scholarly journals FACILE SYNTHESIS AND OPTICAL PROPERTIES OF PbO NANOSTRUCTURES

2014 ◽  
Vol 44 (2) ◽  
pp. 159-162
Author(s):  
R. YOUSEFI ◽  
F. JAMALI-SHEINI ◽  
M. CHERAGHIZADE ◽  
A. SA'AEDI

PbO nanostructures were synthesized by the oxidation of lead sheets in a tube furnace under oxygen ambient using different temperatures, from 280 °C to 450 °C. X-ray diffraction patterns (XRD) indicated the formation of α-PbO nanostructures from the lead sheet with an increase in the temperature. Scanning electron microscope (SEM) results showed that flake-like shapes were starting to grow on the lead sheet that was placed in the 280 °C. In addition, the SEM studies showed nanoflake and nanoporous morphologies for the lead sheets that were placed at 330 °C and 450 °C, respectively. Raman measurements confirmed the XRD results and indicated two Raman active modes that belonged to the α-PbO phase for the nanoflakes and the nanoporous surface. The optical properties of the products were characterized using a photoluminescence (PL) technique. The PL results for the PbO nanoflakes and nanopores showed a peak in the visible region.

2021 ◽  
Vol 1039 ◽  
pp. 307-312
Author(s):  
Mohammad Malik Abood ◽  
Osama Abdul Azeez Dakhil ◽  
Aref Saleh Baron

Methyl ammonium lead iodide CH3NH3PbI3 Perovskite was synthesized by a new method mixing between one and two steps, in addition, the ethanol solvent was used to dissolve CH3NH3I and compared with isopropanol solvent. The characterizations of synthesized perovskite samples included the structural properties, morphological characteristics and optical properties. The intensity and orientation in X-ray diffraction patterns appear clearly in ethanol solvent while disappearing at a peak at 12o due to the speed reaction of perovskite in this solvent. Additionally, the ethanol solvent increasing the grain size of perovskite which homogeneity of the surface morphology. the ethanol solvent cause a decrease in the wavelength of absorbance edge in addition to an increase in the energy bandgap value. Keywords: Ethanol Solvent, Perovskite, Photovoltaic Technologies, X-ray diffraction.


2008 ◽  
Vol 8 (3) ◽  
pp. 1523-1527 ◽  
Author(s):  
Poulomi Roy ◽  
Suneel Kumar Srivastava

The present work reports the effect of reaction time on solvothermal synthesis of copper sulfides from CuCl2·2H2O and thiourea with various compositions and morphologies using ethylenediamine as solvent at 120 °C. X-ray diffraction patterns of the products at different durations shows the development of different stoichiometric composition of copper sulfides in where Cu:S ratio increases from 1.39 to 1.79 indicating transformation of Cu39S28 to Cu7S4. As inferred by EDX and XPS studies of the final products. SEM shows the growth of bundles of nanorods of length ≈1 μm and diameter in nanometer range are observed after 6 h. On increasing the reaction duration to 9 h, nanorods tends to combines with each other and growth occurs in six directions and after 12 h leads to the formation of flower-like morphology of copper sulfide. The optical properties of these products also have been studied.


2012 ◽  
Vol 329 ◽  
pp. 139-145
Author(s):  
S.A. Aly

A Vanadium Pentoxide Sample with a Film Thickness of 75 Nm Has Been Thermally Evaporated on Unheated Glass Substrate Using V2O5High Purity Powder. the Sample Was Subjected to a Subsequent Post-Deposition Annealing in Air at Different Temperatures for a Period of One Hour. the Optical Properties Were Studied by Transmittance and Reflectance Measurements. the Integrated Visible ,TVis, and Solar, TSol, Transmittance Were Calculated. the Spectral Behaviour of the Refractive Index as Well as the Absorption Coefficient before and after Post-Deposition Heat-Treatment Was Also Reported. X-Ray Diffraction Confirmed that the Film in the as-Deposited as Well as after Annealing up to 400 °C Is in the Amorphous State.


2011 ◽  
Vol 306-307 ◽  
pp. 1722-1727 ◽  
Author(s):  
Man Mei ◽  
Li Li Cao ◽  
Yan He ◽  
Ru Ru Zhang ◽  
Fei Yun Guo ◽  
...  

The calcium terbium aluminate (CaTbAlO4) single crystal was grown by Czochralski method successfully for the first time.The structure of the crystal was determined by X-ray diffraction analysis.The transmission spectrum of the crystal was measured at room temperature at the wavelength of 400-1500nm.The specific Faraday rotation of the single crystal was surveyed at room temperature at the wavelength 532nm, 633nm, and 1064nm respectively.The Verdet constants of the CaTbAlO4 crystal are calculated and the results show that the Verdet constants of CaTbAlO4 are around 110% higher than that of TGG in the visible and near-infrared spectral region.Therefore,crystal CaTbAlO4 can be promising material for the fabrication of magneto-optical devices in the visible region.


2012 ◽  
Vol 442 ◽  
pp. 3-7
Author(s):  
Qian Ming Wang ◽  
Zheng Yang Zhang ◽  
Yan Li

Cerium and gadolinium phosphate micro-meter size phosphors with average diameters of 20-50 μM were prepared. X-Ray Diffraction (XRD) data confirmed the crystalline phases of samples could be formed at different temperature. Scanning electron microscopy (SEM) investigated the morphology and crystalline of the samples, showing that many regular and large pores (100-200 μM) were dispersed within the micro-meter scale composites. We have proved the above crystal growth structures were controllable and predicable based on the current conditions.


2015 ◽  
Vol 1132 ◽  
pp. 217-223
Author(s):  
E.R. Rwenyagila ◽  
B. Agyei-Tuffour ◽  
M.G.Z. Kana ◽  
O. Akin-Ojo ◽  
W.O. Soboyejo

This work examines the modification of the structural and optical properties of ZnO thin films by control of deposition and post-treatment parameters. ZnO thin films were deposited by RF magnetron sputtering from a ceramic target locally made at SHESTCO in Abuja, Nigeria. X-ray diffraction measurements characterized the different films prior to thermal annealing as extremely amorphous with average UV-VIS transmittance spectra between 80 and 90%. Annealing at different temperatures and time spans influenced the formation of Wurtzite (002) oriented ZnO crystallites. Contrary to the crystallinity of the films, which was strongly influenced by the deposition power, the optical transmission of the films was only slightly influenced by the deposition power and it was less sensitive to the crystallinity of ZnO thin films.


2021 ◽  
Author(s):  
aimane guedri ◽  
Mourad ZAABAT ◽  
Boubekeur BOUDINE ◽  
Abdelkader HAFDALLAH

Abstract Considered Technique spin coating of the most important techniques used to prepare thin films because it is easy to use and inexpensive since it is closely dependent on the number of layers deposited. This work aims to study the effect of samples thickness for nanocomposites of polyvinyl chloride doped with zinc oxide nanoparticles on the structural, optical properties, and photocatalytic activities. Nanocomposite films of polyvinyl chloride (PVC) - zinc oxide (ZnO) with a different number of the deposited layers (15, 20, 25, and 30 layers) were synthesized by a sol-gel method (spin coating) using tetrahydrofuran as a solvent, and investigated by various techniques. X-ray diffraction measurements indicated in the case of 15, 20, and 25 layers do not clearly show the presence of diffraction peaks. On the other hand, in the case of 30 layers, the presence of several peaks is observed, which testify to the presence of ZnO crystallites of wurtzite structure in PVC films. The size of the crystallites is almost equal to 32 nm depending on the working conditions. Raman and infrared spectra confirmed the result of X-ray diffraction on the incorporation of ZnO crystallites in the films produced by showing peaks corresponding to the modes of vibration of the crystal lattice of the ZnO doping semiconductor. Optical transmittance spectra have shown that The layers obtained have an optical transmission varying from 75 to 86% in the visible region of the spectrum. The values of the band gap energies, determined from the transmission spectra for the films deposited on glass, vary between 3.45 and 3.94 eV. The Photoluminescence spectra of ZnO/PVC nanocomposites studied revealed a strong ultraviolet and green luminescence, attributed to structural defects in the zinc oxide. The photocatalytic reaction has been shown using MB in the UV irradiation action of films stacked in an MB solution. The result showed that the 30-layer (PVC / ZnO) sample gave an efficiency to remove MB of 79% at 60 min, Similar to other samples which gave a lower efficiency.


2020 ◽  
pp. 1307-1312
Author(s):  
Wadaa S. Hussein ◽  
Ala' Fadhil Ahmed ◽  
Kadhim A. Aadim

The current study was achieved on the effects of laser energy and annealing temperature on x-ray structural and optical properties, such as the UV-Visible spectra of cadmium sulfide (CdS). The films were prepared using pules laser deposition technique (PLD) under vacuum at a pressure of 2.5×10-2 mbar with different laser energies (500-800 mJ) and annealing at a temperature of 473K. X-ray diffraction patterns and intensity curves for the CdS showed that the formation of CdS multi-crystallization films at all laser energies. The optical properties of the films were studied and the variables affecting them were investigated in relation to laser energy and changes in temperature.


2021 ◽  
Author(s):  
A.R. Makhdoom ◽  
Qasim Ali Ranjha ◽  
Ubaid-ur-Rehman Ghori ◽  
Muhammad Ahsan Raza ◽  
Binish Raza ◽  
...  

Abstract M-type hexaferrites has attracted researchers due to their ordinary magnetic properties and utilization as media for magnetic recording and microwave devices. In this study we have synthesized Ba0.5Sr0.5Fe9Ce1Al2O19 via conventional ceramic route. The synthesized material is treated against different temperatures and investigated structurally and magnetically by using several techniques such as X-ray diffraction, Scanning electron microscopy, and VSM respectively. Morphology of samples confirms the absence of secondary phases and uniform distribution of particles. X-ray diffraction patterns confirms the formation of pure phase of Hexaferrites. Microstructural analyses show the decrease in porosity and dislocations among sintered samples. Magnetic properties for the samples show a decrease in Ms and Mr with increasing temperature from 1225 °C to 1310 °C, while coercivity shows an increase with increasing temperature and maximum coercivity is observed at 1290 °C. The trends and occurrences can be well-linked to the structural variations and sintering effects. The results suggest that material can be used in various magnetic applications such as Recording media, and memory devices.


2013 ◽  
Vol 46 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Bertalan Jóni ◽  
Talal Al-Samman ◽  
Sandip Ghosh Chowdhury ◽  
Gábor Csiszár ◽  
Tamás Ungár

Tension experiments were carried out at room temperature, 473 K and 673 K on AZ31-type extruded magnesium alloy samples. The tensile deformation has almost no effect on the typical extrusion texture at any of the investigated temperatures. X-ray diffraction patterns provided by a high-angular-resolution diffractometer were analyzed for the dislocation density and slip activity after deformation to fracture. The diffraction peaks were sorted into two groups corresponding either to the major or to the random texture components in the specimen. The two groups of reflections were evaluated simultaneously as if the two texture components were two different phases. The dislocation densities in the major texture components are found to be always larger than those in the randomly oriented grain populations. The overwhelming fraction of dislocations prevailing in the samples is found to be of 〈a〉 type, with a smaller fraction of 〈c + a〉-type dislocations. The fraction of 〈c〉-type dislocations is always obtained to be zero within experimental error.


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