The goal of this investigation is to prepare zinc oxide (ZnO) nano-thin films by pulsed laser deposition (PLD) technique through Q-switching double frequency Nd:YAG laser (532 nm) wavelength, pulse frequency 6 Hz, and 300 mJ energy under vacuum conditions (10-3 torr) at room temperature. (ZnO) nano-thin films were deposited on glass substrates with different thickness of 300, 600 and 900 nm. ZnO films, were then annealed in air at a temperature of 500 °C for one hour. The results were compared with the researchers' previous theoretical study. The XRD analysis of ZnO nano-thin films indicated a hexagonal multi-crystalline wurtzite structure with preferential growth lines (100), (002), (101) for ZnO nano-thin films with different thicknesses of un-annealed samples and after annealing. While the UV-Visible spectrum manifested that the ZnO has a high absorption at UV range and wide energy gap values of (3.4, 3.42, and 3.46 eV) for the three thicknesses. The surface topography of the films evinced a rough surface which increased with increasing thickness, whereas the grain size decreased, and the average grain size was about 56.68 nm. Furthermore, the nano-thin films showed a granular morphology with a tendency to form smaller particles with increasing thickness.
In this work the Aluminum plasma in Air produced by Nd: YAG pulsed laser, (λ = 1064 nm, τ = 6 ns) has been studied with a repletion rate of 10 Hz. The laser interaction in Al target (99.99%) under air atmosphere generates plasma, which is produced at room temperature; with variation in the energy laser from 600-900 mJ. The electron temperature and the electron density have been determined by optical emission spectroscopy and by assuming a local thermodynamic equilibrium (LTE) of the emitting species. Finally the electron temperature was calculated by the Boltzmann plot from the relative intensities of spectral lines and electron density was calculated by the Stark-broadening of emission line.
During of Experimental result of this work , we found that the change of electrical conductivity proprieties of tin dioxide with the change of gas concentration at temperatures 260oC and 360oC after treatment by photons rays have similar character after treatment isothermally. We found that intensive short duration impulse annealing during the fractions of a second leads to crystallization of the films and to the high values of its gas sensitivity.
In this work, synthesis of conducting polymeric films namely, PVC thin films was carried out containing Schiff base (L) with Cu2+, Cr3+, Ni2+, Co2+, in addition to inspecting the possibilities of measuring energy gap values of PVC-L-M with variety metal ions. These new polymeric films (PVC-L-M) were characterized by FTIR spectrophotometry, energy gap and surface morphology. The optical data recorded that the band gap values are influenced by the type of metals. All modified films have a red shift in optical properties in the ultraviolet region. The PVC-L-Co(II) was the lowest value of the optical band gap, 3.1 eV.
Microscope images are characterized by a number of specific parameters, the influence of such parameters (intensity, magnification, numerical aperture, diaphragms aperture, segmentation, and edge detecting technique) on measurement in optical microscope images have been determined with using a powerful image processing methods. As one of the most widespread techniques in biological investigation and dynamic process, light compound microscopy has used to analyze the optical properties of biological images. The results indicate that a wide aperture allows maximum resolution and depth of field, but decreases the contrast. While a small aperture improve visibility and contrast but decreases the resolution. The results also show the best perf
... Show MoreIraqi oil crudes have some of the physical and chemical characteristics that distinguish it from other types of oil crudes in the world. Some of these features such us molecular composition, rheological, viscosity and emulsions are studied carefully by researchers. In this work, a comparative study of the linear and the non-linear optical properties for typical heavy and light crude oils of Iraqi origin was studied utilizing Z-scan technique. The He -Ne laser of wavelength 632.8 nm had been used for this purpose. These samples were collected from Basra and Kut oil fields. The values of the non-linear refractive index (n2), non-linear absorption coefficient (β), and third-order electrical susceptibility (χ3) were e
... Show MoreThe analytical study of optical bistability is concerned in a fully
optimized laser Fabry-Perot system. The related phenomena of
switching dynamics and optimization procedure are also included.
From the steady state of optical bistability equation can plot the
incident intensity versus the round trip phase shift (φ) for different
values of dark mistuning
12
,
6
,
3
,
1.5
0 , o
or finesse (F= 1, 5, 20,
100). In order to obtain different optical bistable loops. The inputoutput
characteristic for a nonlinear Fabry-Perot etalon of a different
values of finesse (F) and using different initial detuning (φ0) are used
in this rese
The effect of different Ti additions on the microstructure of Al-Ti alloy prepared by powder metallurgy was investigated. A certain amount of Ti (10wt%, 15wt%, and 20wt%) were added to aluminium and the tests like microhardness, density, scanning electron microscope (SEM), optical microscope (OM) and X-Ray Diffraction (XRD) were conducted to determine the influence of different Ti additives on the Al-Ti alloy properties and microstructure. The results show that the grains of α-Al changed from large grains to roughly spherical and then to small rounded grains with increasing Ti content, the micro-hardness of the alloy increases with increasing Ti, and XRD results confirm the formation of TiAl3 intermetallic co
... Show MoreSamples of tea leaves (Green tea, Gugarate tea and Black tea used commonly in Iraq) are dried, grinded, pressed and submitted for the elemental analysis by x-ray fluorescence technique (XRF). The concentrations of major, minor and trace elements are determined. The major elements were Na, Mg, Al, K, Si, Ca, Mn, Fe, S and P. Of these elements, Ca, concentration in Gugarate tea leaves is three times, it's level in the other types of tea. Titanium, Cl, Rb and Sr are found as minor elements, while other elements such as Cu, Zn, V, Cr, Co, ...etc are found as trace elements. Of these trace elements considerable concentration values are found for some toxic elements Hg, Cd, Pb and As. Green tea contains 1.1 ppm Hg and 4.4 ppm Pb. Gugarate tea
... Show MoreMixed phase rutile/anatase of TiO2 was prepared and studied by a closed field DC magnetron sputtering configuration (CFDCMS). It was found that the contents of rutile increased from the ratio of 38% to 53% as the deposition time increased from 3.5 hours to 4.5 hours.
The photocatalytic activity of the mixed phase rutile/anatase TiO2 was measured by monitoring the degradation of the blue methylene dye in an aqueous solution, under exposure to UV-radiation, using UV-vis absorption spectroscopy. It was proven that the photocatalytic activity in the mixed phase (TiO2) is a function of rutile content reaching a maximum value at 53% rutile. Thus, the effect of synergy between anatase- TiO2 and rutile- TiO2 was observed. It was observed that