Ba2YCu3O6.9 Powder Preparation by Sol-Gel Emulsion Techniques

1987 ◽  
Vol 99 ◽  
Author(s):  
M. J. Cima ◽  
R. Chiu ◽  
W. E. Rhine
Keyword(s):  
Sol Gel ◽  
Nitrate Solution ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Powder Preparation ◽  
Powder Morphology ◽  
Aqueous Nitrate Solution ◽  
Emulsion Process ◽  
Micrometer Scale ◽  
Barium Yttrium

ABSTRACTBarium yttrium cuprate powders were prepared by a sol-gel emulsion process in which an aqueous nitrate solution containing Ba, Y, and Cu in the correct stoichiometry was emulsified in heptane. The resulting micrometer-sized droplets were gelled by adding a high-molecular-weight primary amine that extracts nitric acid from the aqueous phase and raises the pH of the droplets. Thermal gravimetric analysis revealed that the correct overall stoichiometry was obtained at temperatures lower than 400 °C during calcination, but X-ray diffraction showed that calcination at temperatures greater than 800° may be required to produce the correct phase. One possible advantage of this technique is the control of powder morphology on a micrometer scale so that powders can be prepared for advanced ceramics processing methods. Also, segregation of components, if any, will be restricted to distances less than one micrometer.

scholarly journals Irradiation of a Nanocomposite of Pseudoboehmite-Nylon 6,12

2010 ◽  
Vol 71 ◽  
pp. 28-33 ◽  
Author(s):  
Antônio Hortêncio Munhoz Jr. ◽  
Renato Meneghetti Peres ◽  
L.H. Silveira ◽  
Leonardo Gondim Andrade e Silva ◽  
L.F. de Miranda
Keyword(s):  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
Mechanical Tests ◽  
Polymeric Matrix ◽  
Nano Particles ◽  
Gravimetric Analysis ◽  
Polymeric Nanocomposites ◽  
X Ray Diffraction ◽  
Inorganic Substances ◽  
Sol Gel Process

Nanocomposites are nanometrical material particles embedded in a specific matrix. The degree of organization of the nanostructures and their properties depend on the nature of the organic and inorganic components of the structure that can generate synergic interactions. Polymeric nanocomposites are related to a class of hybrid materials where inorganic substances of nanometric dimensions are dispersed in a polymeric matrix. In the present work, nanocomposites of nylon 6,12 with different concentrations of pseudoboehmite obtained by sol-gel process were prepared with and without the presence of octadecylamine. After preparation, the samples were irradiated with a 200 kGy radiation dose in an electron accelerator. The pseudoboehmite nano particles were characterized by X-ray diffraction, scanning electron microscopy, differential thermal analysis and thermo gravimetric analysis. The nanocomposites were characterized by thermal and mechanical tests. The addition of pseudoboehmite promoted a reduction of the melting flow during the production of the composites evidencing the interaction of pseudoboehmite with the polymeric matrix, probably modifying its crystalline structure.

Structural, Thermal and Optical Properties of PVP Capped ZnO Films

2013 ◽  
Vol 678 ◽  
pp. 253-257 ◽  
Author(s):  
Thangaraj Pandiyarajan ◽  
B. Karthikeyan
Keyword(s):  
Optical Properties ◽  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
Emission Spectra ◽  
Hexagonal Wurtzite Structure ◽  
Zno Films ◽  
Band Edge Emission ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Absorption Measurements

In the present work we report, synthesis, structural, thermal and optical properties of ZnO incorporated PVP films. To prepare Polyvinylpyrolidone (PVP) capped ZnO films, simple room temperature sol gel method was adopted. Prepared PVP capped ZnO films were annealed at 800 C for 15 min and 30 min. X ray diffraction pattern shows prepared particles are in hexagonal wurtzite structure. Optical absorption measurements show an exciton absorption peak around ~ 370 nm. Emission spectra shows strong peaks around 329 and 333 nm are attributed to the band edge emission and broad peak found at 432 nm is attributed to the defect related emission. Thermal properties of the prepared films were studied by thermo gravimetric analysis. Interaction between the ZnO nanoparticles and PVP were investigated by Fourier Transform Infrared Spectroscopy (FTIR), it shows band at 441 cm-1 is attributed to Zn-O bond.

Doping of Palladium in Silica Nanofibers via Electrospinning and Sol-Gel Synthesize as Hydrogen Storage Material

2011 ◽  
Vol 471-472 ◽  
pp. 1040-1045 ◽  
Author(s):  
Samaneh Shahgaldi ◽  
Zahira Yaakob ◽  
Dariush Jafar Khadem ◽  
Wan Ramli Wan Daud ◽  
Edy Herianto Majlan
Keyword(s):  
Hydrogen Storage ◽  
Surface Area ◽  
High Surface ◽  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
High Surface Area ◽  
Chemical Vapour ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Silica Nanofibers

In recent years, one dimensional nanostructure, nanowires, nanofibers with unique properties have been a subject of intense research due to reduction of devise dimension, potential properties from the re-arrangement at the molecular level and high surface area. There are many methods for synthesize such as laser ablation, chemical vapour deposition, solution method micro pulling down method but all these method faced to the major disadvantages of being complicated with long wasting time and relatively high expense . The electrospinning recently used for producing ceramic, metal, and carbon nanofibers. In this report, we incorporate palladium into silica nanofibers for the first time, and the effect of doping of palladium into the silica nanofibers is investigated. The different ratio of palladium to silica and comparing with silica nanofibers is also reported. The composition, morphology, structure and surface area of silica, and silica palladium nanofibers were investigated by thermo gravimetric analysis (TGA), x-ray diffraction (XRD), scanning electron microscopy (SEM),Fourier transform infrared spectroscopy (FT-IR), and Micromeriics. To the best of our knowledge, investigation on characteristic on Silica palladium nanofibers has not been reported up to now. The result reveal that the silica nanofibers compare to silica doped with palladium have lower diameter, and also by increasing the temperature above 600 °C, the reduction in length of nanofibers happened. High surface area of silica palladium nanofibers can be one of the promising materials for hydrogen storage.

scholarly journals Co-Doped LaMnO3 Perovskite Structure Nanoparticles as a Bifunctional Electrocatalysts for Oxygen Reduction/Evolution Reactions

2020 ◽  
Vol 9 (7) ◽  
pp. 1060-1064
Keyword(s):  
Transition Metal Oxides ◽  
Perovskite Structure ◽  
Single Phase ◽  
Sol Gel ◽  
Perovskite Oxide ◽  
X Ray Diffraction ◽  
Powder Morphology ◽  
Bifunctional Electrocatalysts ◽  
Sol Gel Process ◽  
Perovskite Nanoparticles

Current paper, we have examined lanthanum manganese cobalt (LaMn1-xCoxO3 ) perovskite nanoparticles synthesized by utilizing the sol-gel process and following calcinated at 450 °C for 1h and 900 °C for 7h, respectively. The fabricated alloys show single-phase perovskite structure is an order of LaMn1-xCoxO3 (x = 0, 0.2, 0.4, 0.6, 0.8, 1). The synthesized LaMn1-xCoxO3 perovskite oxide nanoparticles have the crystal structure, and powder morphology properties were investigated by X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM), respectively. The perovskite structure has been shown to be particularly effective for the catalytic reactions of ORR and OER in alkaline medium. The merged valance transition metal oxides are bifunctional electrocatalysts which give rise to potential candidates, the electrochemical functioning of the LaMn1-xCoxO3 catalyst was entirely investigated. All compounds of ORR polarization curves show that the four-electron pathway, which results in KouteckyLevich is compatible with these perovskite structures. Current work, we describe B-site extend adding of Co ratio into perovskite structure is an appropriate strategy to increase ORR and OER electrocatalytic performance for application in metal-air batteries

Study of Pseudoboehmite Synthesis by Sol-Gel Process

2006 ◽  
Vol 45 ◽  
pp. 260-265 ◽  
Author(s):  
Antônio Hortêncio Munhoz Jr. ◽  
Leila Figueiredo de Miranda ◽  
G.N. Uehara
Keyword(s):  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
Ammonium Hydroxide ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Sol Gel Process ◽  
Different Temperatures ◽  
Sol Gel Synthesis

A pseudoboehmite was obtained by sol-gel synthesis using aluminum nitrate as precursor. It was used a 2n full factorial design for studying the effect of the temperature of synthesis, the concentration of ammonium hydroxide, and the radiation dose in the product of sol-gel synthesis. The product of the synthesis was analyzed by scanning electron microscopy, x-ray diffraction of the product (after firing the pseudoboehmite at different temperatures), and it was also analyzed the temperature of endothermic and exothermic transformations using the thermo gravimetric analysis (TG) and differential scanning calorimetry (DSC). The X-ray diffraction data show that α-alumina was obtained at 1100o C.

Sol-Gel Synthesis of the Strontium-Copper Oxycarbonate Superconductor Sr2CuO2(CO3)1−x(BO3)x

1996 ◽  
Vol 453 ◽  
Author(s):  
Audrey J. Babcock ◽  
Alexander R. Pico ◽  
Catherine J. Page
Keyword(s):  
Ambient Pressure ◽  
Sol Gel ◽  
Subsequent Treatment ◽  
Nominal Composition ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gel Preparation ◽  
Starting Solutions ◽  
Sol Gel Synthesis

AbstractWe have developed an ambient-pressure sol-gel synthetic route to superconducting borate-doped Sr2CuO2(CO3) using polyether alkoxide precursors. In our sol-gel preparation, the starting solutions contain strontium and copper alkoxide complexes in 2-(2-methoxy-ethoxy)ethanol. Boron is incorporated into the solution by using an aqueous boric acid solution for hydrolysis. Dried gels were examined by x-ray diffraction and thermal gravimetric analysis. By experimenting with various firing sequences and atmospheres we have established a successful route for reproducibly preparing relatively pure Sr2CuO2CO3 and boron-doped phases. Final products were characterized by x-ray diffraction, elemental analysis and magnetic susceptibility. Samples of nominal composition Sr2CuO2(CO3)0.85(BO2)0.15 are superconducting with a Tc(onset) of ∼25K. Subsequent treatment at 1100°C and 3 GPa for one hour increased Tc(onset) to ∼35K.

Luminescence properties of R2MoO6:Eu3+ (R = Gd, Y, La) phosphors prepared by Pechini sol-gel process

2005 ◽  
Vol 20 (10) ◽  
pp. 2676-2681 ◽  
Author(s):  
Maolin Pang ◽  
Xiaoming Liu ◽  
Jun Lin
Keyword(s):  
Grain Size ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Luminescence Properties ◽  
X Ray Diffraction ◽  
Powder Morphology ◽  
X Ray ◽  
Average Grain Size ◽  
Sem Study ◽  
Sol Gel Process

R2MoO6:Eu3+ (R = Gd, Y, La) phosphors were prepared by the Pechini sol-gel process. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), reflectance spectra, photoluminescence (PL) spectra, and lifetimes were used to characterize the resulting phosphors. The results of XRD indicate that all of the R1.96Eu0.04MoO6 (R = Gd, Y, La) phosphors crystallized completely at 800 °C. Y1.96Eu0.04MoO6 and Gd1.96Eu0.04MoO6 are of isomorphous monoclinic (α) structure, while La1.96Eu0.04MoO6 preferentially adopts the tetragonal (γ) form. FE-SEM study reveals that the samples mainly consist of aggregated particles with an average grain size ranging from 100 to 250 nm. The luminescent properties of R2MoO6:Eu3+ (R = Gd, Y, La) phosphors are largely dependent on their structure, grain size, and powder morphology. The isomorphous Y2MoO6:Eu3+ and Gd2MoO6:Eu3+ phosphors show very similar luminescence properties, which differ greatly from that of the La2MoO6:Eu3+ phosphor.

Synthesis of Y0.2ZrXCe0.8−XO1.9 Electrolytes From the Sol-Gel Method for Intermediate Temperature URSOFC Application

2012 ◽  
Vol 9 (4) ◽  
Author(s):  
Guo-Bin Jung ◽  
Ting-Chu Jao ◽  
Chia-Chen Yeh ◽  
Ming-Hsien Huang ◽  
Wang-Shen Su
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Relative Density ◽  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
Intermediate Temperature ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Gel Method ◽  
Sol Gel Method ◽  
Co Precipitation

A series of Y0.2ZrxCe0.8−xO1.9 compounds (0 ≤ x ≤ 0.6) had been prepared by the modified sol-gel method and characterized by powder X-ray diffraction, thermo-gravimetric analysis, four-probe resistivity, and Vickers’s hardness studies. The gels from co-precipitation were treated with heated 1-octanol. All of the samples showed fluoride structure after calcined at 600 °C. Sintering the powders of Y0.2Ce0.8O1.9 and Y0.2Zr0.6Ce0.2O1.9 at 1300 °C gave the relative density of 95.8% and 99%, respectively. 99% relative density could be obtained for all samples after sintering at 1500 °C. This study showed a much more improved result than that of the previous reports. The hardness was 13.7 GPa for the Y0.2Zr0.6Ce0.2O1.9 pellet, which was twice greater than that for Y0.2Ce0.8O1.9 (7.1 GPa). Therefore, the mechanical properties could be improved by the addition of ZrO2 to Y0.2ZrxCe0.8−xO1.9. At 800 °C, the electrical conductivity of Y0.2Ce0.8O1.9 and Y0.2Zr0.6Ce0.2O1.9 were 3.3 × 10−2 S/cm and 5.5 × 10−3 S/cm, respectively. The conductivity was decreased by the addition of ZrO2 to Y0.2Ce0.8O1.9. It showed that the conductivity and hardness of Y0.2Zr0.2Ce0.6O1.9 were 1.2 × 10−2 S/cm and 9.6 GPa, respectively, at 800 °C and could be a better electrolyte candidate for “intermediate-temperature” unitized regenerative solid oxide fuel cells.

Anti-Oxidation Behavior of Alumina Coating on Carbon Fibre by Sol-Gel Method

2009 ◽  
Vol 79-82 ◽  
pp. 819-822 ◽  
Author(s):  
Yu Dong Zhang ◽  
Xun Jia Su ◽  
Gen Liang Hou ◽  
Feng Guo
Keyword(s):  
Carbon Fibre ◽  
Sol Gel ◽  
Alumina Coating ◽  
Gravimetric Analysis ◽  
Carbon Fibres ◽  
X Ray Diffraction ◽  
Alumina Coatings ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method

Alumina coating on carbon fibre were prepared by Sol-gel method, and characterized by thermal gravimetric analysis, X-ray diffraction and scanning electron microscopy. Affected factors such as coating times, oxidation temperature and time were investigated. The results show alumina coatings on carbon fibres are crack-free with a smooth surface, therefore would improve anti-oxidation of carbon fibre significantly. Thickness is one of the most important factors on anti-oxidation of alumina coating, and in this work, thicker coatings have better anti-oxidation quality.

Sol-Gel Processing of Advanced Dielectric Ceramics for Microwave Applications

1989 ◽  
Vol 155 ◽  
Author(s):  
M. Schnoeller ◽  
W. Wersing
Keyword(s):  
Sol Gel ◽  
Wet Milling ◽  
X Ray Diffraction ◽  
Powder Morphology ◽  
Drying Procedures ◽  
Microwave Components ◽  
Sol Gel Process ◽  
Dielectric Ceramics ◽  
Gel Processing

ABSTRACTHighly dielectric ceramics make it possible to markedly miniaturize passive microwave components. We have successfully synthesized ceramic powders of the most important microwave ceramic systems (ZrTiSn)O2, Ba(TiNiZnTa)O3 and Ba(MgTa)O3 by using the sol-gel process. Nonaqueous solutions of metal organics together with different inorganic metal salts were used as precursors. The gels derived from these solutions are homogeneous and transparent. Different drying procedures were investigated in order to optimize powder morphology. Thermoanalytic methods and high -temperature x-ray diffraction were used to study the decomposition of xerogels and the formation of crystal phases, respectively. The calcination process was found to be complete at temperatures well below 750 °C.For the production of barium-containing powders, wet milling must be avoided because this washes out barium and thus causes undesired phases to appear. A dry milling step of the xerogel solves this problem. The prepared (ZrTiSn)O2 and Ba(TiNiZnTa)O3 already equal or surpass the quality of conventionally prepared ceramics.

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