Synthesis and Characterization of Cobalt Nanoparticles Prepared by Arc Discharge Method Using an Ultrasonic Nebulizer

2018 ◽  
Vol 52 ◽  
pp. 88-101 ◽  
Author(s):  
Ahmed M. El-Khatib ◽  
Mohamed S. Badawi ◽  
Gamal D. Roston ◽  
Alaa M. Khalil ◽  
Ramy M. Moussa ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Electron Microscope ◽  
Ac Conductivity ◽  
Arc Discharge ◽  
Spherical Shape ◽  
X Ray Diffraction ◽  
Ultrasonic Nebulizer ◽  
Transmission Electron ◽  
Co Nanoparticles ◽  
Discharge Method

Magnetic cobalt nanostructured was synthesized by a two-stage method. First, a solution of cobalt precursor droplets was prepared by an ultrasonic nebulizer. Second, the arc discharge method between two electrodes in an inert gas at atmospheric pressure is used to obtain the nanostructured cobalt powder. The sample obtained was characterized by X-ray diffraction (XRD). Scanning electron microscope (SEM), High Resolution Transmission Electron Microscope (HR-TEM), UV-Vis Spectrophotometry, zeta potential (ZP) and vibrating sample magnetometer (VSM). The dielectric constant, and AC conductivity of the prepared sample was determined in the frequency range of 4 Hz to 8 MHz. The investigations showed that the Co nanoparticles prepared in this way have smaller and homogeneous nanoparticles with spherical shape morphology with good stability and unique magnetic properties as compared with the bulky one. The dielectric properties analysis shows an enhancement in the dielectric constant and the AC conductivity of the Co nanoparticles.

Microstructure of Carbon Encapsulated Superparamagnetic Co Nanoparticles

2001 ◽  
Vol 704 ◽  
Author(s):  
Xiang-Cheng Sun ◽  
J. Reyes-Gasga ◽  
X. L. Dong
Keyword(s):  
Electron Microscopy ◽  
Arc Discharge ◽  
Stacking Faults ◽  
Good Evidence ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Lattice Images ◽  
Co Nanoparticles ◽  
Discharge Method

AbstractCarbon encapsulated magnetic Co nanoparticles have been synthesized by modified arc-discharge method. Both high-resolution transmission electron microscopy (HREM) and powder x-ray diffraction (XRD) profiles reveal the presence of 8-15nm diameter crystallites coated with 1-3 carbon layers. Specially, HREM images indicate that the intimate and contiguous carbon fringe around those Co nanoparticles is good evidence for complete encapsulation by carbon shell layers. The encapsulated phases are identified as hcp (α)-Co, fcc (β)-Co and cobalt carbide (Co3C) nanocrystals by using x-ray diffraction, electron diffraction and energy dispersive x-ray analysis. However, some fcc (β)-Co particles with a significant fraction of stacking faults are observed by HREM and confirmed by means of numerical Fourier transform (FFT) of HREM lattice images. In particular, the carbon encapsulation formation and growth mechanism are also reviewed.

Thermal transport, thermomechanical, and dielectric properties of chalcogenide Se98–xAg2Inx (x = 0, 2, 4, 6) system

2014 ◽  
Vol 92 (7/8) ◽  
pp. 648-653
Author(s):  
C. Dohare ◽  
N. Mehta
Keyword(s):  
Dielectric Constant ◽  
Electron Microscope ◽  
Dielectric Loss ◽  
Thermal Transport ◽  
Microstructural Analysis ◽  
Thermomechanical Properties ◽  
X Ray Diffraction ◽  
Glassy System ◽  
Scanning Calorimetry ◽  
Transmission Electron

The present work reports a detailed study of some physical properties of some novel glasses of Se98–xAg2Inx (x = 0, 2, 4, 6) system. Measurements of thermal transport properties (i.e., thermal conductivity, κ, and thermal diffusivity, χe) have been carried out using the transient plane source technique. Specific heat measurements have been done by differential scanning calorimetry. Thermomechanical properties (i.e., Vickers hardness, Hv, and modulus of elasticity, E) have been evaluated by the indenter test. The minimal energy for formation of microvoids, Eh, and microvoids volume, Vh, of the previously mentioned glassy system are discussed in terms of microhardness, Hv. Temperature and frequency dependence of dielectric constant, ε1, and dielectric loss, ε2, for the same system were measured in the frequency (50 Hz – 1000 kHz) and temperature (303–338 K) range. The experimental results illustrate that the values of dielectric constant, ε1, and dielectric loss, ε2, are decreased with frequency and increased with temperature. The maximum barrier height, Wb, is calculated using the dielectric measurements according to the Guintini equation. The morphology and microstructural analysis of as-prepared alloys are confirmed by X-ray diffraction, scanning electron microscope, and transmission electron microscope.

Synthesis of Anatase/Brookite Mixtured TiO2 Nanoparticles by a Chimie Douce Technique

2013 ◽  
Vol 734-737 ◽  
pp. 2528-2531
Author(s):  
Yu Mei Gong ◽  
Qing Liang ◽  
Jing Guo ◽  
Hong Zhang ◽  
Fu Cheng Guan
Keyword(s):  
Electron Microscope ◽  
Anatase Phase ◽  
Spherical Shape ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Average Pore ◽  
Specific Pore Volume ◽  
Transmission Electron ◽  
Bet Method ◽  
Ft Ir

Anatase/brookite mixtured TiO2nanoparticles have been synthesized by using a two-step process through a chimie douce technique. The as-prepared powders were characterized by Fourier transform infrared (FT-IR) spectra, X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), and a nitrogen adsorption apparatus in multipoint Brunauer-Emmett-Teller (BET) method. The results indicated that the TiO2nanoparticles were composed of biphasial anatase/brookite mixtures, 38% anatase phase formed in quasi-spherical shape and 62% brookite phase formed in nanorod shape. The specific surface area, the average pore diameter, and the specific pore volume were 100.06 m2/g, 14.0 nm, and 0.561 cm3/g, respectively.

scholarly journals The optical properties of C\Mg, nano-rods produced by the explosion wire technique

2021 ◽  
Vol 2114 (1) ◽  
pp. 012041
Author(s):  
Nada. K. Hussein ◽  
S.J. Kadhem
Keyword(s):  
Image Analysis ◽  
Optical Properties ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Energy Gap ◽  
Arc Discharge ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Nano Rods

Abstract The aim of this research is to study the optical properties of carbon-magnesium plasma resulting from arc discharge with explosive wire technique, where the energy gap of each of carbon and magnesium and the carbon-magnesium bond for three values of the wire exploding current (50,75,100 amperes) was studied. It was found that the energy gap for each of carbon and magnesium decreases with increasing the current, the X-ray diffraction of magnesium and the carbon-magnesium suspension was studied, and FTIR of the carbon-magnesium suspended carbon was studied for three values of the exploding current (50, 75, 100 amperes) and the type of bonds for carbon and magnesium was determined. To obtain deeper insight about the morphology and size distribution of the nano rods obtained from the explosion of a magnesium strip in a carbon suspension images obtained from transmission electron microscope (TEM) image analysis confirmed that the formed nanomaterial is rod-shaped.

Synthesis and Characterization of Monodisperse Magnetite Nanoparticles by Hydrothermal Method

2017 ◽  
Vol 737 ◽  
pp. 367-372
Author(s):  
Apichon Watcharenwong ◽  
Yotsapon Bailuang ◽  
Puangrat Kajitvichyanukul
Keyword(s):  
Electron Microscope ◽  
Saturation Magnetization ◽  
Hydrothermal Method ◽  
Magnetite Nanoparticles ◽  
Hysteresis Loops ◽  
Spherical Shape ◽  
Pollutant Removal ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
Transmission Electron

Monodisperse nanoparticles are materials that are not agglomerate. The good characteristic of these materials is the dispersity in water, so they can better react with target pollutants. Accordingly, in this work, the monodisperse magnetite nanoparticles with the superparamagnetic property were synthesized and characterized. The hydrothermal method with the iron compound and polymer as precursors was conducted. The magnetic nanoparticles were characterized by several techniques including X-ray diffraction, field emission scanning electron microscope, transmission electron microscope, and vibrating sample magnetometer. The saturation magnetization (Ms) value, the coercivity (Hc), and the retentivity (Mr) were measured to demonstrate the paramagnetic behavior of the monodisperse magnetite nanoparticles. The results showed that the Fe3O4 nanoparticle were obtained at 200 °C for 16 h. The particles are monodispersed with the size approximately in the range of 60 - 250 nm as confirmed by FE-SEM and TEM images. These are the single grain and had the spherical shape similar to a blackberry. The saturation magnetization of 17.287 emu/g and ratio of retentivity to saturation magnetization (Mr/Ms) characterized the squareness of the hysteresis loops was 0.03653. It can be indicated that the Fe3O4 nanoparticles had superparamagnetic behavior. This property of Fe3O4 nanoparticles can draw pollutants to absorb on the surface of these nanomaterials. Then adsorbed pollutants can be easily removed by separating the Fe3O4 materials from water. This technique can be applied further in water treatment and pollutant removal.

A Study on the Oxygen Percent and the Crystalline Structure of Silver Nanoparticles Obtained by Electrochemical Method

2018 ◽  
Author(s):  
Sara Sadat Parhizgar ◽  
S. Sibouyeh
Keyword(s):  
Silver Nanoparticles ◽  
Crystalline Structure ◽  
Arc Discharge ◽  
Water Medium ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Plasma Arc Discharge ◽  
Silver Nps ◽  
Discharge Method ◽  
Air Medium

In this paper silver nanoparticles (NPs) which are synthesized by a simple plasma arc discharge method, that is a kind of electrochemical methods, are examined. The method is very simple and silver NPs are obtained very fast by means of two polished silver plates and electrochemical cell. The effects of changing some terms of the experiment including using Hydrogen peroxide (H2O2), temperature and the medium of experiment on oxygen percent and crystalline structure of silver NPs have been studied by transmission electron microscopy, UV-visible spectrophotometery, and X-ray diffraction. Water medium gets larger nanoparticles with less oxygen content compare to air medium. The size of synthesized nanoparticles become smaller and they also become more spherical by using H2O2 in air medium. In water medium, the size and concentration of the silver crystallite increase by temperature growth and adding H2O2  respectively. 

scholarly journals Effects of Increasing Electrodes on CNTs Yield Synthesized by Using Arc-Discharge Technique

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Samy Yousef ◽  
A. Khattab ◽  
T. A. Osman ◽  
M. Zaki
Keyword(s):  
Electron Microscope ◽  
Arc Discharge ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Pure Graphite ◽  
Transmission Electron ◽  
Multiple Electrodes ◽  
Fully Automatic ◽  
Single Plasma

A new design of fully automatic system was built up to produce multiwalled carbon nanotube (MWCNT) using arc discharge technique in deionized water and extra pure graphite multiple electrodes (99.9% pure). The goal of the experimental research is to determine the yield of CNT in two different cases: (a) single plasma electrodes and (b) multiplasma electrodes, particularly 10 electrodes. The experiments were performed at constant parameters (75 A, 238 V). The obtained CNT was examined by scanning electron microscope (SEM), transmission electron microscope (HRTEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The results showed that the produced CNT is of type MWCNT, with a diameter of 5 nm, when using multiplasma electrodes and 13 nm when using single plasma electrodes. The yield of MWCNT was found to be 320% higher in case of comparing multielectrodes to that of single plasma electrodes. Under the experimental test conditions, a yield of 0.6 g/hr soot containing 40% by mass nanotube was obtained in case of single plasma electrodes and above 60% in case of multiplasma electrodes.

Synthesis and Analysis of Mn3O4@Graphene Nanocomposites for Supercapacitors

2017 ◽  
Vol 26 (1) ◽  
pp. 096369351702600 ◽  
Author(s):  
Mingfu Zhu ◽  
Ruimin Fu
Keyword(s):  
Arc Discharge ◽  
Electrochemical Behaviour ◽  
Electronic Conduction ◽  
Graphene Sheets ◽  
X Ray Diffraction ◽  
Graphene Nanocomposites ◽  
X Ray ◽  
Transmission Electron ◽  
Morphology And Structure ◽  
Discharge Method

An easy arc discharge method was developed to synthesize nanocomposites composed of Mn3O4 nanoparticles loaded on graphene sheets. The morphology and structure of the obtained nanocomposites were analysed via X-ray diffraction, Raman spectroscopy, and transmission electron microscopy. The electrochemical behaviour of the product was evaluated via cyclic voltammetry and alternating current impedance. Results showed that Mn3O4 was dispersed homogeneously on the surface of graphene. The supercapacitor constructed by graphene/Mn3O4 as the positive electrode showed both high capacitance and good electronic conduction, which may lead to the development of nanocomposites with great potential for applications in biosensors and electrode material analysis.

ARC Discharge for the Synthesis of Monoclinic Ga2O3 Nanowires

1999 ◽  
Vol 581 ◽  
Author(s):  
Young Chul Choi ◽  
Dong Jae Bae ◽  
Seung Mi Lee ◽  
Young Soo Park ◽  
Young Hee Lee ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Arc Discharge ◽  
Average Diameter ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Crystalline Nature ◽  
Twin Defects ◽  
Xrd Patterns ◽  
Gallium Oxides ◽  
Ft Raman

ABSTRACTMonoclinic gallium oxide (β-Ga2O3) nanowires were catalytically synthesized by electric arc discharge of GaN powders mixed with a small amount (less than 5 %) of transition metals under a pressure of 500 Torr (80 %-Ar + 20 %-O2). Scanning electron microscope (SEM) and high-resolution transmission electron microscope (HRTEM) images showed that the average diameter of the wires were about 30 nm and their lengths were as long as up to one hundred micrometer, resulting in extremely large aspect ratio. Fourier diffractogram was indicative of single crystalline nature of the β-Ga2O3 wire. HRTEM image also showed β-Ga2O3 with twin defects at the center of the wire which might play as nucleation seeds. Both X-ray diffraction (XRD) patterns and FT-Raman spectra of the wires identified the observed nanowires as monoclinic crystalline gallium oxides.

scholarly journals A Study on the Oxygen Percent and the Crystalline Structure of Silver Nanoparticles Obtained by Electrochemical Method

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
Sara Sadat Parhizgar ◽  
S. Sibouyeh
Keyword(s):  
Silver Nanoparticles ◽  
Crystalline Structure ◽  
Arc Discharge ◽  
Water Medium ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Plasma Arc Discharge ◽  
Silver Nps ◽  
Discharge Method ◽  
Air Medium

In this paper silver nanoparticles (NPs) which are synthesized by a simple plasma arc discharge method, that is a kind of electrochemical methods, are examined. The method is very simple and silver NPs are obtained very fast by means of two polished silver plates and electrochemical cell. The effects of changing some terms of the experiment including using Hydrogen peroxide (H2O2), temperature and the medium of experiment on oxygen percent and crystalline structure of silver NPs have been studied by transmission electron microscopy, UV-visible spectrophotometery, and X-ray diffraction. Water medium gets larger nanoparticles with less oxygen content compare to air medium. The size of synthesized nanoparticles become smaller and they also become more spherical by using H2O2 in air medium. In water medium, the size and concentration of the silver crystallite increase by temperature growth and adding H2O2  respectively. 

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