• Proceedings of the Korean Vacuum Society Conference
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• 2001.02a
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• pp.61-62
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• 2001

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.5
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• pp.801-804
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• 2006

[ $GdAlO_3(GAO)$ ] buffer layer for $YBa_2Cu_3O_{7-{\delta}}(YBCO)$ coated superconductor wire was fabricated by sol-gel processing. Precursor solution was prepared by dissolving 1:1 stoichiometric quantaties of gadolinium nitrate hexahydrate and aluminum nitrate nonahydrate in methanol. The solution was spin-coated on $SrTiO_3(STO)$(100) single crystal substrates and heated at $1000^{\circ}C$ for 2h in wet $N_2-5%\; H_2$, atmosphere. A SEM(scanning electron microscopy) observation of the surface morphology of the GAO layer has shown that it has a faceted morphology indicating epitaxy. It was shown from x-ray diffraction(XRB) that GAO buffer layer was highly c-axis oriented epitaxial thin film with both good out-of-plane($FWHM=0.29^{\circ}$ for the (002) reflection) and in-plane ($FWHM=1.10^{\circ}$ for the {112} reflection) alignment.

• Journal of the Korean Ceramic Society
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• v.54 no.4
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• pp.278-284
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• 2017

In this work, Ta-substituted $Li_7La_3Zr_{2-x}O_{12}$ (LLZTO) powder and pellets with garnet cubic structure were fabricated and characterized by modified and optimized sol-gel synthesis. Ta-substituted LLZO powder with the smallest grain size and pure cubic structure with little pyrochlore phase was obtained by synthesis method in which Li and La sources in propanol solvent were mixed together with Zr and Ta sources in 2-methoxy ethanol. The LLZTO pellets made with the prepared powder showed cubic garnet structure for all conditions when the amount of Li addition was varied from 6.2 to 7.4 mol. All the X-ray peaks of the pyrochlore phase disappeared when the Li addition was increased above 7.0 mol. When the final sintering temperature was varied, the LLZTO pellet had a pyrochlore-mixed cubic phase above $1000^{\circ}C$. However, the surface morphology became much denser when the final sintering temperature was increased. The sol-gel-driven LLZTO pellet with a sintering temperature of $1100^{\circ}C$ showed a lithium ionic conductivity of 0.21 mS/cm when Au was adopted as electrode material for the blocking capacitor. The results of this study suggest that modified sol-gel synthesis is the optimum method to obtain cubic phase of LLZTO powder for highly dense and conductive solid electrolyte ceramics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.165-166
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• 2006

Boron phosphide thin films were prepared on the glass substrate from boron and phosphorous alkoxide precursors by sol-gel processing. Boron phosphide sol with equivalent ratio $(CH_3O_3)B$ : $C_{18}H_{15}P$ = 13 : 2 was selected. Films spin-coated at 4000 rpm for 30 s were coated uniformly. Decomposition and crystallization behavior were examined using DSC/TGA and XRD. The films were sintered at 250, 300 and $400^{\circ}C$. It was determined that crystal structure has a rhombohedral phase. The microstructure of thin film was observed using SEM. Thin films approximately showed a visible ray transmittance of 85 %.

• Analytical Science and Technology
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• v.10 no.3
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• pp.225-229
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• 1997

The stability of Rhodamine 6G Perchlorate(Rh6GP) doped in organically modified silicate(Ormosil) was investigated after the Ormosil was synthesized by sol-gel process. The composition of the Ormosil which makes organic dye molecules stable and dimer-free was decided from comparing absorption peaks of dye molecules in sol state, in wet gel and in completely dried gel. The stable and dimer-free Rh6GP doped in the Ormosil was achieved in the 0.1 molar ratio of HCl/TEOS.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05b
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• pp.107-110
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• 2002

The optical memory devices of BST thin films to composite $(Ba_{0.7}\;Sr_{0.3})TiO_{3}$ using sol-gel method were fabricated by changing of the depositing layer number on $Pt/Ti/SiO_{2}/Si$ substrate. The structural properties of optical memory devices to be ferroelectric was investigated by fractal analysis and 3-dimension image processing. The thickness of BST thin films at each coating numbers 3, 4 and 5 times was $2500[\AA]$, $3500[\AA]$ and $3800[\AA]$. BST thin films exhibited the most pronounced grain growth. The surface morphology image was roughness with coating numbers. The thin films increasing with coating numbers shows a more textured and complex configuration.

• Journal of Magnetics
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• v.19 no.2
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• pp.101-105
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• 2014

In this work, Zinc ferrite nanoparticles have been prepared by various methods, conventional (ZC), mechanochemical processing (ZM) and Sol-Gel (ZS) method, to compare their structural and magnetic properties. The cation distribution obtained from XRD shows the degrees of inversions are 4%, 14.8%, and 16.4% from the normal $ZnFe_2O_4$ structure. Fourier transform infrared spectroscopy (FT-IR) confirms changes in cation distribution of $ZnFe_2O_4$ fabricated by sol-gel and mechanochemical processing. The $^{57}Fe$ M$\ddot{o}$ssbauer spectra of the samples were recorded at room temperature. The spectra exhibit a line broadening. The magnetic properties of the samples were studied by vibration sample magnetometer (VSM) at room temperature and the results show that the sample ZM has ferrimagnetic behaviour.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.5
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• pp.493-497
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• 1999

$TiO_2$ Powders were prepared by sol-gel method to testify the characteristics as the photocatalysts. The relationship between processing conditions (R-value (molar ratio of water to alkoxide)), heat treatment temperature, microstructures (crystalline phases), and properties (surface area, particle size) was examined. The optimal conditionsto improve the activity of photocatalyst for photobleaching of dyes in aqueous solution, Were determined.

• Journal of Ceramic Processing Research
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• v.20 no.1
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• pp.30-34
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• 2019

Copper (Cu)-incorporated silica aerogel was synthesized by a sol-gel process with two-step drying process for color modification. The microstructure of the silica aerogel was not affected significantly by the Cu concentration and an amorphous structure was maintained without any crystalline impurity phases. The textural properties of the silica aerogels investigated by using N2 adsorption-desorption isotherms exhibited the typical features of mesoporous materials. The pore size and porosity were not changed significantly even with the incorporation of Cu up to 1.5 M, which indicates negligible variation of thermal insulating properties. However, the color of the aerogel changed from white and light greenish to dark greenish with increasing Cu content. The color change of the silica aerogel was due to the modification of the electron energy band structure of silica by the Cu atomic levels. Therefore, the color of the silica aerogel powders could be manipulated by incorporating Cu without degrading the thermal insulating properties.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.202-202
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• 2003