scholarly journals Investigation of the Temperature on the Thin Layers of Cobalt Oxide Produced by the Spray Pyrolysis Method Using a Solar Oven

2021 ◽  
Vol 63 (1) ◽  
pp. 163-176
Author(s):  
Abderrezak Gharbi ◽  
Said Benramache ◽  
Lahcen Fella ◽  
Aziez Zedouri

Abstract Thin films of cobalt oxide (Co3O4) were prepared on glass substrates by the spray pyrolysis method using a solar concentrator (oven) manufactured in our laboratory. We used different processing temperatures (300° C, 350° C and 400° C). The structural, optical and electrical properties of the different samples were analyzed by X-ray diffraction (XRD), UV-Visible spectroscopy and the Hall effect measurement system. X-ray diffraction observations revealed that cubic crystals are created in all films produced, and the film structure is that of a single phase created with preferential orientation along the (311) axis in films at low temperatures, and the axis (111) for high temperatures. The grain sizes of our products vary between (22.62nm and 66.19nm), depending on the processing temperature. The optical band gap of the crystals obtained was measured. The results of the optical forbidden bands of the crystals obtained, indicated two bands of the values for each element (Eg1 and Eg2). We observed that the values of the effective optical forbidden bands increase by 2.547eV and 3.0731eV with the increase in the production temperature., In addition the film produced experiences a decrease in the Urbach parameters which vary between 162.20meV and 360.81meV depending on the increase in production temperatures. Finally, the films produced have electrical conductivity values of (1.090 [(Ω.cm)−1] to 1.853 [(Ω.cm)−1] and electrical resistivity values of 1.431 (Ω.cm) at 1.853 (Ω.cm), depending on the variation in the production temperature.

1987 ◽  
Vol 99 ◽  
Author(s):  
Maki Kawai ◽  
Tomoji Kawai ◽  
Hiromi Masuhira ◽  
Makoto Takahasi

ABSTRACTAn oriented film of YBa2Cu3O7−x superconductor was formed by a spray pyrolysis method. The temperature dependence of resistance showed the Tc-onset at 95K and Tc-zero at 83K with the film on a cubic zirconia single crystal surface. The X-ray diffraction pattern showed that the structure of the film was pure orthorhombic phase. Effect of the substrates and the modification of the substrates surface to form superconductive films are presented.


2020 ◽  
Vol 853 ◽  
pp. 56-60
Author(s):  
Alexa Gaona-Esquivel ◽  
Diana S. Hernández-Manzo ◽  
Perla J. Sánchez-Trujillo ◽  
Oscar E. Cigarroa-Mayorga ◽  
Miguel Meléndez-Lira

In this work, the synthesis of manganese oxide nanoparticles was achieved by one-step spray pyrolysis method. The nanoparticles were synthesized just from MnCl2 aqueous solution. The solution was nebulized to a Si substrate placed at 400 °C for 1, 5 10 and 20 min and transported at a 0.1 L /min rate in a Nitrogen flux. The X-ray diffraction confirms tetragonal Mn3O4 as the unique phase in the whole sample. The scanning electron microscopy images proved the achievement of irregular nanoparticles with an average diameter of 280 nm experimentally determined by dynamic light scattering. Energy dispersive X-ray and Raman spectroscopy confirmed that the nanoparticles were obtained with Mn3O4 single-phase and the employed methodology prevented any contamination. The nanoparticles proved to induce temperature enhancement on artificial breast tissue by exposition to microwave radiation by achieving an increase in temperature around 8 %.


Quimica Hoy ◽  
2011 ◽  
Vol 1 (2) ◽  
pp. 5
Author(s):  
A. Arato ◽  
S.M. García Montes ◽  
G. Alan Castillo ◽  
T.K. Dasroy

Undoped and tin (Sn) doped zinc oxide (ZnO) thin film have been deposited by spray pyrolysis method of zinc acetate and tin chloride. Toe concentration ratio of[Sn ]/ [Zn] was varied from 0-5 at %. Toe effect of doping Sn on physical and optical properties was studied by different techniques such as X-ray diffraction for structural characterization, SEM for thickness and morphology, UV-Vis spectroscopy for optical properties, Hall effect and photoconductivity for electrical characterization. X-ray diffraction (XRD) patterns show that the films deposited are polycrystalline with (002) plane as the preferential orientation. According to Scherrer's equation, grain size values on the films are found between 30 - 45 nm with spherical shape. Optical transmittance was about 92% in visible range for the optimum film and shows that the band gap decreases from 3 .29 to 3.17 e V.


2005 ◽  
Vol 868 ◽  
Author(s):  
S. Phok ◽  
P.D. Spagnol ◽  
T. Chaudhuri ◽  
R.N. Bhattacharya

AbstractBiaxially textured YBa2Cu307-δ films were fabricated by non-vacuum electrodeposition and spray pyrolysis techniques. Electrodeposited YBCO was prepared on sputtered copper/single-crystal substrates. Electrodeposition was carried out at constant voltage and the deposition was completed in only few minutes. The thickness of the as-deposited films was in the range of 0.6 to 2 μm. The optimized sputtered copper layer thickness was about 200 Å on SrTiO3. In the spray pyrolysis method, the solution is sprayed directly onto SrTiO3 substrates. The substrate temperature is about 100°C. The thickness of the as-deposited films was in the range of 1.2 to 2μm. The electrodeposited and spray-deposited films were annealed at temperatures ranging from 800° to 920°C under various flowing gas mixtures. X-ray diffraction analysis revealed that processed electrodeposited and spray-deposited films were biaxially textured, where YBCO grains were well oriented along the c-axis and in the (a,b) plane. Δω, deduced from the rocking curve on the (005) reflection, was as low as 0.46°. Δφ, deduced from the phi-scan on the (103) reflection, was as low as 0.54°. The critical current density for these types of films is about 0.5 MA/cm2at 77 K and 0 T.


2018 ◽  
Vol 1 (1) ◽  
pp. 57-66
Author(s):  
Fenfen Fenda Florena ◽  
◽  
Dwindra Wilham Maulana ◽  
Ferry Faizal ◽  
Bambang Mukti Wibawa ◽  
...  

Spherical particles of Zn doped MgO were prepared by one-step spray pyrolysis method. The crystalline nature and particle size of the samples were characterized by X-ray diffraction analysis (XRD). The morphology of samples was studied by scanning electron microscope (SEM) and the presence of Zn in the sample was confirmed by energy dispersive X-ray analysis (EDX). The optical properties of the samples were investigated using photoluminescence spectroscopy (PL) analysis to obtain excitation and emission spectra of the samples. Results indicated that the doped MgO particles exhibited a cubic structure without hexagonal wurtzite structure as the Zn concentrations were increased. Spherical shape and porous particles are found with increasing of doping concentration. The optical band gap of MgO altered with the addition of doping concentration. A considerable redshift of about ~0.08 – 0.13 eV in the excitation spectra of 2.22 eV emission band was revealed in Zn doped MgO samples. It was highlighted that Zn doped MgO prepared by the spray pyrolysis generated emission at UV-Vis wavelength required for many applications.


2013 ◽  
Vol 652-654 ◽  
pp. 563-566
Author(s):  
Xia Wang ◽  
Chang Cheng Liu ◽  
Zhen Hua Liang ◽  
Gui Hua Peng ◽  
Xiao Bao Han

Hollow spherical CaMoO4:Eu3+, Li+red phosphors have been successfully synthesized by spray pyrolysis method. The crystalline phase, morphology and luminescent properties of the obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence emission spectra (PL). The XRD results demonstrated that all the diffraction peaks of the samples can be well indexed to the tetragonal phase of CaMoO4. The SEM images showed that the particles were composed of hollow spheres, whose diameters are about 1.4 μm. The as-prepared CaMoO4:Eu3+, Li+hollow spheres show a strong red emission corresponding to the5D0-7F2transition of the Eu3+ ions under ultraviolet light.


2013 ◽  
Vol 737 ◽  
pp. 20-27 ◽  
Author(s):  
Camellia Panatarani ◽  
Dunden Gilang Muharam ◽  
Bambang Mukti Wibawa ◽  
I Made Joni

A blue luminescent of ZnO:Zn nanocrystal has been successfully prepared by one step spray pyrolysis method without reducing gas atmosphere. Zinc acetate dihydrate aqueous solutions (0.05 M) were atomized by ultrasonic atomizer. The atomizer used an air as carrier gas with 1, 3 and 5 L/min flowrate. The tubular reactor was set at 500, 600 and 700oC. As prepared samples were characterized by means of x-ray diffraction spectroscopy and scanning electron microscope-energy dispersive x-ray spectroscopy (SEM-EDS). The crystal size of as prepared particles calculated by Scherrer’s equation give 10-20 nm. The luminescent properties of as prepared particles were measured using spectrofluorophotometer. The highest photoluminescent intensity of particles irradiated with excited wavelength of 250 nm was obtained from samples prepared using 5 L/min carrier gas with temperature of tubular reactor 700oC. High intensity of blue luminescent was obtained due to oxygen vacancy in ZnO:Zn.


1991 ◽  
Vol 6 (2) ◽  
pp. 264-269 ◽  
Author(s):  
Michael R. Zachariah ◽  
Serge Huzarewicz

Submicron YBa2Cu3O7−δ particles have been produced in an aerosol flame reactor by a spray pyrolysis method in which an aerosol composed of an aqueous solution of Y, Ba, and Cu nitrate salts was introduced into a flame. It was observed that the configuration of the flame is particularly important for the successful application of the method. A premixed flame gave particles with an x-ray diffraction pattern resembling the XRD spectra of materials exposed to high concentrations of water vapor. An over-ventilated diffusion flame configuration produced the desired result: submicron unagglomerated, solid crystalline particles with Tc = 92 K.


1995 ◽  
Vol 10 (5) ◽  
pp. 1307-1311 ◽  
Author(s):  
A. Martínez ◽  
J. Peña ◽  
M. Labeau ◽  
J.M. González-Calbet ◽  
M. Vallet-Regí

α-Fe2O3 thin films have been deposited on Si(111) substrates at high temperatures (600–800 °C) by the spray pyrolysis method. Four different iron(III) β-diketonates have been used as precursors in order to obtain polycrystalline films of good adherence, which have been characterized by x-ray diffraction, scanning electron microscopy, and magnetic measurements.


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