Preparation of Tungsten-Doped VO2 (M) Nanoparticles through Sol-Gel Method and Hydrothermal Synthesis

2014 ◽  
Vol 881-883 ◽  
pp. 960-963 ◽  
Author(s):  
Ji Qi ◽  
Bin Zhao ◽  
Naisen Yu ◽  
Chen Niu ◽  
Guan Gran Sun
Keyword(s):  
Phase Transition ◽  
Vanadium Dioxide ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
New Process ◽  
Scanning Electron

A new process was developed for synthesizing tungsten-doped vanadium dioxide VO2(M) from ammonium metavanadate. The process includes obtaining V2O5by pyrolysing NH4VO3, doping tungsten in V2O5by sol-gel method, and reducing V2O5to VO2(M) with hydrazine by hydrothermal method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) were applied to characterizing the product. The experimental results indicated that tungsten doped VO2(M) nanoparticles were successfully synthesized. The product VO2(M) presents mainly rod-like and block-like morphology. The phase transition temperature decreases with tungsten doped amount increasing, the phase transition takes place over the range from 36.23°C to 62.16°C and the largest enthalpy of the phase transition is 16.24J/g.

scholarly journals Nanomaterial Host Bands Effect on the Photoluminescence Properties of Ce-Doped YAG Nanophosphor Synthesized by Sol-Gel Method

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
L. Guerbous ◽  
A. Boukerika
Keyword(s):  
Energy Levels ◽  
Sol Gel ◽  
Yellow Emission ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Annealing Temperatures

Cerium trivalent (Ce3+) doped YAG nano-sized phosphors have been successfully synthesized by sol-gel method using different annealing temperatures. The samples have been characterized by X-ray diffraction (XRD), thermogravimetry (TG), differential scanning calorimetry (DSC) analysis, Fourier transform infrared (FTIR) spectroscopy, and steady photoluminescence (PL) spectroscopy. X-ray diffraction analysis indicates that the pure cubic phase YAG was formed and strongly depends on the cerium content and the annealing temperature. It was found that the grain size ranges from 30 to 58 nm depending on the calcination temperature. The YAG: Ce nanophosphors showed intense, green-yellow emission, corresponding to Ce3+5d1→2F5/2,2F7/2transitions and its photoluminescence excitation spectrum contains the two Ce3+4f1→5d1, 5d2bands. The crystal filed splitting energy levels positions 5d1and 5d2and the emission transitions blue shift with annealing temperatures have been discussed. It was found that the Ce3+4f1ground state position relative to valence band maximum of YAG host nanomaterial decreases with increasing the temperature.

Effects of La0.5Sr0.5CoO3 sol concentration on the microstructure and dielectric properties of Ba0.6Sr0.4TiO3 films prepared by sol-gel method on Ti substrate

2012 ◽  
Vol 1494 ◽  
pp. 253-258
Author(s):  
Dan Jiang ◽  
Songwei Han ◽  
Xuelian Zhao ◽  
Jinrong Cheng
Keyword(s):  
Electron Microscopy ◽  
Dielectric Properties ◽  
Sol Gel ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Bst Films ◽  
Scanning Electron

ABSTRACTBa0.6Sr0.4TiO3 (BST) thin films were deposited on La0.5Sr0.5CoO3 (LSCO) buffered Ti substrates. Both BST and LSCO were prepared by sol-gel method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis were used to investigate the effect of LSCO sol concentration on the crystallinity and surface morphology of the films. The results show that with the increase of LSCO sol concentration, BST films show variation of the structure and dielectric properties. BST films for LSCO of 0.2 mol/L exhibit a better crystallinity and improved dielectric properties, with the tunability, dielectric constant and tanδ of 30%, 420 and 0.028 respectively.

scholarly journals Nanocomposites Produced by Growth of Hydroxyapatite onto Silica Particles Prepared by the Sol-Gel Method

1996 ◽  
Vol 5 (1) ◽  
pp. 096369359600500 ◽  
Author(s):  
R. Rodríguez ◽  
J. Coreño ◽  
J.A. Arenas ◽  
V.M. Castaño
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sol Gel ◽  
Silica Particles ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Silica Sols ◽  
Scanning Electron

The growth of hydroxyapatite, a calcium phosphate, on silica particles prepared by the sol-gel method is reported. The size of the silica sols was controlled by changing the pH of water before the mixing with the alcoxide. Particle size profiles of sols were obtained by using dynamical light scattering. The characterisation of the composites, of nanometer sizes, was performed by employing X-ray diffraction, scanning electron microscopy and Raman spectroscopy.

Magnetite and Anti-Microbial Properties of Ag2O-CaO-Fe2O3-SiO2 Glass-Ceramic by Sol-Gel Method

2011 ◽  
Vol 399-401 ◽  
pp. 869-872
Author(s):  
Bin Li ◽  
Hai Feng Chen ◽  
Li Hua Wen ◽  
Chen Ma
Keyword(s):  
Glass Ceramic ◽  
Crystallization Process ◽  
Sol Gel ◽  
Frequency Factor ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Heat Treated

Ag2O-CaO-Fe2O3-SiO2glass-ceramic was prepared by the sol-gel method. Differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM) were used to investigate crystallization process of Ag2O-CaO-Fe2O3-SiO2glass. The kinetic results show that the values of the activation energy and frequency factor of the glass are 441.991 KJ/ mol and 1.58×1020, respectively. And the dimensionality of crystal growth, n, decreases as the heating rate increases. The crystalline phases of the glass-ceramic are magnetite, wollastonite and minor hematite. The saturation magnetization and coercive force of the heat-treated glass are 0.08 Wb/m2and 14 KA/m at room temperature. The glass-ceramic has some capacity of anti-microbial.

Effect of substrates on the growth and properties of LiNbO3 films by the sol-gel method

1994 ◽  
Vol 9 (4) ◽  
pp. 980-985 ◽  
Author(s):  
Nam H. Hur ◽  
Yong K. Park ◽  
Dong H. Won ◽  
Kwangsoo No
Keyword(s):  
Sol Gel ◽  
Epitaxial Films ◽  
Optical Measurements ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Sol Gel Process ◽  
Optimized Conditions ◽  
Scanning Electron

Thin films of LiNbO3 were fabricated on sapphire(012), MgO(OOl), and Si(111) substrates by the sol-gel process. Under optimized conditions, films deposited onto sapphire(012) were epitaxially grown. Preferred orientations, however, were not observed in the films on MgO(001) and Si(111) by x-ray diffraction measurements. Morphology of the epitaxial films on sapphire(012) was examined by scanning electron microscopy, which indicated that the films were smooth and had a pore-free surface. Electrical and optical measurements on the epitaxial films revealed that the properties of the films were very similar to those of the single crystalline LiNbO3, while films deposited onto Si(111) did not show any orientational behaviors. The highest quality films with epitaxy were obtained only on sapphire(012). The remaining substrates appeared to be not suitable for growing epitaxial LiNbO3 films by the sol-gel method.

Dielectric Properties of Zr-Doped CCTO Based Ceramics Prepared via Sol-Gel Method

2012 ◽  
Vol 528 ◽  
pp. 121-125 ◽  
Author(s):  
Chao Qun Ye ◽  
Li Ding
Keyword(s):  
Dielectric Properties ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Impedance Analyzer ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Microstructure Morphology ◽  
Comprehensive Characterization ◽  
Scanning Electron

The CaCu3Ti4O12 and Zr-doped polycrystalline CaCu3Zr0.05Ti3.95O12 were prepared via sol-gel method. Comprehensive characterization including X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) equipped with Energy-dispersive X-ray spectroscopy (EDX) were employed to characterize the microstructure, morphology and composition. The dielectric properties of the CCTO based ceramics were studied using impedance analyzer. The results show that replacement of Zr in the Ti- site can achieve the effect of regulation of the dielectric properties.

Impedance Spectroscopy Study of LiTaO3 Powder Synthesized via Sol-Gel Method

2012 ◽  
Vol 545 ◽  
pp. 275-278 ◽  
Author(s):  
Lili Widarti Zainuddin ◽  
Norlida Kamarulzaman
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Sol Gel ◽  
Rhombohedral Structure ◽  
Spectroscopy Study ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Impedance Spectroscopy Study

A ceramics sample of LiTaO3 was prepared using a sol-gel method. The sample is annealed at 750 °C for 48 hours. X-ray diffraction analysis indicate the formation of single phase, rhombohedral structure. An ac impedance study was used to analyse the conductivity of LiTaO3 at room temperature and at various temperatures.

Magnetic Properties of Bulk Zn0.95-XMnXFe0.05O2 Prepared by Sol-Gel Method and Subsequent Hot Pressing

2011 ◽  
Vol 268-270 ◽  
pp. 356-359 ◽  
Author(s):  
Wen Song Lin ◽  
C. H. Wen ◽  
Liang He
Keyword(s):  
Magnetic Properties ◽  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
Sol Gel ◽  
Secondary Phase ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Doped Zno

Mn, Fe doped ZnO powders (Zn0.95-xMnxFe0.05O2, x≤0.05) were synthesized by an ameliorated sol-gel method, using Zn(CH3COO)2, Mn(CH3COO)2and FeCl2as the raw materials, with the addition of vitamin C as a kind of chemical reducer. The resulting powder was subsequently compacted under pressure of 10 MPa at the temperature of 873K in vacuum. The crystal structure and magnetic properties of Zn0.95-xMnxFe0.05O2powder and bulk samples have been investigated by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). X-ray photoelectron spectroscopy (XPS) was used to study chemical valence of manganese, iron and zinc in the samples. The x-ray diffraction (XRD) results showed that Zn0.95-xMnxFe0.05O (x≤0.05) samples were single phase with the ZnO-like wurtzite structure. No secondary phase was found in the XRD spectrum. X-ray photoelectron spectroscopy (XPS) showed that Fe and Mn existed in Zn0.95-xMnxFe0.05O2samples in Fe2+and Mn2+states. The results of VSM experiment proved the room temperature ferromagnetic properties (RTFP) of Mn, Fe co-doped ZnO samples.

scholarly journals Effect of Preheating Temperature on Synthesis of Pure BiFeO3 via Sol–Gel Method

Nanopages ◽  
2019 ◽  
pp. 1-11
Author(s):  
G. M. Taha ◽  
M. N. Rashed ◽  
M. S. El-Sadek ◽  
M. A. Moghazy
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Pure Bifeo3 ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Transmission Electron ◽  
Preheating Temperature

Abstract BiFeO3 (BFO) nanopowder was synthesized in a pure form via a sol- gel method based on glycol gel reaction. Effect of drying and preheating temperature on preventing other phases was studied. Many parameters were studied as calcination temperature and time & stirring temperature as well. The prepared powder was characterized by X-Ray Diffraction of powder (XRD) and Transmission Electron Microscope (TEM). High pure BiFeO3 was obtained by preheated process at 400 °C for 0.5 h and calcination at 600 °C for 0.5 h without any impurities compared to dry at110 °C.

Effect of Synthesis Conditions on the Structure and Electrochemical Properties of LiNi1/2Mn1/2O2 by Sol Gel Method

2011 ◽  
Vol 399-401 ◽  
pp. 1447-1450
Author(s):  
Zhi Yong Yu ◽  
Han Xing Liu
Keyword(s):  
Electrochemical Properties ◽  
Sol Gel ◽  
Electrochemical Analysis ◽  
X Ray Diffraction ◽  
Capacity Fading ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Synthesis Conditions ◽  
A Current

The layered LiNi1/2Mn1/2O2 cathode materials were synthesized by a sol gel method. The effects of calcination temperature and time on the structural and electrochemical properties of the LiNi1/2Mn1/2O2 were investigated. The prepared samples were characterized by X-ray diffraction (XRD) and electrochemical analysis. The results revealed that the layered LiNi1/2Mn1/2O2 material could be optimal synthesized at temperature of 900°C for 10h. The sample prepared under the above conditions has the highest initial discharge capacity of 151 mAh/g and showed no dramatic capacity fading during 20 cycles between 2.5-4.5V at a current rate of 20mA/g.

Sign in / Sign up

Export Citation Format

Share Document