• 한국세라믹학회지
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• 제42권3호
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• pp.150-154
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• 2005

Ferroelectric $Bi_{3.35}Sm_{0.65}Ti_{3}O_{12}(BSmT)$ thin films were synthesized by sol-gel process. In this experiments, $Bi(TMHD)_{3},\;Sm_{5}(O^{i}Pr)_{13},\;Ti(O^{i}Pr)_4$ were used as precursors, which were dissolved in 2-methoxyethanol. The BSmT thin films were deposited on the Pt/TiO/SiO/Si substrates by spin-coating. Thereafter, the thin films with the thickness of 240 nm were annealed from 600 to $720^{\circ}C$ in oxygen atmosphere for 1 h, and post-annealed in oxygen atmosphere for 1 h after deposition of Pt electrode to enhance the electrical properties. To investigate the effects of Sm-substitution in the BTO thin films, the BTO and BSmT thin films were prepared, respectively. The remanent polarization and coercive voltage of the BSmT thin films annealed at $720^{\circ}C$ were $19.48{\mu}C/cm^2$ and 3.40 V, respectively.

• 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.

• Journal of Magnetics
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• 제19권3호
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• pp.227-231
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• 2014

We fabricated textured polycrystalline $CoFe_2O_4$ thin films on $Pt(111)/TiO_2/SiO_2/Si$ substrate through a sol-gel method. We varied the thickness of the films, by using precursor solutions with different concentrations of 0.1, 0.2, and 0.3 M, and by depositing 5, 8, or 10 layers on the substrate by spin-coating. X-ray diffraction spectra indicated that when the precursor concentration of the solution was higher than 0.1 M, the spin-coated films were preferentially oriented in the <111> direction. Inspection of the surface morphology by scanning electron microscopy revealed that $CoFe_2O_4$ thin films prepared with 0.2 M solution and 5-time spin-coatings had smoother surface, as compared to the other conditions. Each coating had an average thickness of about 50 nm. The magnetic properties measured by vibrating sample magnetometer showed magnetic anisotropy, as evidenced from the difference in the in-plane and out-of-plane hysteresis loops, which we attributed to the textured orientation of the $CoFe_2O_4$ thin films.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1994년도 추계학술대회 논문집
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• pp.168-170
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• 1994

Pb($Zr_{0.52}$$Ti_{0.48}$)$O_3$ ceramic thin films were fabricated from an alkoxide-based solution by Sol-Gel method. Pb($Zr_{0.52}$$Ti_{0.48}$)$O_3$ ceramic thin films were formed by spin coating method on Pt/$SiO_2$Si substrate at 4000ppm for 30 seconds. The coating process was repeated 6 times and then heat-treated at temperature between 500∼800[$^{\circ}C$] for 1 hour. The final thickness of the thin films were about 4800[A]. The ferroelectric perovskite phases precipitated under the heat-treated at 700[$^{\circ}C$] for 1 hour. Pb($Zr_{0.52}$$Ti_{0.48}$)$O_3$ thin films heat-treated at 700[$^{\circ}C$] for 1 hour showed good dielectric and ferroclectric properties.

• 한국표면공학회지
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• 제32권6호
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• pp.709-716
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• 1999

Ceramic is select for an alternative substrate material for high-speed circuits due to its low-thermal expansion. As, in this study, ceramic was prepared by ISG (interlayer sol-gel) process using metal salts and a metal alkoxide as the starting materials. Generally ceramic substrate is used electroless copper plating for the metallization. But it has been indicate weakely the adhesion strength between the substrate and copper layer. Therefore, this research, using the ISG process on the preparation of homogeneous and possible preparation at law temperature fabricated sol solution. Using of the dip coating method was coated for the purpose of giving the anchoring effect on the coating layer and enhancing the adhesion strength between the $Al_2$O$_3$ substrate and copper layer. This study examined primary the characteristic of the sol making condition and differential thermal analysis (DTA) X-ray diffraction (XRD) were mearsured to identify the crystal phase of heat treatment specimens. The morphology of the coated films were studied by scanning electron microscopy(SEM). As a resurt, XRD analysis was obtained patterns of $\alpha$-cordierite after heat-treatment about 2 hours at $1000^{\circ}C$. SEM analysis could have seen a large number of voids on coated film. The more contants of$ Al_2$$O_3$ Wt% was increased the more voids was advanced. Peel adhesion strength has a maximum in the contants of the TEOS:ANE of 1:0.7 mole%. In this case, adhesion strength has been measured 1150gf, peel adhesion strength were about 10 times more than uncoated of the ceramics film.

• 한국세라믹학회지
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• 제38권9호
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• pp.777-781
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• 2001

$LiCoO_{2}$ thin films have received attention as cathodes of thin film microbatteries in these days. In this study, $LiCoO_{2}$ thin films are fabricated by a sol-gel spin coating method followed by a post-annealing process. The thermal decomposition behaviour of precursor is investigated by TG/DTA analysis. The change of crystallinity, microstructure and electrochemical properties of final films as the drying temperature changes are also studied by XRD, SEM and galvanostatic charge/discharge cycling test. The relationship between the discharge capacity and the drying temperature are intensively investigated in this work.

• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1188-1194
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• 2013

Transparent $TiO_2$ thin films have been prepared by sol-gel spin coating method. The sols used for deposition of thin films were prepared with different ethanol content. The effect of ethanol (solvent) concentration and annealing temperature on the performance of $TiO_2$ thin film solar cells has been studied. The results indicate that the as deposited films are amorphous in nature. $TiO_2$ thin films annealed at temperatures above $350^{\circ}C$ exhibited crystalline nature with anatase phase. The results also indicated that the crystallinity of the films improved with increase of annealing temperature. The high resolution transmission electron microscope images showed lattice fringes corresponding to the anatase phase of $TiO_2$. The band gap of the deposited films has been found to decrease with increase in annealing temperature and increase with increase in ethanol concentration. The dependents of photovoltaic efficiency of the dye-sensitized $TiO_2$ thin film solar cells (DSSCs) with the amount of ethanol used to prepare thin films was determined from photocurrent-voltage curves.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1454-1456
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• 1994

$Pb(Zr_{0.52}Ti_{0.48})O_3$ ceramic thin films were fabricated from an alkoxide-based solution by Sol-Gel method. $Pb(Zr_{0.52}Ti_{0.48})O_3$ ceramic thin films were formed by spin coating method on $Pt/SiO_2/Si$ substrate at 3000rpm for 30 seconds. The coating process was repeated 6 times and then heat-treated at temperature between 500 - $800[^{\circ}C]$ for 1 hour. The final thickness of the thin films were about 4800[A]. The 100% ferroelectric perovskite phases precipitated under the heat treated at $700[^{\circ}C]$ for 1 hour. $Pb(Zr_{0.52}Ti_{0.48})O_3$ thin films heat-treated at $700[^{\circ}C]$ for 1 hour showed good dielectric constant (812) property.

• 한국해양공학회지
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• 제17권3호
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• pp.52-56
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• 2003

This study investigates the photoelectrochemical behavior of STS304 steel with TiO2 thin films coating, applied by sol-gel mehod, for the purpose of cathodic photoprotection of the steel corrosion. One time TiO2-coated STS304 steel, adapted with two kinds of TiO2 sol solution, has the most dominant photopotential abilities, which was -200mV vs. SCE and -500mV vs. SCE under illumination with 40 W fluorescent lamp, respectively. That had yielded more negative values than the corrosion potential of the bare metal(-130mv vs.SCE). The bleaching of TCE was confirmed on TiO2-coated STS304 steel under UV-illumination with 20W Black-light. This Study concluded that Ti02-coated STS304 exhibited both a cathodic photoprotection effect against corrosion and a photocatalytic self-cleaning effect.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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• pp.137-137
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• 2003

Optical amplificator have been used to compensate the losses in the optical signal transmission and processing. Today, there has been increasing demand for the very low cost optical amplifier. Sol-gel offers considerable potential both low cost manufacture, and for great flexibility in materials composition and structure. In addition, the sol-gel process is a very attractive method for producing porous materials with controlled structure. In this work, we present the potoluminescence properties of Er doped A1$_2$O$_3$/SiO$_2$ films. Erbium doped alumina nano sol was prepared by Al(NO$_3$)$_3$.9$H_2O$ and Er(NO$_3$)$_3$.5$H_2O$ through hydrolysis and peptization, and then GPS (3-Glycidoxypropyltrimethoxysilane) was added into Er doped alumina nano sol for organic- inorganic hybridization. Er doped A1$_2$O$_3$/SiO$_2$ film was obtained by spin coating, dip coating and thermal treatment from 30$0^{\circ}C$~120$0^{\circ}C$, and there were crack-free after thermal treatment. The thickness of film was measured SEM, and the porosity of film was characterized by BET and TGA. The crystal phase of Er doped A1$_2$O$_3$/SiO$_2$ were determined by XRD. Finally, the photoluminescence properties of Er doped A1$_2$O$_3$/SiO$_2$ films will be discuss with the consideration of porosity and crystallity.