Preparation of BaTiO3 by Sol-Gel-Processing

1988 ◽  
Vol 121 ◽  
Author(s):  
G. G. Tomandl ◽  
H. Rösch ◽  
A. Stiegelschmitt
Keyword(s):  
Sintering Temperature ◽  
Sol Gel ◽  
Milling Process ◽  
Special Treatment ◽  
Green Density ◽  
Barium Acetate ◽  
Calcium And Magnesium ◽  
Titanium Ethoxide ◽  
Future Work ◽  
Gel Processing

ABSTRACTBarium acetate, titanium ethoxide, and the acetates of calcium and magnesium and zirconium-n-propoxide as additives, were dissolved in an acetic acid methanol mixture. By adding water, this sol was converted to a gel.Extended investigations of the calcination result in a crystalline barium tita-nate without other titanate phases, with a very small amount of carbonate and a negligible contents of free carbon. Aggregates could not be destroyed totally by the milling process. Therefore, the green density of the green bodies reaches only 60 to 65 %. Thus, a minimum sintering temperature of 1200° C was necessary to obtain a density of at least 95 %. In future work, a special treatment to destroy the aggregates must be developed to lower the sintering temperature.

The Degradation and BMP Release Dynamics of Silica-Based Xerogels Modified by Adding Calcium and Magnesium or Sintering Process

2012 ◽  
Vol 151 ◽  
pp. 378-382 ◽  
Author(s):  
Xiao Sheng Li ◽  
Wei Lin ◽  
Feng Lan Xing
Keyword(s):  
Electron Microscope ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Diameter ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Mesoporous Structure ◽  
Silica Xerogel ◽  
Calcium And Magnesium

A new mesoporous silica xerogel used as biodegradable material was synthesized by improved sol-gel methods. The xerogel’s degradation character and property of releasing character for bone morphological protein (BMP)were modified by adding calcium (Ca) and phosphor (P) elements into pure silica xerogel, and uesing sintering processes, as well as adding magnesium (Mg) into silica xerogel. The differential thermal and thermogravimetric analysis (DTA-TG), X-Ray diffraction analysis(XRD), Fourier infrared spectrum analysis (FITR), N2 adsorption-desorption analysis, Scanning electron microscope(SEM) and Transmitting electron microscope (TEM) observation were used to measure the thermal effects, crystalline state, pore diameter and specific surface area, surface morphology and inner structure of the xerogels. The xerogel’s degradability and BMP release were studied by simulated body fluid (SBF) immersion. The results indicated that the synthesized xerogels were mesoporous structure with pore diameter around 3 nm and the big specific surface area about 1000 m2/g.They were non crystall with hydroxyl and micro-molecular silica-oxygen groups. Xerogels dried at low sintering temperature degraded completely in 42 days in bursting manner and degraded in linear curves with sintering temperature increased as well as adding calcium and magnesium into xerogels. The BMP release behaviour from the Mg-xerogel dried naturally was in controlled manner.

Synthesis and characterization of BaMgAl10O17:Eu phosphors derived by sol–gel processing

2002 ◽  
Vol 126 (2) ◽  
pp. 161-165 ◽  
Author(s):  
Junying Zhang ◽  
Zhongtai Zhang ◽  
Zilong Tang ◽  
Zishan Zheng ◽  
Yuanhua Lin
Keyword(s):  
Sol Gel ◽  
Synthesis And Characterization ◽  
Gel Processing

KNN-BF Lead-Free Piezoelectric Ceramics Synthesized by Sol-Gel Method

2015 ◽  
Vol 740 ◽  
pp. 3-6
Author(s):  
Guo Yuan Cheng ◽  
Xing Hua Fu ◽  
Xin Jin ◽  
Wen Hong Tao ◽  
Yu Qin Qiang
Keyword(s):  
Comparative Analysis ◽  
Citric Acid ◽  
Dielectric Loss ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Piezoelectric Ceramics ◽  
Lead Free ◽  
Gel Method ◽  
Sol Gel Method ◽  
Metal Chelator

KNN-BF piezoelectric ceramics synthesized by sol-gel method in this experiment. By controlling bismuth and iron content in the system to study effects of them. We selected citric acid as metal chelator and ethylene glycol as esterification agent. PH maintained 5-6 during preparation of the sol. Sintering temperature of ceramic selected 1100°C. Preparation ceramics under these conditions and comparative analysis, the structure of ceramics is single perovskite and shap of crystals are square block. With the increase of x, properties of ceramics firstly increases and then decreases: d33, εr, Qm, Kpreaching the maximum, values of them were 136pC/N, 630(f =1KHz), 212, 0.41 respectively; dielectric loss to minimum is 0.07(f =1KHz); at this point, ceramics had best performance.

Chemical Solution Deposition of Lanthanum Zirconate Buffer Layers on Biaxially Textured Ni–1.7% Fe–3% W Alloy Substrates for Coated-conductor Fabrication

2002 ◽  
Vol 17 (6) ◽  
pp. 1543-1549 ◽  
Author(s):  
S. Sathyamurthy ◽  
M. Paranthaman ◽  
T. Aytug ◽  
B. W. Kang ◽  
P. M. Martin ◽  
...  
Keyword(s):  
Sol Gel ◽  
Rf Sputtering ◽  
Cube Texture ◽  
Dip Coating ◽  
Buffer Layers ◽  
Lanthanum Zirconate ◽  
Solution Deposition ◽  
Ybco Films ◽  
Current Densities ◽  
Gel Processing

Sol-gel processing of La2Zr2O7 (LZO) buffer layers on biaxially textured Ni–1.7% Fe–3% W alloy substrates using a continuous reel-to-reel dip-coating unit has been studied. The epitaxial LZO films obtained have a strong cube texture and uniform microstructure. The effects of increasing the annealing speed on the texture, microstructure, and carbon content retained in the film were studied. On top of the LZO films, epitaxial layers of yttria-stabilized zirconia and Ceria (CeO2) were deposited using rf sputtering, and YBa2Cu3Ox (YBCO) films were then deposited using pulsed laser deposition. Critical current densities (Jc) of 1.9 MA/cm2 at 77 K and self-field and 0.34 MA/cm2at 77 K and 0.5 T have been obtained on these films. These values are comparable to those obtained on YBCO films deposited on all-vacuum deposited buffer layers and the highest ever obtained using solution seed layers.

Effect of acetylacetone on the preparation of PZT materials in sol–gel processing

2002 ◽  
Vol 96 (3) ◽  
pp. 307-312 ◽  
Author(s):  
Luqian Weng ◽  
Xujin Bao ◽  
Kwesi Sagoe-Crentsil
Keyword(s):  
Sol Gel ◽  
Gel Processing

Diamond Machinable Sol-Gel Silica Based Hybrid Coatings for High Precision Optical Molds

2010 ◽  
Vol 438 ◽  
pp. 65-72 ◽  
Author(s):  
Andreas Mehner ◽  
Ju An Dong ◽  
Timo Hoja ◽  
Torsten Prenzel ◽  
Yildirim Mutlugünes ◽  
...  
Keyword(s):  
Injection Molding ◽  
High Precision ◽  
Sol Gel ◽  
Processing Parameters ◽  
Hybrid Coatings ◽  
Optical Elements ◽  
Optical Components ◽  
New Approach ◽  
Free Silica ◽  
Gel Processing

The demand for high precision optical elements as micro lens arrays for displays increases continually. Economic mass production of such optical elements is done by replication with high precision optical molds. A new approach for manufacturing such molds was realized by diamond machinable and wear resistant sol-gel coatings. Crack free silica based hybrid coatings from base catalyzed sols from tetraethylorthosilicate (TEOS: Si(OC2H5)4) and methyltriethoxysilane (MTES: Si(CH3)(OC2H5)3) precursors were deposited onto pre-machined steel molds by spin coating process followed by a heat treatment at temperatures up to 800°C. Crack-free multilayer coatings with a total thickness of up to 18 µm were achieved. Micro-machining of these coatings was accomplished by high precision fly cutting with diamond tools. Molds with micro-structured coatings were successfully tested for injection molding of PMMA optical components. The wear resistance of the coatings was successfully tested by injection molding of 1000 PMMA lenses. Hardness and elastic modulus of the coatings were measured by nano indentation. The chemical composition was measured by X-ray photo electron spectroscopy (XPS) as a function of the sol-gel processing parameters.

scholarly journals Metallkomplexe in Anorganischen Matrices, 5 [1] / Metal Complexes in Inorganic Matrices, 5 [1]

1991 ◽  
Vol 46 (6) ◽  
pp. 783-788 ◽  
Author(s):  
Christian Egger ◽  
Ulrich Schubert
Keyword(s):  
Acetic Acid ◽  
Metal Complexes ◽  
Phenylacetic Acid ◽  
Sol Gel ◽  
Rhodium Complex ◽  
Gel Processing ◽  
Inorganic Matrices

A heterogenized rhodium complex, prepared by sol-gel processing of Rh(CO)Cl[PPh2CH2CH2Si(OEt)3]2 and Si(OEt)4, is shown to catalyze the conversion of the silanes H4-nSiPh„ (n = 1 - 3) or (HMe2Si)2O to (poly)siloxanes by air or water. Using THF as a solvent, the silanoles Ph3SiOH or Ph2Si(OH)2 are obtained instead. The reaction of phenylacetic acid or acetic acid with HSiPh3 to give silyl esters is catalyzed by the same compound.

Apatite-forming ability and mechanical properties of PTMO-modified CaO–SiO2 hybrids prepared by sol–gel processing: effect of CaO and PTMO contents

Biomaterials ◽  
2002 ◽  
Vol 23 (14) ◽  
pp. 3033-3040 ◽  
Author(s):  
Noboru Miyata ◽  
Ken-ichi Fuke ◽  
Qi Chen ◽  
Masakazu Kawashita ◽  
Tadashi Kokubo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Sol Gel ◽  
Processing Effect ◽  
Gel Processing
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