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.

Single-Crystal Iron Nanowire Arrays

2007 ◽  
Vol 121-123 ◽  
pp. 17-20 ◽  
Author(s):  
Yue Ling Sun ◽  
Ying Dai ◽  
L.Q. Zhou ◽  
Wen Chen
Keyword(s):  
Electron Microscope ◽  
Single Crystal ◽  
Hysteresis Loops ◽  
Nanowire Arrays ◽  
X Ray Diffraction ◽  
Easy Magnetization ◽  
Transmission Electron ◽  
Iron Nanowires ◽  
Xrd Patterns ◽  
Different Diameters

Highly ordered single-crystal iron nanowire arrays with different diameters have been fabricated in anodic aluminum oxide (AAO) templates by DC electrodeposition method. The Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) show that the iron nanowires are highly uniform and exhibit a single crystal structure. The X-ray diffraction (XRD) patterns of iron nanowire arrays indicate that most of the iron nanowire arrays have the obvious preferred orientation along the [200] direction. From the hysteresis loops of the iron nanowires, it reveals that the easy magnetization axes of nanowire arrays are along the long axis. The sample with smaller diameter (d=35nm) has a high square ratio (up to 98%) and a high coercive filed (1265Oe) when the external magnetic field is applied along axis of the nanowires. When the diameter decreases, the square ratio and the coercive field increase due to the single-domain structure and the strong shape anisotropy in the smaller diameter nanowire arrays.

Improvement of the Crystallinity of La2CuO4 Nanoparticles Using the Vacuum Treatment

2021 ◽  
Vol 1028 ◽  
pp. 44-49
Author(s):  
Anita Eka Putri ◽  
Suci Winarsih ◽  
Budhy Kurniawan ◽  
Dicky Rezky Munazat ◽  
Dhawud Sabilur Razaq ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Vacuum Treatment ◽  
Vacuum Pressure ◽  
Morphological Properties ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Xrd Patterns

Nanoparticles of La2CuO4 (LCO) with different particles and crystallite size have been synthesized by the sol-gel method. The samples have been sintered at 600, 650, and 700°C. The sintering process have been performed in atmospheric pressure and vacuum pressure. The structural and morphological properties of the samples have been investigated by the X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Transmission Electron Microscope (TEM). The XRD patterns of the samples have shown that all samples crystallize in orthorhombic structure with Bmab space group. Additionally, Rietveld refinement process have shown that higher sintering temperature, as well sintering process under vacuum pressure, can improve both phase purity and the crystallinity of the samples. SEM and TEM results have also shown that higher sintering temperature results in a sample with larger particle size.

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.

scholarly journals Facile Synthesis of Template-Induced SnO2Nanotubes

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Yang Liu ◽  
Yang Jiao ◽  
Fengyu Qu ◽  
Lihong Gong ◽  
Xiang Wu
Keyword(s):  
Electron Microscope ◽  
Large Scale ◽  
Average Diameter ◽  
X Ray Diffraction ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Transmission Electron ◽  
Experimental Parameters ◽  
Mild Temperature ◽  
Temperature Time

Large scale SnO2nanotubes are successfully obtained by a facile hydrothermal method at a mild temperature. The morphologies and the microstructures of the as-synthesized SnO2products are characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). The average diameter of the nanotubes is about 100 nm. The phase and composition of the as-obtained products are investigated by X-ray diffraction (XRD). A series of comparison experiments were conducted by varying the experimental parameters, such as temperature, time, and the amount of the alkali, to study the formation mechanism of SnO2nanotubes.

THE ASSEMBLY OF CHAIN-LIKE Ni ARRAYS UNDER MAGNETIC FIELD AND ITS ENHANCED PROPERTIES

2010 ◽  
Vol 09 (05) ◽  
pp. 543-547 ◽  
Author(s):  
JUN WANG ◽  
SHIHE CAO ◽  
SIHUA XIA ◽  
NING GAN
Keyword(s):  
Magnetic Field ◽  
Electron Microscope ◽  
External Magnetic Field ◽  
Self Assembly ◽  
Hydrothermal Process ◽  
X Ray Diffraction ◽  
Vertical Arrays ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Facile Hydrothermal Process

Chain-like nickel arrays assembled from magnetic Ni spheres were successfully prepared through a facile hydrothermal process at 200°C under a 0.25 T external magnetic field. The external magnetic field is strongly believed to be the driving force of the self-assembly. The sample was highly crystalline as confirmed by the X-ray diffraction (XRD) patterns. The scanning electron microscope (SEM) and transmission electron microscope (TEM) images show that all Ni spheres are closely interconnected to form chains, with ~ 950 nm in diameter and ~ 1 cm in length, which arrange into vertical arrays on the silicon substrate. The coercivity and remnant magnetization ratio of the sample, 670 Oe and 0.612, respectively, are substantially higher than for the sample prepared without an applied external magnetic field (68 Oe and 0.336). Such enhancements can be attributed to their novel superstructure, shape anisotropy, reduced demagnetization factor, etc. This process can be used to fabricate large arrays of uniform chains of magnetic materials and modulate their magnetic properties.

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.

Magnetic Properties of Mg0.4Ca0.6Fe2O4 Nanoparticles Synthesized by Sol-Gel Method for Hyperthermia Treatment

2014 ◽  
Vol 631 ◽  
pp. 193-197
Author(s):  
A.M. Escamilla-Pérez ◽  
D.A. Cortés-Hernández ◽  
J.M. Almanza-Robles ◽  
D. Mantovani ◽  
P. Chevallier
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Average Diameter ◽  
X Ray Diffraction ◽  
Hyperthermia Treatment ◽  
X Ray ◽  
Transmission Electron ◽  
Heat Treated ◽  
Different Temperatures ◽  
Xrd Patterns

Powders of Mg0.4Ca0.6Fe2O4were prepared by sol-gel using ethylene glycol and Mg, Ca and Fe nitrates as starting materials. Those powders were heat treated at different temperatures (300, 400, 500 and 600 °C) for 30 min. The materials obtained were characterized by X-ray diffraction (XRD) and vibrating sample magnetometry (VSM). The Ca-Mg ferrite with the most appropriate magnetic properties was further analyzed by transmission electron microscopy (TEM). The heating capability of the nanoferrites was also tested via magnetic induction. The XRD patterns of these Ca-Mg ferrites showed a cubic inverse spinel structure. Furthermore, neither traces of hematite nor orthorhombic Ca ferrite phases were detected. Moreover, all the Ca-Mg ferrites are superparamagnetic and the particle size distribution of these Ca-Mg magnetic nanoparticles exhibits an average diameter within the range of 10-14 nm. The needed temperature for hyperthermia treatment was achieved at around 12 min.

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.

scholarly journals Tunable synthesis of platinum nanoparticles by EtOH reduction in presence of poly (vinylpyrrolidone)

2015 ◽  
Vol 50 (2) ◽  
pp. 87-92 ◽  
Author(s):  
MS Rahman ◽  
S Akhter ◽  
KN Ahmed ◽  
MS Rahman ◽  
RK Saha ◽  
...  
Keyword(s):  
Platinum Nanoparticles ◽  
Average Molecular Weight ◽  
Average Diameter ◽  
Organic Polymer ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
Transmission Electron ◽  
Uv Visible ◽  
Xrd Patterns ◽  
Growth Formation

Monodispersed platinum nanoparticles (Pt-NPs) with an average diameter dTEM 3.1±1.0 nm were synthesized by EtOH reduction method in the presence of an organic polymer poly (vinylpyrrolidone) (PVP) with an average molecular weight of 40,000. Using this particles as seed, size tunable Pt-NPs of dTEM 3.1±1.0 nm to 5.7±1.6 nm with sufficient monodispersity were synthesized by multiple step seeding growth. Formation of Pt-NPs was confirmed by the UV-visible absorption spectra. Transmission electron micrographs (TEM) and powder X-ray diffraction (XRD) patterns confirmed that the particles were single crystalline with fcc crystal geometry.Bangladesh J. Sci. Ind. Res. 50(2), 87-92, 2015

High photoelectric PPV/PVA/Ag composite nanofibers by co-electrospinning

2015 ◽  
Vol 35 (7) ◽  
pp. 689-697 ◽  
Author(s):  
Yang Gao ◽  
Zhiyao Sun ◽  
Liguo Sun ◽  
Cheng Wang ◽  
Shuhong Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Composite Nanofibers ◽  
Average Diameter ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Photoelectric Properties ◽  
Transmission Electron ◽  
Face Centered ◽  
Xrd Patterns

Abstract Poly(phenylene vinylene)/polyvinyl alcohol/Ag (PPV/PVA/Ag) composite nanofibers with excellent photoelectric properties were prepared by coaxial electrospinning using PPV/PVA as the shell and Ag nanoparticles (NPs) as the core, Ag NPs aqueous solution was prepared by the reduction method. The results of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that Ag NPs are of a face-centered cubic structure, with an average diameter of 46 nm and the composite nanofibers have uniform and continuous morphology. With increasing Ag content, the diameters of the composite nanofibers decreased from 653 nm to 250 nm. The X-ray diffraction (XRD) patterns verified that in the composite nanofibers, the Ag NPs are not transformed. In the photoluminescence spectra, the PPV/PVA/Ag composite nanofibers presented red-shift compared with PPV/PVA nanofibers. Under illumination, the as-prepared PPV/PVA/Ag composite nanofibers exhibited relatively high photocurrent intensity.

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