Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Optical properties


Influence of Annealing on Properties of Cadmium Oxide thin Films Prepared by Spray Pyrolysis

Jehan A. Saimon; Douaa S. Jbaier; Azhar I. Hassan

Engineering and Technology Journal, 2015, Volume 33, Issue 8, Pages 1458-1466

CdO thin films have been deposited by Spray Pyrolysis Technique (SPT) on a glass substrate. The structural and optical properties of thin films are studied at different annealing temperatures 100, 200 and 300 Co. By using X-Ray Diffraction, XRD patterns indicated that films are polycrystalline innature and cubic phase with preferred orientation along the plane (111). The optical properties using UV-VIS spectroscopy show that the direct band gaps decreased from (3 to 2.75) eV with increasing the annealing temperature from(100-300)Co, this decreasing could be ascribed to increase of the localized states available in band gap which referred by Urbach,s energy value.

Structural and Optical Characterization of Nickel Oxide Thin Films Prepared by Spray Pyrolysis Technique

Fadheela H. Oleiwe

Engineering and Technology Journal, 2015, Volume 33, Issue 8, Pages 1503-1512

In this research, Nickel oxide (NiO) thin film were prepared by using nickel chloride ( NiCl2.6H2O) on glass substrate by using Spray Pyrolysis technique. The Structural and optical properties were studied for the growth thin films under influence different molarities (0.5,1,2 M) by XRD , SEM . The optical properties studied in the wavelength range from 200-1100nm measured by UV-VIS Spectrometer device.
The X-ray diffraction studies indicated that intensity was increased with molarities increase and had cubic structure , these films has grain size values (4.13-11.95 nm) with different molarities (0.5, 1 , 2M) , SEM found the films has smooth surface with grains scattered throughout the surface and the surface the films filled with the clusters of the larger grains the at increase molarities and AFM it is found the (RMS) of NiO films increased from 7.77 to 20.7 nm and the roughness average increased from 5.73-15.6 nm with the increase of molarities from 0.5-2 M .
From the optical studies it is found the film thickness increased with molarities increase, while the transmittance decreased from approximately 75% to approximately 54% and the energy gap for the NiO films varies from ( 3.65 to 3.1eV) as the molarities increase.

Preparation of Silver Nanoparticles and Study the Optical and Antibacterial Properties

Abdulhadi kadhim AL-Ogaili; Abdurahman K. Ali; Tamir H. Ali

Engineering and Technology Journal, 2015, Volume 33, Issue 3, Pages 478-487

In this work,preparationand characterization of Silver nanoparticles which were synthesized by pulsed (Q-switched, 1064 and 532nm doubled frequency-Nd: YAG) laser ablation of silver metal immersed in double distilled and deionized water DDDW, without any chemical additives and studied the optical, and antibacterial properties by using different techniques. The fluence of laser parameters such as number of pulses as well as laser fluence on the properties of nanoparticles elucidated. It has been observed that laser energy and number of laser pulses have a control over the size of the nanoparticles. Increasing laser energy and number of pulses shows a clear blue shift in the absorption peak of fabricated nanoparticles indicating that the average size of the particles decreases with increasing laser energy and number of pulses. Ablation for longer period reduces the average size of nanoparticles.The Antibacterial of synthesized silver NPs against four pathogens: streptococcus, staphylococcus, proteus and Enterobacterwere studied.

Effect of Some Vegetables (Carrots, Onion, Parsley, and Red radish) on Corrosion Behavior of Amalgam Dental Filling in Artificial Saliva

Slafa Ismael Ibrahim; Nemir Ahmed Al-Azzawi; Shatha Mizhir Hasan; Hussein H. Karim; Ammar M. M. Al-Qaissi; Ahmed Chyad Kadhim; Mehdi Munshid Shellal; Sinan Majid Abdul Satar; Wahid S. Mohammad; Assad Oda Jassim; Khalid salem Shibib; Karema Assi Hamad; Haqui Ismael Qatta; Hayder Hadi Abbas; Kanaan A. Jalal; Hussain Kassim Ahmad; Makram A. Fakhri; Mohanned M.H. AL-Khafaji; Hussam Lefta Alwan; Baraa M.H. Albaghdadi

Engineering and Technology Journal, 2014, Volume 32, Issue 5, Pages 1216-1226

This work involves study corrosion behavior of amalgam in presence of some vegetables including (Carrots, Onion, Parsley, and Red radish) which were chosen because they require mastication process by teeth and taking enough time that make them in a contact with amalgams filling in artificial saliva.
The corrosion parameters were interpreted in artificial saliva at pH (5.1) and (37±1oC) by adding (50 ml/l) of vegetable juice to artificial saliva, which involve corrosion potential (Ecorr), corrosion current density (icorr), Cathodic and anodic Tafel slopes (bc & ba ) and polarization resistance, the results of (Ecorr) and (icorr) indicate that the medium of saliva and (50 ml/l) onion is more corrosive than the other media. Cathodic and anodic tafel slopes were used to calculate the polarization resistance (Rp) to know which medium more effective on amalgam of dental filling, this study shows that the increasing in polarization resistance through the decreasing in corrosion rate values, the results of (Rp) take the sequence:
Rp:( saliva+ parsley) >( saliva+ red radish)> saliva>(saliva+ carrots) >(saliva+ onion).
While corrosion rates (CR ) take the sequence:
CR: (Saliva+Parsley) Keywords

Amalgam
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Corrosion in saliva
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Potentiostatic measurements

Effect of Substrate Temperature on Optical and Structural Properties of Indium Oxide Thin Films Prepared by Reactive PLD Method

Makram A. Fakhri

Engineering and Technology Journal, 2014, Volume 32, Issue 5, Pages 1323-1330

In the present Work, effect of substrate temperatures on the optical and morphological properties of In2O3 trioxide thin film has been carried out using Reactive Pulsed Laser as a Deposition technique (RPLD). 1.064µm, 7 nsec Q-switch Nd-YAG laser with 400 mJ/cm2 laser energy’s has been used to ablated pure Indium target and deposited on glass substrates . The resulted films show High transparency reached to about (85) % which found to decrease sharply with the substrate temperatures. The estimated optical band gap found to be about 3.6eV at optimum substrate temperatures (70 Co). The FTIR results insure the formation ofIn-O vibrational bond with different vibrational intensity depending on substrate temperatures.

Enhancement of Porous Silicon Formation by Using Laser Irradiation

Aseel A. Hadi

Engineering and Technology Journal, 2013, Volume 31, Issue 3, Pages 348-356

In this work porous silicon where prepared by chemical etching assisted with laser. The structural and optical properties of porous silicon are investigated using atomic force microscopy (AFM) and FTIR spectroscope. FTIR spectrum exhibit the formation of SiHx (x=1,2) and Si-O bonds. The atomic force microscopy AFM investigation shows the surface roughness (RMS observed was 1.52nm with laser and 1. 86 nm without laser ) and pyramid like hillocks surface on entire surface which can be regarded as a condensation point to form small skeleton clusters which plays an important role for the strong visible luminescence.

Synthetic, Structural and Optical Properties of Cds Nano particles Prepared by Chemical Method

Khawla S. khashan

Engineering and Technology Journal, 2013, Volume 31, Issue 1, Pages 39-48

In this work, CdS nanoparticles were synthesized via chemical method using thioacetamide (TA). X- ray diffraction (XRD), Atomic force microscopy (AFM) and UV-VIS transmission spectroscopy were employed to characterize the size, morphology, crystalline structure and optical properties of the prepared material. X-ray diffraction analysis confirms the formation of cubical and hexagonal structures of CdS nanoparticle with average particle size (3.2nm). AFM show the formation of aggregate of nanoparticle with particle size ranging 7 – 20 (nm). From the shift in optical band gap, particles size can be calculated using Effective mass approximation (EMA) was (2.3nm), and found a good agreement with those determined from XRD broadening, while AFM show higher particle size due to aggregation of nanoparticles.

The Influence of Substrate Temperature on In2O3 being Structured

Mehdi Q. Zayer; Yasmeen Z. Dawood; Mohamad S. Mohamad

Engineering and Technology Journal, 2013, Volume 31, Issue 1, Pages 115-121

In2O3 thin films were grown by the chemical spray pyrolysis (CSP) method using the pneumatic spray set-up and compressed air as a carrier gas. Aqueous solutions containing InCl3.4H2O were deposited onto preheated glass sheets at substrate temperatures Ts=423–573K. X-ray differection (XRD) analysis confirmed the cubic bixbyite structure of indium oxide. The preferred growth orientation along the (211) plane for thin films. The crystallite size extracted from the XRD data corroborates the changes in full width at half maximum due to the variation in substrate temperature. It was shown that grain size of In2O3 thin film was (30)nm. Optical properties of In2O3 was studies and showed that the optical parameters (n, k α) were affected by substrate temperature.

Optical and Structure Properties of MgxZn1-xO Thin Films by Pulsed Laser Deposition

Gehan E. Simon; Adawiya J. Haidar

Engineering and Technology Journal, 2009, Volume 27, Issue 14, Pages 2653-2665

In this study, the optical and structure properties of MgxZn1-xO thin films is reported. The MgxZn1-xO thin films were prepared on Glass substrates by Q-switch second harmonic Nd:YAG laser deposition technigue with wavelength of 532nm from a ZnO target mixed with Mg of (0-0.3) wt% , and the films deposited at temperature (250°C).
The optical properties were characterized by transmittance and absorption spectroscopy measurements. For all the films the average transmission in the U.V (200-900) nm wavelength region was over 85% and the absorption edge shifted to a shorter wavelength as the magnesium concentration increased. The optical energy gap of MgxZn1-xO thin films, measured from transmittance spectra could be controlled between (3.3eV and 4.2eV) by adjusting magnesium concentration. X-ray diffraction was used to investigate the structure of the film. The refractive index of hexagonal MgxZn1-xO thin films decreases with the Mg concentration increase, such as at the wavelength of (500nm) the refractive index decreases from 1.93 to 1.85 as x increase from 0.15 to 0.3. The extinction coefficient and the complex dielectric constant were also investigate.

The Effect Of Thermal Oxidation Time On The Structure And Influence On Optical Properties For Porous Silicon Prepared By Photo Electrochemical Etching

Narges Z.Abd alzahra; Alwan M.Alwan

Engineering and Technology Journal, 2009, Volume 27, Issue 4, Pages 727-735

The morphological properties of the freshly and oxidized porous silicon at
oxidation time (60, 90) sec were studied. A blue emission from PSi can be seen with
eyes after thermal oxidation because the increasing of energy gab due to decreased
silicon column (nano particles).Pore size and shape of n-type wafers are estimate and
correlated with optical properties before and after rapid thermal oxidation (RTO).