scholarly journals "Effect Of Thermal Annealing On The Optical Properties Of Thin Films Of Polymer Blend (PMMA:PVC:PS) "

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.

Author(s):  
Kadhim A. Aadim ◽  
Khalid Haneen Abass ◽  
Qunoot M. Hadi

TiO2 thin films were prepared by pulse laser deposition technique on glass substrates with laser power 700 mJ and 900 shot at distance 1cm under vacuum of 10-2 mbar with different annealing temperature (273, 373, 423)K. The influences of the annealing temperature on the optical properties of TiO2 thin films were mainly investigated. TiO2 is a wide band gap n-type semi-conductor that has a wide range of applications. It was found that the optical properties of TiO2 thin films were dependent on the annealing temperature. The values of optical energy gap decreases from (3.4 to 3.2) eV when increasing annealing temperature. The optical constants such as refractive index, extinction coefficient, real and imaginary dielectric constants as a function of wavelength were determined.


2017 ◽  
Vol 14 (2) ◽  
pp. 123-127 ◽  
Author(s):  
M. Ravindar Reddy ◽  
M. Jaipal Reddy ◽  
A. R. Subrahmanyam

This paper is a report of a study conducted on Structural, thermal and optical Properties of pure PMMA, pure PEO and PMMA-PEO-LiClO4 polymer blend electrolyte thin films. These films were prepared using solution casting technique and characterized by X-ray Diffractometer (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC). XRD analysis Observations confirmed that amorphous, crystalline and semi crystalline nature of pure PMMA, pure PEO and PMMA-PEO-LiClO4 polymer blend electrolyte thin films the SEM micrographs suggest that the surface morphology of pure PEO changes from smooth to rough when PMMA and LiClO4 added to PEO polymer, which shows the interaction/ interface between the two polymers and polymer blend electrolyte due to cross – linking. Glass transition (Tg) and melting temperatures (Tm) of pure PMMA, pure PEO and PMMA-PEO-LiClO4 polymer blend electrolyte thin films were confirmed by DSC analysis. FTIR spectra confirmed that complex formation and interaction among PMMA, PEO polymers and LiClO4 salt.


2021 ◽  
Vol 03 (03) ◽  
pp. 41-50
Author(s):  
Hiyam Ch. MAJED

Thin films of cadmium oxide (CdO) deposited on glass substrates using Nd-YAG laser wavelength (alpha= 532 nm) and period time (10ns) via laser-induced plasma deposition technique (PLD). The structural properties of these films have been described as a change in thickness (200 , 400 ,and 1000) nm) at substrate temperature of (400 ° C) and energy flounce of (0.4 J / cm2). The X-ray diffraction results show that he mean size of crystallite measured using Scherer formula to adjust the thickness of 200 nm, 400 nm and 1000 nm of CdO thin films is 47 nm, 64 nm and 78 nm respectively .Also the optical properties which included transmittance, absorbance , energy gap and optical constant such as the Refractive index, extinction coefficient real and imaginary parts of dielectric constants were determined .


Author(s):  
Khalid Haneen Abass

Spray pyrolysis method that used to prepare Cu:NiO thin films onto glass substrate with various annealing temperature. Spectral transmittance of prepared thin films determined by UV-Visible spectrophotometer in the range of (380-900) nm. The transmittance decreased with increasing annealing temperature. While the absorption coefficient and extinction coefficient increased with increasing annealing temperature. Energy gap decreased from 2.9 eV before annealing to 2.78 eV after 500 °C annealing temperature.


Author(s):  
Nadir Fadhil Habubi ◽  
Sami Salman Chiad ◽  
Khalid Haneen Abass ◽  
Mahmood Muwafaq Abood

Nickel oxide doped Fe2O3thin films have been prepared by spray pyrolysis technique on glass substrate. The initial solution was including a 0.1 M/L for both NiCl2and FeCl3diluted with redistilled water and a few drops of HCl. The effect of annealing temperature on optical properties was studied, using UV-Visible spectrophotometer to determine absorption spectra at a thickness of 400 nm. The reflectance increased with increasing annealing temperature, such as α, k, and n.While the transmittance decreases with increasing annealing temperature and the energy gap decreased from 2.68 eV before annealing to 2.70 eV after 500°C annealing temperature.


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.


2018 ◽  
Vol 31 (1) ◽  
pp. 50
Author(s):  
Sarmad M. Ali ◽  
Alia A.A. Shehab ◽  
Samir A. Maki

   The ZnTe alloy was prepared as  deposited thin films on the glass substrates at a thickness of 400±20 nm using vacuum evaporation technique at pressure (1 × 10-5) mbar and room temperature. Then the thin films under vacuum (2 × 10-3 mbar) were annealing at (RT,100 and 300) °C for one hour. The structural properties were studied by using X-ray diffraction and AFM, the results show that the thin films had approached the single crystalline in the direction (111) as preferred orientation of the structure zinc-blende for cubic type, with small peaks of tellurium (Te) element for all prepared thin films. The calculated crystallite size (Cs) decreased with the increase in the annealing temperature, from (25) nm before the annealing to (21) nm after the annealing. The images of atomic force microscopy of all thin films appeared a homogenous structure and high smoothness through roughness values ​​that increased slightly from (1.4) nm to (3.4) nm. The optical properties of the ZnTe at (RT,100 and 300) °C were studied transmittance and absorbance spectrum as a function of the wavelength. The energy gap was found about (2.4) eV for the thin films before the annealing and increased slightly to (2.5) eV after annealing at 300 °C  


2019 ◽  
Vol 16 (39) ◽  
pp. 1-10
Author(s):  
Lamiaa K. Abbas

The effect of heat treatment using different annealing temperatures on optical properties of bulk heterojunction blend (BHJ) Alq3: C60 thin films which are fabricated by the spin coating technique were investigated in this study. The films have been coated on a glass substrate with speed of 2000 rpm for one min and treated with different annealing temperature (373, 423 and 473) K under vacuum. The optical properties and the chemical bonds structure of blends as-deposited and heat treated have been studied by UV-Vis spectroscopic and Fourier Transform-Infra Red (FTIR) measurements respectively. The results of UV visible show that the optical energy gap decreasing with increasing the annealing temperature for the ratio (100:1) while decreasing with increasing the annealing temperature for ratio (100:10). The FTIR spectra measurement were applied to know the type of the bonds of Alq3: C60 BHJ thin films.


2018 ◽  
Vol 12 (3) ◽  
pp. 209-217 ◽  
Author(s):  
Alaa Abd-Elnaiem ◽  
Samar Moustafa

Chalcogenide glasses have received lots of attention because of their superior optical properties. To optimize these properties and expand areas of applications, more studies are required to establish the extent to which the parameters can be tuned over a wide range of annealing temperatures and heating rates. To do this, bulk and thin ?150 nm As30Te67Ga3 films were prepared by melt-quenching and thermal evaporation techniques, respectively. The phase transition was investigated using differential scanning calorimeter (DSC) while the crystal structures were studied by X-ray diffraction (XRD). Characteristic temperatures such as the glass transition, crystallization and melting temperature of the bulk glass were found to depend on the heating rate. The activation energy of glass transition was 167.29 kJ/mol while the energy of crystallization was 103.98 kJ/mol. XRD results indicated that the annealed films showed more crystallinity, larger average crystallite size, lower dislocation density and lower strain as annealing temperature increased. According to the Avrami exponent, a combination of two and three-dimensional crystal growth with heterogeneous nucleation are possible mechanisms for the crystallization process. Moreover, optical constants such as the optical band gap, refractive index, extinction coefficient, high-frequency dielectric constants, real and imaginary parts of dielectric constants were found to strongly depend on the annealing temperature. The optical energy gap decreased from 1.1 to 0.89 eV as the annealing temperature increased from 373 to 433K. These results indicate that thermal annealing is a major factor that can be used to tune the crystal structure, and hence the optical properties of As30Te67Ga3 system.


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