• 분석과학
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• 제6권2호
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• pp.225-229
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• 1993

알루미나 강화 지르코니아(10-30ATZ) 제조에 있어 지르코니아(TZ-2Y or TZ-0Y)와 알루미나(AKP-30) 분말 slurry에 2wt% 알루미나에 해당하는 알루미나졸을 첨가한 후 겔화시킴으로써 분말이 고르게 분산되어 있고, 동시에 알루미나겔이 분말의 표면을 코팅함으로써 응집이 일어나는 것을 막았다. 이렇게 제조된 ATZ는 $1450{\sim}1550^{\circ}C$ 이상에서 2시간 소결로 알루미나 grain이 $0.5{\mu}m$ 이하로 잘 분포되어 있는 좋은 미세구조와 이론 밀도의 99% 이상의 소결밀도를 보여 주었다. 또한 20ATZ 부근에서의 $K_{IC}$값은 ${\sim}8MPa{\cdot}m^{1/2}$으로 볼-밀링으로 얻는 $6MPa{\cdot}m^{1/2}$보다 높은 값을 보여주고 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 추계학술대회 논문집 학회본부
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• pp.143-149
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• 1990

A sol-gel processing of $YBa_2Cu_3O_{7-x}$ superconductor using metal nitrate salts and sodium hydroxide as the starting materials has been investigated because of the need to produce pure, hompgeneous superconducting materials. Since the precipitation of barium hydroxides can be obtained only at high basicities, the process has to be carried out Ca. pH 13 to get the simultaneous coprecipitation with the other metal hydroxides. The involved reaction mechanisms were investigated and intermediate and final products were characterized by means of thermogravimetric analysis(TGA), infra-red(IR) spectroscopy, X-ray diffraction(XRD) analysis, scanning electron microscopy(SEM), thermal mechanical analysis(TMA) and electrical measurement.

• 한국세라믹학회지
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• 제28권10호
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• pp.819-823
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• 1991

Pure zirconia ceramic fiber experiences severe volume changes through thermal cyclings of heating and cooling. Zirconia fiber was doped with CaO to stabilize the phase and its effect of CaO was studied on volumetric ratio of each phases, phase transition temperature and microstructure. Tetragonal phase was increased as CaO increases up to 10 mol% and cubic phase was stabilized when CaO was added more than 10 mol%. The average grain size of zirconia fiber was increased as CaO increased and transition temperature was shifted to lower temperature.

• 한국전기전자재료학회논문지
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• 제11권2호
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• pp.128-132
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• 1998

2/65/35 PLZT stock solution prepared by Sol-Gel processing was spin-coated on ITO coated glass and annealed by RTA(Rapid Thermal Annealing). The crystal structure of films was reported based on the observation of crystallization process and microstructure of the film fabricated at different fabrication condition. Films were crystallized into rhombohedral structure by annealing at $750^{\circ}C$ for 5 min. As the annealing temperature increased, the size of rosette structure of the films was grown up from $2.4{\mu}m$ to $15{\mu}m$, dielectric constant was increased, coercive field was decreased 33.82 kV/cm, remnant polarization was increased to 39.84 ${\mu}C/cm^2$ and Optical transmittance was decreased.

• 소성∙가공
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• 제11권7호
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• pp.569-574
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• 2002

Recently, thick PZT films are required for the cases of micro piezoelectric devices with high driving force, high breakdown voltage and high sensitivity, and so on. In this work, thick PZT films were fabricated by Sol-Gel multi-coating method. Microstructures, and electrical properties of films were investigated by XRD, FESEM, impedance analyzer, and P-E hysteresis. PZT films with 2.7$mu extrm{m}$ to 4.4${\mu}{\textrm}{m}$ thickness were fabricated. Dielectric constant, loss, remnant polarization and coercive field of them were 880~1650 at 1kHz, 2~3% at 1kHz, 26~32 $\mu$C/$ extrm{cm}^2$, and 33~60kV/cm, respectively. Also a transverse piezoelectric coefficient $(e_{31,f})$ measurement system was fabricated and tested for thick film samples.

• 대한금속재료학회지
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• 제48권9호
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• pp.831-841
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• 2010

Indium tin oxide (ITO) nanopowders were synthesized by coprecipitation and the sol-gel method to prepare a stable dispersion of ITO nano-colloid for antistatic coating of a display panel. The colloidal dispersions were prepared by attrition process with a vibratory milling apparatus using a suitable dispersant in organic solvent. The ITO coating solution was spin-coated on a glass panel followed by the deposition of partially hydrolyzed alkyl silicate as an over-coat layer. The double-layered coating films were characterized by measuring the sheet resistance and reflectance spectrum for antistatic and antireflective properties.

• Bulletin of the Korean Chemical Society
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• 제21권12호
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• pp.1181-1186
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• 2000

The structural evolution during the thermal treatment of $70SiO_2-3OTiO_2(mole%)$ sol-gel derived powders and films was investigated by FT-IR, Raman and XPS, and XRD. From these results, the $TiO_2-rich$ regions involving $Ti^{4+}$ ions in octahedral coordination were confirmed to be amorphous at $600^{\circ}C$. However, Raman spectra along with XRD patterns indicated that at high temperature (above $700^{\circ}C)$, the amorphous $TiO_2was$ segregating to form anatase crystal. Also, the effect of experimental variables such as thermal treatment, heating rate and exposure to water vapor on structural changes, refractive index and thickness of the film coated on sodalime-silicate glass were investigated.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2003년도 춘계총회 및 연구발표회 초록집
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• pp.169.1-169
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• 2003

• 한국재료학회:학술대회논문집
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• 한국재료학회 2005년도 춘계학술발표대회 및 제8회 신소재 심포지엄 논문개요집
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• pp.308-308
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• 2005

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2002년도 추계총회 및 연구발표회 초록집
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• pp.130.2-130
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• 2002