• 한국세라믹학회지
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• 제43권10호
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• pp.635-639
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• 2006

Dispersion behavior of the slurries consisted of Pb or Bi-based glass frits, which are used for the fabrication of green sheet as PDP front panel transparent dielectric, was examined in non-aqueous solvent system. Measurements of sedimentation height and viscosity were conducted to determine proper dispersion condition in the various solvent and dispersant system. Azotropic compound and ethyl acetate were used as the solvent and ammonium-type dispersant was applied to the slurries. All slurries were dispersed well in azotropic solvent system involving 20$\sim$50 vol% ethyl acetate at 2$\sim$3 wt% dispersant content. Especially, dispersion behavior was notably improved in the addition of ethyl acetate in the Bi-based frit slurry.

• 한국세라믹학회지
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• 제28권4호
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• pp.324-328
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• 1991

Monolithic silica gel and glass were prepared from TMOS solution with high concentration of HCl. Appearance of the dried gels and gelation time varied with content of HCl and H2O were observed in the TMOS-CH3OH-HCl-H2O system. The conversion from gel to glass during heat treatment stage was investigated using TG-DTA, XRD, IR and SEM and characteristics of the gel were examined by measuring bulk density, linear shrinkage and Vicker's hardness. A transparent silica glass was prepared from the gel after heat treatment at 1050℃.

• 한국세라믹학회지
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• 제44권10호
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• pp.548-553
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• 2007

Ceramic green sheets consisting Bi-based glass frit were fabricated for an application to PDP transparent dielectric front panel. The dispersion condition of the slurry for tape casting was pre-examined, and two kinds of hinder and plasticizer were used in the non-aqueous slurry system. In the fabrication process for the frit film, the properties such as dry and firing shrinkage, elongation, and transmittance were examined at the condition of various mixing ratio of plasticizers. In the mixing ratio of polyethylene glycol to dibutyl phthalate of 3:5wt%, a good adhesion, elongation and transmittance were observed at the firing temperature of $580^{\circ}C$. The photograph for the cross section of the interface was also showed a dense microstructure.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2004년도 춘계총회 및 연구발표회 초록집
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• pp.47.1-47.1
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• 2004

• 한국결정성장학회지
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• 제6권2호
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• pp.275-285
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• 1996

The effect of heat-treatment on catalytic crystallization in $LI_2O-Al_2O_3-SiO_2$ glass system over its glass transition temperature was investigated. Glass composition $4Li_2O{cdot}22AL_2O_3{cdot}66SiO_2{cdot}2TiO_2{cdot}2.5ZrO_2{cdot}1.5P_2O_5{cdot}1.0Na_2O{cdot}1.0As_2O_3$ (wt%) was selected and heat-treated at different heating conditions to obtain transparent glass-ceramic. Nucleation and crystallization behaviour of this composition were estimated by differential thermal analysis (DTA) and X-ray diffractometer (XRD) and its thermal expansion coefficients were measured by Dilatometer. As a result, glass transition temperature was $730^{\circ}C$ and two maximum nucleation temperatures were estimated at $730^{\circ}C$ and 82$0^{\circ}C$ using JMA(Johson-Mehl-Avrami) equation by DTA. $ZrTiO_4$ $\beta$-Quartz solid solution and $\beta$-Spodumene crystals were identified by XRD. The optimum crystallization temperature was 92$0^{\circ}C$ and three step heating schedule was expected to be useful to obtain transparent glass-ceramic.

• The Korean Journal of Ceramics
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• 제2권1호
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• pp.1-10
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• 1996

Transparent conducting $SnO_2$-based thin films have been coated on float substrates such as fused quartz, and ceramic fiber cloths such as the Nexel and E-glass cloth from tin alkoxides by the sol-gel technique. Also, thin films of alternating layers of $SnO_2$ and $SiO_2$ have been fabricated by dip coating. The sheet resistance and average visible transmittance of the films were investigated in the aspect of the applications as transparent electrodes such as liquid crystal displays, photo-detectors and solar cells. The Nextel and E-glass cloths coated with antimony-doped tin oxide (ATO) had sheet resistance of as low as $20 \;ohm/{\Box}$ and $120ohm/\;{\Box}$, respectively. The promotion effects of additives as $La_2O_3$ and Pt on the ethanol gas sensing properties of the films were investigated in the aspects of the applications as an alcohol sensor and a breath alcohol checker. Possible evidence of quantum well effects in the oxide multilayers of $SnO_2$ and $SiO_2$ was investigated.

• 한국세라믹학회지
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• 제31권4호
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• pp.436-447
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• 1994

ZnO transparent conducting thin film, which is a strong candidate for a transparent electrical contact in optoelectronic devices, was prepared by the vapour spraying method on the slide glass in nitrogen ambient at the atmospheric pressure. The structural, optical and electrical properties of films show a strong dependence on substrate temperature, and the optimum range of deposition temperature existed to obtain TCO(Transparent Conducting Oxide) films. At the higher temperatures, milky films were obtained. In such optimum range, the bandgap in ZnO films was determined from the spectral dependence of absorption coefficient and electrical characteristics were characterized with by the Hall mobility and carrier concentration.

• 한국세라믹학회지
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• 제52권4호
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• pp.290-293
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• 2015

The properties of the IZTO thin films on the glass were studied with a variation of the $SiO_2$ buffer layer thickness. $SiO_2$ buffer layers were deposited by plasma-enhanced chemical vapor deposition (PECVD) on the glass, and the In-Zn-Tin-Oxide (IZTO) thin films were deposited on the buffer layer by RF magnetron sputtering. All the IZTO thin films with the $SiO_2$ buffer layer are shown to be amorphous. Optimum $SiO_2$ buffer layer thickness was obtained through analyzing the structural, morphological, electrical, and optical properties of the IZTO thin films. As a result, the IZTO surface roughness is 0.273 nm with a sheet resistance of $25.32{\Omega}/sq$ and the average transmittance is 82.51% in the visible region, at a $SiO_2$ buffer layer thickness of 40 nm. The result indicates that the uniformity of surface and the properties of the IZTO thin film on the glass were improved by employing the $SiO_2$ buffer layer and the IZTO thin film can be applied well to the transparent conductive oxide for display devices.

• 한국결정성장학회지
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• 제20권1호
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• pp.43-52
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• 2010

삼척 도계지역의 탄광에서 석탄채취시에 발생되는 석탄폐석을 이용하여 유리를 제조하였다. 소다라임계 화학조성을 갖는 유리를 제조하기 위하여 화학원료로서 소다회, 탄산칼슘 등의 원료를 추가로 사용하였고, 화학원료인 탄산칼슘 대신에 천연광물원료인 석회석을 사용하였을 때의 특성을 검토하였다. 전기로를 사용하여 $1,550^{\circ}C$에서 1시간 용응하여 투명한 유리를 제조할 수 있었다. 석탄폐석의 종류 및 파유리의 종류에 따라 다양한 종류의 유리샘플이 제조되었다. 유리샘플의 투과율 및 색차와 같은 광학적 특성을 UV/VIS/NIR Spectrometer를 이용하여 측정하였고, 또한 열팽창계수 및 연화점과 같은 열적특성도 측정하였다. 그 결과, 일반 선탄경석으로는 70% 이상의 가시광선투과율을 갖는 투명한 유리를 제조할 수 있었으며, 또한 쉘(shell) 타입의 선탄경석으로는 0~35%의 가시광선 투과율을 갖는 검정색의 칼라유리를 제조할 수 있었다. 따라서 석탄폐석을 이용하여 건축재료로서 유리타일이나 발포유리와 같은 유리 2차제품을 제조하는데 활용할 수 있으리라 판단되었다.

• 한국세라믹학회지
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• 제27권2호
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• pp.288-296
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• 1990

Parent glasses for the experiments were prepared to be ratio of Li2O : Al2O3 : SiO2=4.5 : 25 : 70.5 as basic components, and TiO2 and ZrO2 in the mixing ratio of 1 : 1 were added as the nucleating agents, whose contents were increased in each sample. DTA, XRD, SEM, IR were observed, and thermal expansion and transmissivities were measured for the crystallized samples under the controlled heat-treatments. The transformation temperatures and the dilatometric softening temperatures in thermal expansion curves, and also the exothermic peaks in differential thermo-analytical curves were shifted to lower temperature. The crystal phase deposited through the heat-treatment was identified as ${\beta}$-quartz solid solution with XRD and IR analysis. The crystalline phases in oopactified samples were ${\beta}$-spodumene coexiting with ${\beta}$-quartz solid solution. The samples having more than 3% nucleating agents were transparent. The crystallized grain sizes were ranged 0.05 to 0.1$\mu\textrm{m}$. The crystallized transparent samples were exceeded 85% in the transmissivity.