Compositions and Particle Sizes of (RE)Ba2Cu3O7-X Superconductor Powders Synthesized by the Solution Combustion Technique

2012 ◽  
Vol 488-489 ◽  
pp. 286-290 ◽  
Author(s):  
Oratai Jongprateep ◽  
Pimsiri Tangbuppa ◽  
Nattawan Manasnilobon
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Compositional Analysis ◽  
Industrial Applications ◽  
Average Particle ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Solution Combustion ◽  
Superconducting Compounds ◽  
Combustion Technique

Superconducting compounds (RE) Ba2Cu3O7-x (RE = rare earth such as Y, Er, Sm and Nd) can be exploited in various industrial applications such as cables, electric motors and energy storage systems. The project aimed at synthesizing fine-particle YBa2Cu3O7-x, ErBa2Cu3O7-x, SmBa2Cu3O7-x and NdBa2Cu3O7-x, powders with compositions suitable for the applications. Solution combustion technique was employed in the synthesis, using urea as fuel. Compositional analysis obtained from x-ray diffraction indicated that the as-synthesized powders contained the desired (RE)Ba2Cu3O7-x (RE123) superconducting phase and impurities, including (RE)2BaCuO5 (RE211), BaCO3 and Ba(NO3)2. However, majority of the impurities were eliminated when the powders were calcined at 900°C. Only (RE)Ba2Cu3O7-x (RE123) and (RE)2BaCuO5 (RE211) phases remained after calcination. Results from scanning electron microscope showed that the as-synthesized powders obtained from the solution combustion technique had relatively small particles with average particle size of 0.67 micrometers, while the calcined powders exhibited coarsening effects with average particle size of 4.4 micrometers.

Effects of Dissolving Agents on Particle Size Reduction of Titanium Dioxide Synthesized by Solution Combustion Technique

2016 ◽  
Vol 690 ◽  
pp. 236-239
Author(s):  
Oratai Jongprateep ◽  
Rachata Puranasamriddhi
Keyword(s):  
Particle Size ◽  
Titanium Dioxide ◽  
Sulfuric Acid ◽  
Nitric Acid ◽  
Average Particle Size ◽  
Average Particle ◽  
Particle Sizes ◽  
Solution Combustion ◽  
Initial Reagent ◽  
Combustion Technique

High photocatalytic activity of nanoparticulate titanium dioxide has attracted worldwide attention. Synthesis techniques of the nanoparticles, however, often require high energy supply or costly initial reagents. Solution combustion technique is an energy-effective technique capable of synthesizing nanosized titanium powders. This research aimed at utilizing a less expensive initial reagent in synthesis of nanoparticulate titanium dioxide by the solution combustion technique. The research also examined effects of dissolving agents on chemical composition and particle sizes of the synthesized powders. A low-cost initial reagent, titanium dioxide with average particle size of 154 nanometers, was dissolved in sulfuric acid or dispersed in nitric acid prior to the combustion. Experimental results revealed that the pure anatase phase titanium dioxide was successfully obtained in powders prepared from both sulfuric acid and nitric acid. The average particle size of the powder prepared from sulfuric acid was 77 nanometers, while that of the powder prepared from nitric acid was 117 nanometers. The difference in particle sizes was attributed to solubility of the initial reagent in the acid. Complete solution of initial reagent in sulfuric acid was the main factor attributed to finer particle size.

scholarly journals Thermal, Structural, and Physical Properties of Freeze Dried Tropical Fruit Powder

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
K. A. Athmaselvi ◽  
C. Kumar ◽  
M. Balasubramanian ◽  
Ishita Roy
Keyword(s):  
Particle Size ◽  
Physical Properties ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Tropical Fruit ◽  
X Ray ◽  
Freeze Dried ◽  
Fruit Powder ◽  
Lcr Meter

This study evaluates the physical properties of freeze dried tropical (guava, sapota, and papaya) fruit powders. Thermal stability and weight loss were evaluated using TGA-DSC and IR, which showed pectin as the main solid constituent. LCR meter measured electrical conductivity, dielectric constant, and dielectric loss factor. Functional groups assessed by FTIR showed presence of chlorides, and O–H and N–H bonds in guava, chloride and C–H bond in papaya, and chlorides, and C=O and C–H bonds in sapota. Particle size and type of starch were evaluated by X-ray diffraction and microstructure through scanning electronic microscopy. A semicrystalline profile and average particle size of the fruit powders were evidenced by X-ray diffraction and lamellar/spherical morphologies by SEM. Presence of A-type starch was observed in all three fruits. Dependence of electric and dielectric properties on frequency and temperature was observed.

scholarly journals Synthesis of MgO Nanoparticles by Solvent Mixed Spray Pyrolysis Technique for Optical Investigation

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
K. R. Nemade ◽  
S. A. Waghuley
Keyword(s):  
Particle Size ◽  
Spray Pyrolysis ◽  
Spray Pyrolysis Technique ◽  
Average Particle Size ◽  
Band Gap Energy ◽  
Average Particle ◽  
Optical Investigation ◽  
X Ray Diffraction ◽  
Mgo Nanoparticles ◽  
Electron Microscope Analysis

Solvent mixed spray pyrolysis technique has attracted a global interest in the synthesis of nanomaterials since reactions can be run in liquid state without further heating. Magnesium oxide (MgO) is a category of the practical semiconductor metal oxides, which is extensively used as catalyst and optical material. In the present study, MgO nanoparticles were successfully synthesized using a solvent mixed spray pyrolysis. The X-ray diffraction pattern confirmed the formation of MgO phase with an excellent crystalline structure. Debye-Scherrer equation is used for the determination of particle size, which was found to be 9.2 nm. Tunneling electron microscope analysis indicated that the as-synthesized particles are nanoparticles with an average particle size of 9 nm. Meanwhile, the ultraviolet-visible spectroscopy of the resulting product was evaluated to study its optical property via measurement of the band gap energy value.

Frequency dependence and fuel effect on optical properties of nano TiO2-based structures

2016 ◽  
Vol 30 (18) ◽  
pp. 1650247 ◽  
Author(s):  
Mahdi Ghasemifard ◽  
Misagh Ghamari ◽  
Meysam Iziy
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Average Particle Size ◽  
Combustion Method ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Nano Tio2 ◽  
Transmission Electron ◽  
Auto Combustion ◽  
Xrd Patterns

TiO2-(Ti[Formula: see text]Si[Formula: see text]O2 nanopowders (TS-NPs) with average particle size around 90 nm were successfully synthesized by controlled auto-combustion method by using citric acid/nitric acid (AC:NA) and urea/metal cation (U:MC). The structure of powders was studied based on their X-ray diffraction (XRD) patterns. The XRD of TS-NPs shows that rutile and anatase are the main phases of TS-NPs for AC:NA and U:MC, respectively. Particle size and histogram of nanopowders were characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). Optical properties of TS-NPs were calculated by Fourier transform infrared spectroscopy (FTIR) and Kramers–Kroning (KK) relation. Plasma frequencies of TS-NPs obtained from energy loss functions depend on fuels as a result of changes in crystal structure, particle size distribution, and morphology.

Effect of Surfactant on the Preparation of Nano-powder for Yb Doping Laser Transparent YAG Ceramic

2013 ◽  
Vol 32 (5) ◽  
pp. 511-515 ◽  
Author(s):  
Xiao Guo Cao ◽  
Jia Wang ◽  
Qi Bai Wu ◽  
Hai Yan Zhang
Keyword(s):  
Particle Size ◽  
Polyethylene Glycol ◽  
Average Particle Size ◽  
Ammonium Bicarbonate ◽  
Spherical Particles ◽  
Precipitation Method ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Nano Powder ◽  
Co Precipitation

AbstractYb:YAG transparent ceramic nano-powder was prepared by chemical co-precipitation method, with ammonium bicarbonate as the precipitant and polyethylene glycol as surfactant. The addition of polyethylene glycol can reduce the agglomeration and particle size of the prepared Yb:YAG powder. The morphology, thermal stability and phase structure of Yb:YAG nano-powder were charactered by scanning electron microscopy (SEM), thermogravimetry and differential thermal analysis (TG-DTA), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy. The results show that well-crystallized nano-powder was obtained by calcining the precursors at 900 °C for 3 h. The average particle size of Yb:YAG powder is about 100–200 nm. When the volume amount of polyethylene glycol is 2.0%, well-dispersed Yb:YAG powder with spherical particles of 100 nm diameter was obtained.

Preparation and Characterization of Gold Nanoparticles in the Presence of Citrate and Soybean Seed Extract in an Acidic Conditions

Drug Research ◽  
2017 ◽  
Vol 67 (05) ◽  
pp. 266-270 ◽  
Author(s):  
Ebrahim Izadi ◽  
Ali Rasooli ◽  
Abolfazl Akbarzadeh ◽  
Soodabeh Davaran
Keyword(s):  
Particle Size ◽  
Gold Nanoparticles ◽  
Size Distribution ◽  
Average Particle Size ◽  
Soybean Seed ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Soybean Extract ◽  
Average Size

AbstractThrough the present study, an eco-friendly method was used to synthesize the gold nanoparticles (GNPs) by using the sodium citrate and extract of the soybean seed as reducing the agents at PH 3. X-Ray diffraction (XRD) method was used to evaluate the crystal structure of as-synthesized NPs and it’s revealed that this method leads to well crystallized GNPs. In order to determine the particle size and their distribution, field emission scanning microscopy (FE-SEM) and dynamic light scattering (DLS) were used. The results showed that, the average particle size distribution of synthesized GNPs in solutions containing of the soybean extract and 1% citrate at PH 3 is about 109.6 and 140.9 nm, respectively. Also, we find that the average size of GNPs is 40 and 33 nm from solutions of citrate and soybean extract, respectively. It was concluded that using the extract of soybean seeds as reducing agent can lead to GNPs with small size and narrow size distribution.

scholarly journals Synthesis and characterization of ZnTe nanoparticles

2016 ◽  
Vol 17 (1) ◽  
pp. 1-3 ◽  
Author(s):  
Sujan Dhungana ◽  
Bhoj Raj Paudel ◽  
Surendra K. Gautam
Keyword(s):  
Particle Size ◽  
Field Effect Transistors ◽  
Average Particle Size ◽  
Precursor Solution ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Zinc Compounds ◽  
Transmission Electron

In this work, we report the ZnTe semiconductor nanoparticles (NPs) prepared by aqueous chemical precipitation method using the tellurium precursor solution with different zinc compounds. Three batches of ZnTe NPs were synthesized to study the effect of dilution on the size and phase purity of ZnTe. The influence of source compounds and concentrations of the size and structure of NPs were studied. ZnTe NPs have great applications as field-effect transistors and photodetectors. The existing controversy regarding the crystalline structure of ZnTe NPs, whether it is cubic or hexagonal, has been resolved using X-ray Diffraction (XRD) data. The ZnTe NPs possess cubic structure, which is also confirmed by Electron Diffraction (ED) pattern. The average particle size determined from XRD data with the help of Debye-Scherrer equation is about 6 nm. The particle size can be further verified by Transmission Electron Microscopy (TEM) studies.  

scholarly journals Dielectric properties of BNT-xBT prepared by hydrothermal process

2017 ◽  
Vol 07 (03) ◽  
pp. 1750019 ◽  
Author(s):  
Natheer B. Mahmood ◽  
Emad K. Al-Shakarchi
Keyword(s):  
Strong Dependence ◽  
Average Particle Size ◽  
Hydrothermal Process ◽  
Industrial Applications ◽  
Rhombohedral Structure ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Depolarization Temperature ◽  
X Ray ◽  
Ceramic Disc

The BNT ceramic sample might be a good replacement for PZT piezoelectric in industrial applications, especially in energy harvesting from crystal vibrations. In order to enhance the performance of BNT ceramic, the solid solution was chosen by substitution with Ba[Formula: see text] at Morphtropic Phase Boundary (MPB). The BNT-[Formula: see text]BT powders with [Formula: see text], 0.07, 0.06 and 0 were prepared by the hydrothermal method with average particle size (65–150[Formula: see text]nm) at (90[Formula: see text]C/72[Formula: see text]h). The ceramic disc was sintered at (1150[Formula: see text]C/4[Formula: see text]h) and showed excellent relative density of about 96%. The results of X-ray diffraction (XRD) confirmed the MPB for [Formula: see text] and 0.07, while the BNT had a rhombohedral structure and BT had a tetragonal structure. The dielectric measurements showed that BNT, BNT-7BT, BNT-6BT behave as the relaxator ferroelectric and showed a strong dependence on frequency, especially in the MPB region while BT behaves as a normal ferroelectric. Both the Curie temperature and depolarization temperature decrease at the MPB region and showed strong dependency on frequency.

Determination of Latex Particle Size Distributions by Fractional Creaming with Sodium Alginate

1961 ◽  
Vol 34 (2) ◽  
pp. 433-445 ◽  
Author(s):  
E. Schmidt ◽  
P. H. Biddison
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Sodium Alginate ◽  
Mass Distribution ◽  
Average Particle Size ◽  
Average Particle ◽  
Particle Sizes ◽  
Size Distributions ◽  
Particle Size Distributions

Abstract Knowledge of mass distribution of particle sizes in latex is very important to the latex technologist. Therefore, it is desirable to have available a simple method for the determination of mass distribution of particle sizes. This paper presents a method, based on fractional creaming of latex with sodium alginate, which can be used in any laboratory without special equipment. The method is particularly advantageous for analyzing latexes of very wide particle size distributions. When analyzed with an electron microscope, these latexes require counting a very large number of particles. McGavack found that partial creaming of normal hevea latex with ammonium alginate gives concentrates of larger average particle size than the original latex. He found that the average particle size in the cream approaches that of the original latex as the amount of creaming agent is increased. In a previous paper from this laboratory, Schmidt and Kelsey demonstrated that the phenomenon of fractionation according to particle size with increasing amounts of creaming agent is applicable in a wide variety of anionic latex systems and in colloidal silica. Their results indicated also the existence of a quantitative relationship, independent of the nature of the dispersed particles, between the concentration of creaming agent and size of creamed particles. Maron confirmed fractionation with respect to particle size as a consequence of partial creaming with alginate. He showed that the mass average particle sizes of fractions, determined optically, cumulate to that of the original latex. Although the previous paper by Schmidt and Kelsey implied the basic concept of a method of determining particle size distribution by fractional creaming, it was not exploited at that time. In order to adapt the fractional creaming phenomenon to a quantitative method for particle size determination, we required a more precise knowledge of the relation between creaming agent concentration and size of particles creamed. It was proposed to establish this relationship with the aid of the electron microscope. Various factors influencing the creaming of latex, such as polymer concentration, electrolyte, soap content, and variability of the creaming agent, had to be considered in standardizing the creaming procedure.

Study on Nickel Nanopowders Prepared by Arc Plasma

2013 ◽  
Vol 734-737 ◽  
pp. 1555-1558
Author(s):  
Cong Hua Hou ◽  
Yun Ge Chen
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Barometric Pressure ◽  
Constant Current ◽  
Average Particle ◽  
Face Centered Cubic ◽  
Arc Plasma ◽  
X Ray Diffraction ◽  
Current Voltage ◽  
Face Centered

In order to prepare the nickel nano-metal with high purity and uniform particle size , the arc plasma method was used. The nano-Ni was got under a constant current , voltage , barometric pressure, hydrogen and argon gas . The nickel nanopowders were tested through the Scan Electron Microscope (SEM ), X-ray diffraction (XRD), Laser Sizer Analysis (LSA). The results indicated that the feature of the nickel nanopowders were mainly spherical, smooth surface. The nickel powder particle distribute from 40 to 80nm. And average particle size is 60nm. Nanocrystals had a better internal crystallinity. The crystal structure is face-centered cubic FCC structure, the same as ordinary nickel nanoparticles .

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