scholarly journals The Influence of the Compositions of Reactants on the Luminescence Intensity of Zn2SiO4: Mn Synthesized by Sol-Gel Method Using Hydrochloric Acid 

2021 ◽  
Vol 31 (1) ◽  
pp. 1-5
Keyword(s):  
Hydrochloric Acid ◽  
Luminescence Intensity ◽  
Ph Value ◽  
Phase 1 ◽  
Sol Gel ◽  
Molar Ratio ◽  
Rhombohedral Structure ◽  
Spherical Form ◽  
Gel Method ◽  
Sol Gel Method

The green emitting phosphor based on manganese activated zinc silicate was successfully synthesized by the sol – gel method using hydrochloric acid. The suitable molar ratio of the initial components is Zn(CH3COO)2: MnSO4: TEOS = 1.98: 0.02: 1 corresponding to the product formula Zn1.98Mn0,02SiO4. The suitable pH value for the gelation is 3, ratio of water phase: ethanol phase = 1:1 and the product when calcining the obtained gel at 10000C for 60 minutes has highest luminescence intensity. The synthesized phosphor consists of Zn2SiO4 with rhombohedral structure and emits a green light at the 525 nm wavelength when excited by the 325 nm UV radiation. The produced sample has spherical form with the particles size being 100 nm.

Synthesis of YIG Nanopowders by Sol-Gel Method

2008 ◽  
Vol 368-372 ◽  
pp. 582-584 ◽  
Author(s):  
Zhan Xing Sun ◽  
Ming Hao Fang ◽  
De Hua Chen ◽  
Li Xian Wei ◽  
Yan Gai Liu ◽  
...  
Keyword(s):  
Ph Value ◽  
Raw Materials ◽  
Thermal Analyses ◽  
Sol Gel ◽  
Molar Ratio ◽  
Gel Method ◽  
Sol Gel Method ◽  
Metal Nitrates ◽  
Average Grain Size ◽  
Iron Garnet

Yttrium iron garnet (YIG) nanopowders were synthesized by sol-gel method using Fe(NO3)3·9H2O, Y(NO3)3·6H2O as raw materials. The influence of heat treatment, the citric acid to metal nitrates molar ratio (CA / MN) and PH value on the synthesized powders were investigated using scanning electron microscopy (SEM), thermal analyses (DTA/TGA) and X-ray diffraction (XRD). YIG powders with average grain size of 80~90nm were synthesized after calcining at 1000°C for 4h.

Studies on the Composite Thermochomic Energy-Storage Materials Prepared by Sol-Gel Method

2011 ◽  
Vol 331 ◽  
pp. 83-88 ◽  
Author(s):  
Zhi Lei Wu ◽  
Xiao Guang Ma
Keyword(s):  
Energy Storage ◽  
Ph Value ◽  
Orthogonal Design ◽  
Sol Gel ◽  
Chromatic Aberration ◽  
Molar Ratio ◽  
Energy Storage Materials ◽  
Gel Method ◽  
Sol Gel Method ◽  
Storage Materials

Composite thermochromic energy-storage materials (CTEM)were prepared by sol-gel method, Factors exerting influence on thermochomic and thermal properties of composite materials were discussed, such as the molar ratio of ester to water, the dosage of thermochomic materials, pH value were optimized via 3 factors and 3 levels of L9 (33) orthogonal design. Based on the research，when the molar ratio of ester to water was 1:7, dosage of thermochomic materials was 14g, pH value was 3, the optimal chromatic aberration and cooling time of the composite thermochromic energy-storage materials was successfully acquired. Results showed that the thermochomic materials were firmly enwrapped in silica of three-dimensional network structure, solving the problem of liquid release in the process of phase change and increasing its applications in textile, meanwhile it also had excellent thermochomic and thermal performance.

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.

The Research on ODS Iron Powder by Sol-Gel Method

2012 ◽  
Vol 476-478 ◽  
pp. 1146-1149 ◽  
Author(s):  
Xiao Yu ◽  
Zhi Meng Guo ◽  
Jun Jie Hao ◽  
Wei Wei Yang
Keyword(s):  
Mechanical Alloying ◽  
Iron Powder ◽  
Ferritic Steel ◽  
Ph Value ◽  
Sol Gel ◽  
Oxide Dispersion Strengthened ◽  
Steel Powder ◽  
Raw Material ◽  
Gel Method ◽  
Sol Gel Method

Oxide dispersion strengthened (ODS) ferritic steel which contains Y2O3 dispersion is one of the most promising candidates for fast neutron reactor cladding materials due to its excellent swelling resistance to neutron and superior creep resistance in high temperature. There are many ways to prepare ODS ferritic steel and the most commonly used method is mechanical alloying. However, ODS ferritic steel produced by the method of mechanical alloying is poor in the plasticity and impact property. Moreover, the anisotropies of structure and properties are obvious in the follow-up processing. In this paper, in order to reduce the cost, iron powder is used as raw material instead of ferritic steel powder. The complexing sol-gel method is adopted to prepare ODS iron-powder. There are many advantages of the sol-gel method such as the small size of disperse phase and the high uniformity. Besides, it is easy to control the conditions of reaction such as the water content, the bath temperature and the PH value. The gel-coated iron powder can be prepared under the appropriate environmental conditions. Then, we can obtain iron powder with Y2O3 dispersion after heating and reducing the gel-coated iron powder. By the spark plasma sintering(SPS), the ODS iron powder can be densified and we can observe the microstructure and test the performance. The results reveal the Y2O3 dispersion of ODS iron-powder by sol-gel method is uniform and the mechanical property is excellent.

Iron-Zircon Pigments Prepared by Non-Hydrolytic Sol-Gel Method at Low Temperature

2011 ◽  
Vol 412 ◽  
pp. 223-226 ◽  
Author(s):  
Wei Hui Jiang ◽  
Yan Hui Yang ◽  
Qing Xia Zhu ◽  
Jian Min Liu
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Ferric Chloride ◽  
Lithium Fluoride ◽  
Sol Gel ◽  
Zircon Crystal ◽  
Molar Ratio ◽  
Gel Method ◽  
Sol Gel Method ◽  
Anhydrous Ferric Chloride

ron-zircon pigment has been synthesized by non-hydrolytic sol-gel method using zirconium chloride and tetraethoxysilane as precursors, anhydrous ferric chloride as colorant, lithium fluoride as mineralizer and anhydrous ethanol as solvent. Iron-zircon pigment has been characterized by means of DTA-TG, XRD, Colorimeter and TEM. The results show that only a small fraction of iron is incorporated in the zircon crystal structure while the remaining iron cations are trapped within the zircon matrix. The iron-zircon with the red value (a*) of 20.64 can be synthesized at 700°C with the optimum Fe/Zr molar ratio of 0.2.

Iron and Iron-oxide on Silica Nanocomposites Prepared by the Sol-gel Method

2002 ◽  
Vol 17 (3) ◽  
pp. 590-596 ◽  
Author(s):  
G. Ennas ◽  
M. F. Casula ◽  
G. Piccaluga ◽  
S. Solinas ◽  
M. P. Morales ◽  
...  
Keyword(s):  
Sol Gel ◽  
Silica Matrix ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Gel Method ◽  
Sol Gel Method ◽  
Silica Nanocomposites ◽  
Transmission Electron ◽  
Nanometric Particles

γ–Fe2O3/SiO2 and Fe/SiO2 nanocomposites, with a Fe/Si molar ratio of 0.25, were prepared by the sol-gel method starting from ethanolic solutions of tetraethoxysilane and iron (III) nitrate. After gelation the xerogels were oxidated or reduced. Samples were investigated by transmission electron microscopy, x-ray diffraction, differential scanning calorimetry, and thermogravimetry. Magnetic properties of the samples were investigated at room temperature (RT) and at 77 K. Nanometric particles supported in the silica matrix were obtained in all cases. Bigger particles (10 nm) were obtained in the case of Fe/SiO2 nanocomposites with respect to the γ–Fe2O3/SiO2 samples (5–8 nm). A slight effect of sol dilution on particle size was observed only in the case of γ–Fe2O3/SiO2 nanocomposites. A superparamagnetic behavior was shown at RT only by γ–Fe2O3/SiO2 nanocomposites. Iron-based composites exhibited coercivity values higher than 700 Oe at RT.

DIFFERENT MORPHOLOGIES OFTiO2NANOSTRUCTURES IN ACIDIC AND BASIC SOL–GEL METHOD

NANO ◽  
2010 ◽  
Vol 05 (05) ◽  
pp. 279-285 ◽  
Author(s):  
M. H. IMANIEH ◽  
Y. VAHIDSHAD ◽  
P. NOURPOUR ◽  
S. SHAKESI ◽  
K. SHABANI
Keyword(s):  
Ph Value ◽  
Sol Gel ◽  
Simple Method ◽  
Gel Method ◽  
Sol Gel Method ◽  
New Process ◽  
Nanocrystalline Titanium ◽  
Acidic Conditions ◽  
Nanocrystalline Titanium Dioxide ◽  
First Time

In this research, nanocrystalline titanium dioxide (TiO2) particles were prepared by a modified alkoxide technique under basic and acidic conditions at room temperatures. A simple method for preparing different morphology of TiO2has been developed. The reaction condition was used to control the crystalline size, phase and morphology of the TiO2nanostructures. In this process by adjusting the Rw(water to precursor ratio) and pH value the hydrolysis and condensation reactions were controlled. This led to the development of a new process to produce TiO2nanorod (for the first time by sol–gel method) at high pH value (basic) while the water content was sufficient whereas at low pH value (acidic) nanosphere TiO2were obtained. The powders were characterized by DTA, XRD, FE-SEM and UV–vis techniques and their physical properties were compared.

N-Doped Cu11O2 (VO4)6 Photocatalyst Prepared by Sol-Gel Method

2011 ◽  
Vol 393-395 ◽  
pp. 1287-1290
Author(s):  
Min Wang ◽  
Qiong Liu ◽  
Qi Xing
Keyword(s):  
Uv Light ◽  
Sol Gel ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Photodegradation Rate ◽  
Triclinic Phase ◽  
Synthesized Materials

The N-doped Cu11O2 (VO4)6 photocatalyst was prepared using the sol-gel method. Techniques of X-ray diffraction (XRD), scanning electron microscope (SEM) have been employed to characterize the as-synthesized materials. During liquid phase photocatalytic degradation of Methy lorange(MO) under the UV-light, the as-prepared N-doped Cu11O2 (VO4)6 exhibits higher activity than the pure Cu11O2 (VO4)6 without doped N. It found that the N-doped Cu11O2 (VO4)6 prepared with the molar ratio of citric acid to metal inons be 2:1, N/Cu molar ratio of 12%, pH=7 and calcinated under 500°C for 4 hours was pure triclinic phase. In this conditions, the sample had highest photocatalytic activity with the photodegradation rate was about 94.42% or so in 60min under 20W ultraviolet lamp.

Synthesis and Characterization of Fluorine-Doped Tin Oxide Nanocrystals Prepared by Sol-Gel Method

2014 ◽  
Vol 977 ◽  
pp. 59-62 ◽  
Author(s):  
Jun Qing Tian ◽  
Hai Ying Shi ◽  
Wei Zheng
Keyword(s):  
Tin Dioxide ◽  
Sol Gel ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Gel Method ◽  
Sol Gel Method ◽  
Hall Effect Sensor ◽  
Precursor Material ◽  
20 Nm

Fluorine-doped tin dioxide (FTO) nanocrystals were prepared with sol–gel method using SnCl4·5H2O and NH4F as precursor material. The FTO was characterized with X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Differential Thermal Analysis and Thermal Grativity (DTA-TG) and Infrared Radiation (IR) respectively. The electrical property was measured with Hall Effect Sensor. The result of XRD and SEM shows that FTO nanocrystal size is about 20 nm and the dimension of the grain is about 300 nm. IR spectrum analysis proves fluorine doping. The crystal phase transformation was discussed with DTA-TG curve. When the sintering temperature is 450°C, the sintering time is 60 min, and the molar ratio of F to Sn is 2:10, the sheet resistance of FTO film is 107Ω/□.

scholarly journals Effect of pH and annealing temperature on the structural and magnetic properties of cerium-substituted yttrium iron garnet powders produced by the sol-gel method

2016 ◽  
Vol 34 (2) ◽  
pp. 362-367 ◽  
Author(s):  
I. Yarici ◽  
M. Erol ◽  
E. Celik ◽  
Y. Ozturk
Keyword(s):  
Magnetic Properties ◽  
Yttrium Iron Garnet ◽  
Annealing Temperature ◽  
Ph Value ◽  
Sol Gel ◽  
Chelating Agent ◽  
Yttrium Iron ◽  
Gel Method ◽  
Sol Gel Method ◽  
Iron Garnet

AbstractCerium substituted yttrium iron garnet (Ce0.2Y2.8Fe5O12; Ce-YIG) nanoparticles were produced via the sol-gel method from solutions of Ce-, Y- and Fe-based precursors, a solvent and a chelating agent. The solutions were dried at 200°C and heat treated at temperatures between 800 °C and 1400°C for 3 h in air. The effects of pH and annealing temperature on the structure, phase formation, magnetic properties and crystallite size were investigated. A cubic YIG phase was obtained for the sample annealed at 1400 °C. The presented results showed that the pH value of the starting solution affects the crystal size and consequently, the saturation magnetization.

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