• Journal of the Korean Ceramic Society
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• v.32 no.1
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• pp.45-50
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• 1995

In order to densify LAS(Lithuim Aluminosilicate)system compounds, we used metal alkoxides as precursors. Also Mg was added by sol-gel method using metal alkoxides to the LAS system for improving the sinterability, thermal and mechanical properties. The result was that the synthesizing temperature was lowered about 10$0^{\circ}C$, the sintering temperature was lowered by over 10$0^{\circ}C$ and MOR of samples from metal alkoxides was two times larger than that of sample form oxide.

• Journal of the Korean Ceramic Society
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• v.30 no.12
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• pp.987-992
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• 1993

In order to synthesize the heat resistance ceramics of LAS system, we studied on preparing the fine powder with homogeneity by sol-gel method using metal alkoxide. Various results were obtained depending on the composition and process. When the amount of H2O added at initial stage is higher than 10mol/$\ell$, and when the amount of catalyst is 0.1mol/$\ell$, the particle size of synthesized hydrate becomes finer. On condition that partial prehydrolysis time of TEOS is more than 50 hours, the monosized fine powder is obtained(below 1${\mu}{\textrm}{m}$).

• Journal of the Korean Ceramic Society
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• v.32 no.11
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• pp.1233-1240
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• 1995

LAS system, which is difficult to be sintered, was densified by using the powder synthesized from metal alkoxides. Sinterability, thermal and mechanical properties were improved through synthesizing the complex oxide powder from the addition of Ge as an alkoxide. As a result, the synthesizing and sintering temperature of the LAS system lowered by about 10$0^{\circ}C$ and its modulus of rupture (MOR) increased twice higher compared to the sample from the oxide by the direct method.

• Journal of the Korean Ceramic Society
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• v.31 no.5
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• pp.499-504
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• 1994

PbTiO3 thin films were prepared by sol-gel spin coating method using metal alkoxide and diethanolamine (DEA). The precipitation of the PbTiO3 sol occurred at pH 7.3 with HNO3 addition, regardless of the amount of DEA. The gelation time of the PbTiO3 sol was reduced with increasing amount of HNO3 and/or water. When the PbTiO3 films prepared by 0.2 molar coating solution were annealed at $650^{\circ}C$ for 30 min, dense and single phase perovskite films were obtained. Dielectric constant and loss tangent of the film were 239 and 0.01 at 1 kHz, respectively.

• 한국전기화학회:학술대회논문집
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• 1998.10a
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• pp.35-35
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• 1998

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.714-718
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• 2003

Usually for the commercial preparation of barium titanate films or ceramics the reaction atmosphere must be preferably in air. However, normally air is not used because it contains carbon dioxide, which can easily react with barium to form the undesired product barium carbonate, leading to unwanted second-phase formation in the (mal stages of the process. In the present work a series of perovskite barium titanate films was prepared by the sol-gel method, using a metal alkoxide solutions in the electrophoretic deposition (EPD). The influence of several process parameters, like sintering temperature of sol preparation before EPD and heat-treatment temperature and non-oxidized atmosphere, on the film properties is described.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.9-16
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• 2000

A survey over the role of sol-gel processing and metal alkoxides in the thin film preparation is given. The basic chemistry of the sol-gel process is complex due to the different reactivities of the network forming and the wide variety of reaction parameters. Despite the important progress in the investigations of the mechanisms of thin film formation, a direct relation of reaction parameters to functional oxide properties is still very difficult.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.814-819
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• 2000

The progress in the field of electronic materials has been especially significant for applications involving a range of electrical properties. Its importance is increasing with the increasing demand for integrated circuits. The sol-gel technique has been used for many years, and the metal alkoxides have featured prominently as source materials. The method consist of making a homogeneous solution of the component metal alkoxides in a suitable solvent, usually the parent alcohol; and then causing the hydrolysis under controlled conditions to produce a gel containing the hydrated metal oxide. The gel is then dried, and fired to produce a ceramic or glassy material at a temperature much lower than that required by the conventional melting process. This project consists of important theoretical considerations, processing techniques and applications related to electrophoresis derived thin films. In the electrophoretic process a metal alkoxide solution is gelled through hydrolysis-polymerization and converted the gel thin layer to an oxide by heating at relatively low temperatures.

• The Korean Journal of Ceramics
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• v.1 no.3
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• pp.137-142
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• 1995

Monodispersed $Al_2O_3-TiO_2$ Powder was prepared by metal-alkoxide hydrolsis. A homogeneous nucleation/growth occurred in the solutions containing ethanol, butanol and acetonitrile, and resulted in spherical, submicrometer-sized powder. The titania and the alumina crystals were formed at $800^{\circ}C$ and $1000^{\circ}C$, respectively. These crystala were subsequently reacted each other beyond $1320^{\circ}C$ and formed $Al_2TiO_5$. The relative densities of sintered bodies prepared with as-received powder were examined at the temperature range of 1300-$1500^{\circ}C$ and they were about 79% at $1300^{\circ}C$. The formation of aluminum titanata decreased the relative density at the temperature range of 1300-$1450^{\circ}C$, and at above $1450^{\circ}C$, the relative density started to increase again. It was observed that $\alpha-Al_2O_3$-doped aluminum titanate was more stable than pure aluminum titante at $1200^{\circ}C$.

• Analytical Science and Technology
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• v.26 no.3
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• pp.205-210
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• 2013

For the synthesis of crystalline LAS glass by sol-gel method, the effect of operation conditions including metal alkoxide ratio, nucleating agent composition and heat treatment on the crystalline properties was experimentally investigated. The gelation time and crystallization temperature were proportionally affected by the mole ratio of TEOS in metal alkoxides solution. The addition of $TiO_2$ had an influence on the increasing of the gelation time, but the crystallization temperature was rarely dependent on the adding of nucleating agent. The crystallinity of LAS glass was improved by the nucleating agent under same heat treatment conditions.