SYNTHESIS OF YTTRIA-STABILIZED CUBIC ZIRCONIA NANOCRYSTALS BY ULTRASONIC–MICROWAVE ROUTE

NANO ◽  
2010 ◽  
Vol 05 (05) ◽  
pp. 271-277 ◽  
Author(s):  
JIAN-DONG WANG ◽  
CHONG-XIAO LUO ◽  
JIN-KU LIU ◽  
YI LU ◽  
GUANG-MING LI
Keyword(s):  
Average Particle Size ◽  
Degree Of Crystallinity ◽  
Average Particle ◽  
Stabilized Zirconia ◽  
Uniform Size ◽  
X Ray ◽  
Microwave Assisted ◽  
Transmission Electron ◽  
High Degree ◽  
Microwave Assisted Method

The yttria-stabilized zirconia (YSZ) nanocrystals with uniform size, high purity, and high degree of crystallinity, were prepared by ultrasonic–microwave-assisted method. The structure, optical properties and morphologies of YSZ nanocrystals were characterized by X-ray powder diffraction (XRD), Raman spectroscopy, UV–vis absorption, scanning electron microscope (SEM) and transmission electron microscopy (TEM). The SEM and TEM images of the YSZ nanocrystals indicate that the product is a mono-dispersion structure with an average particle size of about 25 nm.

Synthesis of Fe2O3/C Nanocomposite Using Microwave Assisted Calcination Method

2014 ◽  
Vol 896 ◽  
pp. 100-103 ◽  
Author(s):  
Anggi Puspita Swardhani ◽  
Ferry Iskandar ◽  
Abdullah Mikrajuddin ◽  
Khairurrijal
Keyword(s):  
Crystallite Size ◽  
Average Particle Size ◽  
Molar Ratio ◽  
Average Particle ◽  
X Ray ◽  
Molar Ratios ◽  
Microwave Assisted ◽  
Chloride Hexahydrate ◽  
Calcination Method ◽  
Scherrer Method

Fe2O3/C nanocomposites were successfully synthesized using microwave assisted calcination method. Ferric (III) chloride hexahydrate (FeCl36H2O), sodium hydroxide (NaOH), and dextrose monohydrate (C6H12O6H2O) were used as precursors. A microwave oven of 2.445 GHz with a power of 600 W for 20 minutes was employed during the syntheses. Calcination was performed in a simple furnace at 350 °C for 30 min. The molar ratio of C:Fe is the only process parameter. From Scanning Electron Microscope images, the average particle size were 199 nm and 74 nm for the samples with molar ratio of C:Fe of 1:2 and 1:1, respectively. X-ray diffractometer spectra showed that the obtained samples have γ-Fe2O3 (maghemite) crystal structure. Using the Scherrer method, the crystallite size were 61.7, 58.8, 52.5, and 48.8 nm for the samples with the molar ratios of C:Fe of 1:3, 1:2, 1:1, and 2:1, respectively. It means that the crystallite size of the nanocomposite decreases with the increase of the molar ratio of carbon to iron (C:Fe). The Brunauer-Emmett-Teller characterization showed that the surface area as high as 255.6 m2/g is achieved by of the Fe2O3/C nanocomposite with the molar ratio of C:Fe of 1:1.

Heteroepitaxial Growth of Ba0.5Sr0.5TiO3/SrRuO3 on YSZ/Si by Off-Axis Sputtering

1994 ◽  
Vol 361 ◽  
Author(s):  
S.Y. Hou ◽  
J. Kwo ◽  
R.K. Watts ◽  
J.-Y. Cheng ◽  
R.J. Cava ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Degree Of Crystallinity ◽  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Dielectric Constant And Loss ◽  
Bst Films ◽  
High Degree ◽  
Room Temperature Dielectric Constant

ABSTRACTWe demonstrate an epitaxial heterostructure of Ba0.5Sr0.5 TiO3/SrRuO3/YSZ on Si for potential charge storage applications. The dielectric Ba0.5Sr0.5TiO3 (BST) and conductive oxide SrRuO3 are both grown (110) oriented on YSZ (100) buffered Si by 90° off-axis sputtering. These films showed a high degree of crystallinity with minimal interdiffusion at the interfaces as examined by X-ray diffraction, Rutherford backscattering spectroscopy, and cross-section transmission electron microscopy. The in-plane epitaxial alignment of the films is BST/SRO 〈111〉 // YSZ 〈110〉 with a four-fold degeneracy. The dielectric constant and loss tangent of the epi-BST films are 360 and 0.01 at 10 kHz. The leakage current density is < 4×10∼−7 A/cm2 at 1 V. The room temperature dielectric constant (ε) of the BST films shows a roll-off in the 1–10 MHz range. This is attributed to the existence of a series resistance in the measurement circuit, which likely arises from the SrRuO3 electrode.

Biosynthesis and Characterization of Copper Nanoparticles Using a Bioflocculant Extracted from Alcaligenis faecalis HCB2

2019 ◽  
Vol 11 (11) ◽  
pp. 1064-1070 ◽  
Author(s):  
Nkosinathi G. Dlamini ◽  
Albertus K. Basson ◽  
V. S. R. Rajasekhar Pullabhotla
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Copper Nanoparticles ◽  
Average Particle Size ◽  
Thermo Gravimetric Analysis ◽  
Average Particle ◽  
Gravimetric Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir

Bioflocculant from Alcaligenis faecalis HCB2 was used in the eco-friendly synthesis of the copper nanoparticles. Nanoparticles were characterized using a scanning electron microscope (SEM), transmission electron microscopy (TEM), UV-visible spectroscopy, thermo gravimetric analysis (TGA) and Fourier Transform Infrared Spectroscopy (FT-IR). The transmission electron microscopy images showed close to spherical shapes with an average particle size of ∼53 nm. Energy-dispersive X-ray spectroscopy analysis confirmed the presence of the Cu nanopartilces and also the other elements such as O, C, P, Ca, Cl, Na, K, Mg, and S originated from the bioflocculant. FT-IR results showed the presence of the –OH and –NH2 groups, aliphatic bonds, amide and Cu–O bonds. Powder X-ray diffraction peaks confirmed the presence of (111) and (220) planes of fcc structure at 2 of 33° and 47° respectively with no other impurity peaks.

Synthesis of NixFe3-xO4 Nanoparticles by Microwave-Assisted Coprecipitation and their Application in Viscosity Reduction of Heavy Oil

2013 ◽  
Vol 737 ◽  
pp. 204-208 ◽  
Author(s):  
Mohamad Insan Nugraha ◽  
Prawistin Noorlaily ◽  
Mikrajuddin Abdullah ◽  
Khairurrijal ◽  
Ferry Iskandar
Keyword(s):  
Heavy Oil ◽  
Average Particle Size ◽  
Viscosity Reduction ◽  
Experimental Result ◽  
Average Particle ◽  
X Ray ◽  
Microwave Assisted ◽  
Activity Test ◽  
Catalytic Activity Test ◽  
Scanning Electron

NixFe3-xO4 nanoparticles have been synthesized using microwave-assisted coprecipitation. Samples were prepared by using FeCl3•6H2O, FeSO4•7H2O, NiCl2•6H2O, and NH4OH as precursors. Concentrated black precipitates were produced after samples were heated in microwave 500 W 2.45 GHz for 3 minutes. According to X-Ray diffractogram, it was indicated that the NixFe3-xO4 was obtained. According to Scanning Electron Microscope (SEM) characterization, it was shown that Ni0.3Fe2.7O4 nanoparticles have spherical morphology and average particle size about 43 nm. In this research, NixFe3-xO4 nanoparticles were applied as catalyst in the reduction of heavy oil via aquathermolysis. In catalytic activity test, Fe3O4 and Ni0.3Fe2.7O4 nanoparticles were added respectively to the mixture of water and heavy oil in autoclave on temperature 120°C for 6 hours. Experimental result showed that the viscosity of heavy oil reduced 30% and 17% when Fe3O4 and Ni0.3Fe2.7O4 powders were added in aquathermolysis reaction, respectively.

One-pot microwave assisted approach for synthesis of CdSe/CdS core-shell quantum dots (QDs) and investigating optical properties

2016 ◽  
Vol 30 (07) ◽  
pp. 1650074 ◽  
Author(s):  
M. Molaei ◽  
F. Salari Bardsiri ◽  
A. R. Bahador ◽  
M. Karimipour
Keyword(s):  
Core Shell ◽  
Heat Sensitivity ◽  
X Ray Diffraction ◽  
Cdse Qds ◽  
One Pot ◽  
X Ray ◽  
Microwave Assisted ◽  
Transmission Electron ◽  
Core Shell Structure ◽  
Microwave Assisted Method

In this work, CdSe QDs were synthesized using a microwave assisted method and chemical reaction between NaHSe, CdSO4 at the presence of TGA as capping molecule. Thereafter without CdSe extraction, CdS shell was grown subsequently around CdSe cores by a reaction based on the heat sensitivity of Na2S2O3 dissociation. Synthesized QDs were characterized by means of X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), UV–Vis and photoluminescence (PL) spectroscopy. All of these analyzes confirmed formation of CdSe QDs and successfully growth of CdS shell on surface of CdSe to forming CdSe/CdS core-shell structure.

DIELECTRIC PROPERTIES OF ULTRAFINE Zn-DOPED CaCu3Ti4O12 CERAMIC

2012 ◽  
Vol 02 (01) ◽  
pp. 1250007 ◽  
Author(s):  
LAXMAN SINGH ◽  
U. S. RAI ◽  
K. D. MANDAL ◽  
MADHU YASHPAL
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Single Phase ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sintered Powder

Ultrafine powder of CaCu2.80Zn0.20Ti4O12 ceramic was prepared using a novel semi-wet method. DTA/TG analysis of dry powder gives pre-information about formation of final product around 800°C. The formation of single phase was confirmed by X-ray diffraction analysis. The average particle size of sintered powder of the ceramic obtained from XRD and Transmission electron microscopy was found 59 nm and 102 nm, respectively. Energy Dispersive X-ray studies confirm the stoichiometry of the synthesized ceramic. Dielectric constant of the ceramic was found to be 2617 at room temperature at 1 kHz.

Microwave Assisted Green Synthesis of Silver Nanoparticles Using Mulberry Leaves Extract and Silver Nitrate Solution

2018 ◽  
Author(s):  
Liem Le ◽  
The Nguyen ◽  
Dieu Nguyen
Keyword(s):  
Silver Nanoparticles ◽  
Silver Nitrate ◽  
Nitrate Solution ◽  
Average Particle Size ◽  
Silver Nitrate Solution ◽  
Spherical Particles ◽  
Average Particle ◽  
Mulberry Leaves ◽  
Microwave Assisted ◽  
Microwave Assisted Method

In this work, silver nanoparticles (AgNPs) were synthesized rapidly and eco-friendlily using the extract of Mulberry leaves and aqueous solution of silver nitrate without any toxic chemical [1,2]. The Mulberry leaves extract acts as both reducing agent and stabilizing agent. The UV-Vis spectrum shows peak at 430 nm. The TEM image of synthesized AgNPs sample shows spherical shaped particles whose size range from 15 to 20 nm. TEM image of nano silver solution sample synthesized by microwave assisted method shows nearly spherical particles with an average particle size of 10 nm. The absorption UV-vis spectrum of silver nanoparticles synthesized by microwave assisted method (AgNPsmw) shows a sharp absorption band around 415 nm. After two month storage of AgNPsmw, the absorption spectrum of AgNPsmw was taken again. The UV-Vis spectrum shows negligible peak changes of silver nanoparticles have occurred after two months of storage. The synthesized AgNPs material could be used as an antimicrobial, used in the field of textile and in wastewater treatment.

Studies on conducting nanocomposite with gallium nitride–doped ferrite, part-II

2017 ◽  
Vol 231 (1) ◽  
pp. 53-63
Author(s):  
Rajani Indrakanti ◽  
V Brahmaji Rao ◽  
C Udaya Kiran
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gallium Nitride ◽  
Crystallite Size ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

This article (a sequel to part-I that appeared earlier in the same journal) presents synthesis and characterisation details of conducting PPY-nanocomposite obtained from gallium nitride–doped ferrite and polypyrrole. The GaN-doped ferrite is synthesised by sol–gel method. GaNFe2O3f-PPY composites are prepared by impregnation technique. Using the SciFinder software we could not trace any report in the literature for this synthesised Ga(2x + 2)NFe2(49 − x)O3-PPY nanocomposites. The doped nanoferrite is combined with polypyrrole, an intrinsic conducting polymer, in three proportions by percentage (70%:30%), (90%:10%) and (97%:3%), to obtain two series each of three compositions for the conducting PPY-nanocomposite. The synthesised polymer composites are characterised by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, energy dispersive X-ray analysis and Fourier transform infrared spectroscopy. From our studies, it has been observed that the crystallite size of nanocomposites is decreased when compared to crystallite size of GaNFe2O3. The average particle size from histogram is in good agreement with Debye–Scherrer formula calculations. The scanning electron microscopy and transmission electron microscopy micrograms reveal that the particles are varying with the values of X and the percentage of PPY. The shapes observed are Globules,Tetrahedron,Nanorods of short and long lengths. The GaNFe2O3-PPY composites’ spectra revealed the shift in the band in comparison with the PPY spectra. Also, the wavelength is decreased, and vibrational frequency is increased.

The Impregnating Reduction Method for Synthesis of Pt–Ru Nanoparticles and Its Catalytic Performance for Methanol Electro-oxidation

2015 ◽  
Vol 12 (4) ◽  
Author(s):  
Long-long Wang ◽  
Hong-min Mao ◽  
Xiao-jin Zhou ◽  
Qun-jie Xu ◽  
Qiao-xia Li
Keyword(s):  
Reduction Method ◽  
Average Particle Size ◽  
Catalytic Performance ◽  
Average Particle ◽  
X Ray ◽  
Onset Potential ◽  
Ru Nanoparticles ◽  
Oxidation Of Methanol ◽  
Transmission Electron ◽  
Electro Oxidation

Well-dispersed and low Pt content Pt–Ru/C nanoparticles were prepared by a developed impregnating reduction method with sodium citrate as stabilizer. The as-prepared Pt–Ru/C catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and energy dispersive X-ray (EDX) analysis. TEM showed that the Pt–Ru particles were quite uniformly distributed on the surface of the carbon with an average particle size of 3.5–4.5 nm. The effect of pH values on methanol electro-oxidation reaction was examined by cyclic voltammetry (CV) and chronoamperometry (CA). Pre-adsorbed CO monolayer stripping was used to evaluate the antipoisoning ability. The results showed that Pt–Ru/C (pH = 8) catalyst had the highest catalytic activity and stability toward the oxidation of methanol. Finally, comparing Pt–Ru/C (Pt–Ru 20 wt.%, Pt/Ru = 1:1) catalysts with Pt/C (Pt 20 wt.%), the onset potential was 200 mV lower and electrochemical active area was much bigger.

Investigation on Carbonizing Behaviors of Nanometer-sized Cr2O3 Particles Dispersed on Alumina Particles by Metalorganic Chemical Vapor Deposition in Fluidized Bed

2005 ◽  
Vol 20 (8) ◽  
pp. 2154-2160 ◽  
Author(s):  
Hao-Tung Lin ◽  
Jow-Lay Huang ◽  
Wen-Tse Lo ◽  
Wen-Cheng J. Wei
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Graphite Furnace ◽  
Average Particle Size ◽  
Chemical Vapor ◽  
Average Particle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Alumina Particles

Nanoscaled Cr2O3 powder with an average particle size of 20–40 nm, coated on alumina particles, has been produced by means of chemical vapor deposition (CVD) in a fluidized chamber, using the pyrolysis of Cr(CO)6 precursor. Amorphous and crystalline Cr2O3 particles were obtained when the temperatures of the pyrolysis were 300 and 400 °C, respectively. To prepare nanoscaled Cr3C2 powder from the nanometer-sized Cr2O3, carbonizing behavior of the Cr2O3 particles was investigated. It was found that, when amorphous Cr2O3 powders were carbonized in graphite furnace at 1150 °C for 2 h in vacuum (10−3 Torr), the powder was transformed into Cr3C2, while the crystalline Cr2O3 was transformed into a mixture of Cr7C3 and Cr3C2. The examinations by x-ray diffraction, transmission electron microscopy, and energy dispersive spectroscopy confirmed the transformation of the nano-sized Cr3C2 powders. The results of thermogravimetry and differential thermal analysis indicated that the transformation temperature was ∼1089 °C for amorphous Cr2O3 and ∼1128 °C for crystalline Cr2O3.

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