction gave polycrystalline nature with crystal system trigonal (hexagonal axes), and the Energy Dispersive X-ray spectroscopy (EDX) showed that all films contain the elements (Co and O) indicating formation of (CoO2) films with high purity. FTIR measurements showed of chemical bonds of CoO2 clearly. Scanning Electron Microscopy (SEM ) Showed clearly that the formed thin films under the optimum conditions were homogeneous, dense and compact, and Atomic Force Microscopy(AFM) results showed that the topography of the film surface where surface roughness was found to be 7.91 nm, root mean square was 9.69 nm., and the average granularity diameter was 78.00 nm. The optical properties (absorbance, absorption coefficient, extinction coefficient, refractive index, optical Conductivity, the real ε_(1 ) and imaginary ε_2 part of the dielectric constant )were decreased with increasing the wavelength, while the transmittance increases with increasing wavelength. The optical energy gap was (1.98eV) and this is a good optical energy gap values for photovoltaic applications.


Author(s):  
Zehraa N. Abdul-Ameer ◽  
Ibrahim R. Agool

ZnO,CdO,ZnO-CdO nanocomposite were prepared using electrochemical deposition the prepared samples were characterized using X-ray diffraction and the photoluminenscence spectroscopy (PL) to get the surface morphology leading to calculation of optical energy gap .the grain size determined by Scherrer's equation (22-25) nm .through the calculation of Eg ,it was noticed a red shift behavior in ZnO manner due to addition of CdO content


2017 ◽  
Vol 35 (2) ◽  
pp. 335-345 ◽  
Author(s):  
A.M. Abd-Elnaiem ◽  
M. Mohamed ◽  
R.M. Hassan ◽  
A.A. Abu-Sehly ◽  
M.A. Abdel-Rahim ◽  
...  

Abstract Chalcogenide glasses have attracted much attention largely due to their interesting physical and chemical properties. Though few published articles exist on the As-Te system, little is known about the optical properties of eutectic or near eutectic composition of As-Te system upon heat treatment. Therefore, this paper reports the effects of annealing temperature on the structural and optical parameters of As30Te70 thin films. The bulk and thin films of 150 nm thick As30Te70 chalcogenide glasses were prepared by melt-quenching and thermal evaporation techniques, respectively. The glass transition and crystallization reactions of the bulk samples were investigated using differential scanning calorimetry (DSC). The influence of annealing temperature on the transformation of the crystal structure was studied by X-ray diffraction (XRD), while the surface morphology of the annealed samples was examined using scanning electron microscope (SEM). The optical band gap, refractive index and extinction coefficient were also calculated. The DSC scans showed that the melting temperature remains constant at 636.56 K. In addition, other characteristic temperatures such as the glass transition temperature, the onset crystallization temperature, and the crystallization peak temperature increase with increasing the heating rate. The crystalline phases for the as-prepared and annealed films consist of orthorhombic As, hexagonal Te, and monoclinic As2Te3 phases. Furthermore, the average crystallite size, strain, and dislocation density depend on the annealing temperature. The optical absorption results revealed that the investigated films have a direct transition, and their optical energy gap decreases from 1.82 eV to 1.49 eV as the annealing temperature increases up to 433 K. However, the refractive index, extinction coefficient, dielectric constant and the ratio of free carrier concentration to its effective mass, increase with increasing the annealing temperature.


2018 ◽  
Vol 29 (1) ◽  
pp. 160
Author(s):  
Iman Hameed Khudayer

The purpose of the present paper is to study the effect of doping by different materials on the structure and the optical properties of Cadmium Telluride films which prepared by rate deposition (4.21 nmn/sec) and thickness (≈ 200 nm) in vacuum by use thermal evaporation technique at a substrate temperature (300K), we are studying the effect of doping by different material (Antimony, Aluminum and Silver) on the structural1and optical2 properties of CdTe thin films. The structural properties of these films have been studied by using X-ray diffraction methods. The optical measurements indicated that Cadmium Telluride films have a direct optical energy gap (Egopt), and it decreases when we doped this films by different materials (Sb, Al and Ag) with the same ratio doping. The optical constants refractive index (n), extinction coefficient (k), absorption coefficient (α) and dielectric constants (r and i) were also studied.


Author(s):  
J. Damisa ◽  
J. O. Emegha ◽  
I. L. Ikhioya

Lead tin sulphide (Pb-Sn-S) thin films (TFs) were deposited on fluorine-doped tin oxide (FTO) substrates via the electrochemical deposition process using lead (II) nitrate [Pb(NO3)2], tin (II) chloride dehydrate [SnCl2.2H2O] and thiacetamide [C2H5NS] precursors as sources of lead (Pb), tin (Sn) and sulphur (S). The solution of all the compounds was harmonized with a stirrer (magnetic) at 300k. In this study, we reported on the improvements in the properties (structural and optical) of Pb-Sn-S TFs by varying the deposition time. We observed from X-ray diffractometer (XRD) that the prepared material is polycrystalline in nature. UV-Vis measurements were done for the optical characterizations and the band gap values were seen to be increasing from 1.52 to 1.54 eV with deposition time. In addition to this, the absorption coefficient and refractive index were also estimated and discussed.


2014 ◽  
Vol 11 (2) ◽  
pp. 518-526
Author(s):  
Baghdad Science Journal

Thin films of pure tin mono-sulfide SnS and tin mono-sulfide for (1,2,3,4)% fluorine SnS:F with Thicknesses of (0.85 ±0.05) ?m and (0.45±0.05) ?m respectively were prepared by chemical spray pyrolysis technique. the effect of doping of F on structural and optical properties has been studied. X-Ray diffraction analysis showed that the prepared films were polycrystalline with orthorhombic structure. It was found that doping increased the intensity of diffraction peaks. Optical properties of all samples were studied by recording the absorption and transmission spectrum in range of wave lengths (300-900) nm. The optical energy gap for direct forbidden transition and indirect allowed transition were evaluated It is found that for doping less than 2% the optical energy gap increases as the percentage of doping increases in the samples while for doping more than 2% the values of the optical energy gap decreases as the percentage of doping increases.


2018 ◽  
Vol 5 (1) ◽  
pp. 1-7
Author(s):  
Ali N. Sabbar ◽  
Karar M. Talib ◽  
Hassan T. Badh

"In this paper, we report upon preparation and optical properties of the polymer blend (50%PMMA:25%PVC:25%PS) thin films. The thin films have been prepared with specific ratios using the casting technique at normal weather conditions. The films were subjected to heat treatment in varying temperatures for three hours. The results showed that increase thermal annealing temperature leads to decrease values of the direct and indirect energy gap, but increase the extinction coefficient and optical conductivity. The refractive index, real and imaginary dielectric constants showed a heterogeneous behaviour. Thermal annealing by 80 oC and up leads to deformation the thin films.


2016 ◽  
Vol 23 (02) ◽  
pp. 1650001 ◽  
Author(s):  
ZAKI S. KHALIFA

Crystal structure, microstructure, and optical properties of TiO2 thin films deposited on quartz substrates by metal-organic chemical vapor deposition (MOCVD) in the temperature range from 250[Formula: see text]C to 450[Formula: see text]C have been studied. The crystal structure, thickness, microstructure, and optical properties have been carried out using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), atomic force microscope (AFM), and UV-visible transmittance spectroscopy, respectively. XRD patterns show that the obtained films are pure anatase. Simultaneously, the crystal size calculated using XRD peaks, and the grain size measured by AFM decrease with the increase in deposition temperature. Moreover, the texture of the films change and roughness decrease with the increase in deposition temperature. The spectrophotometric transmittance spectra have been used to calculate the refractive index, extinction coefficient, dielectric constant, optical energy gap, and porosity of the deposited films. While the refractive index and dielectric constant decrease with the increase of deposition temperature, the porosity shows the opposite.


2017 ◽  
Vol 28 (1) ◽  
pp. 158
Author(s):  
Asrar A. Saeed

Effects of methyl green (MG) dye on the optical properties of polystyrene (PS) have been studied. Pure polystyrene and MG doped PS films were prepared by using casting method. These films were characterized using UV/VIS spectrophotometer technique in order to estimate the type of electric transition which was found to be indirect transition. The value of the optical energy gap was decreased with increasing doping ratios of methyl green dye. Absorption coefficient, extinction coefficient, refractive index and energy gap have been also investigated; it was found that all the above parameters affects by doping dye.


Sign in / Sign up

Export Citation Format

Share Document