• Transactions on Electrical and Electronic Materials
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• v.4 no.5
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• pp.6-9
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• 2003

Electrophoretic deposition (EPD) of alcohol YBCO suspensions on the Ag wire electrode is studied. Polyethyleneglycol was coordinated to a structure formed by the EPD process with YBCO particles. The d.c electric fields of 200-300 V/cm are applied for 1-10 min. The optimal condition for the EPD allows modifying the properties and microstructure of the deposited films. Superconducting coatings with nanometer-sized pores and a preferred orientation along the caxis were prepared from the result with chemically modified precursor solution. In contrast, YBCO coatings of submicrometer-sized pores and randomly orientated grains were prepared from the solution without PEG.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05a
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• pp.117-122
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• 2004

Electrophoretic deposition (EPD) of alcohol YBCO suspensions on the Ag wire electrode was studied. Poly(ethylene glycol) was coordinated to a structure formed by the EPD process with YBCO particles. The suspension is characterized in terms of zeta potential and conductivity. The d.c electric fields of 200-300V/cm are applied for 1-10 min. The optimal condition for the EPD allows modifying the properties and microstructure of the deposited films. Superconducting coatings with nanometer-sized pores and a preferred orientation along the c-axis were prepared from the result with chemically modified precursor solution. In contrast, YBCO coatings of sub-micrometer sized pores and randomly orientated grains were prepared from the solution without PEG

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.406-407
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• 2007

We prepared indium zinc oxide (IZO) thin film for cathode electrode such as an application of flat panel display by using the facing targets sputtering (FTS) method at room temperature. The effects of input power and film thickness were investigated with respect to physical and optical properties of films such as deposition rate, electrical properties, microstructure and transmittance. We could obtain properties of IZO thin films of under $10^{-3}\;{\Omega}-cm$ in resistivity and the thin films of over 90% in transmittance. Also, we obtained IZO thin films which were an amorphous structure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.244-247
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• 1999

The(Sr$\sub$0.85/Ca$\sub$0.15/) TiO$_3$(SCT) thin films are deposited on Pt-coated electrode(Pt/TiN/SiO$_2$/Si) using RF sputtering method. The composition of SCT thin films deposited on Si substrate at room temperature is close to stoichiometry(1.102 in A/B ratio). Also, SCT thin films deposited on Pt-coated electrodes have the cubic perovskite structure and polycrystalline state. The maximum dielectric constant of SCT thin films is obtained by annealing at 600[$^{\circ}C$].The dielectric constant changes almost linearly in temperature ranges of -80~+90[$^{\circ}C$].

• Journal of Welding and Joining
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• v.20 no.1
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• pp.55-61
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• 2002

The automobile is made up of about twenty thousand parts. Some parts are formed by pressing and combined by spot welding. Among them, steel palate of fuel tank is formed in the metal mold and bending parts are jointed by spot and seam welding. To find weldability conditions of spot welding, clearance between two welding steel plates was made and after spot welding, weldability is evaluated by means of tensile shear load, nugget size and shape. Specimen used in this study was a mild steel of 1.2mm thickness and electrode was Cu-Cr alloy of 6mm diameter. When spot welding started, the clearance of two steel plates was changed 0mm, 3mm and 5mm step by step. The fractured surface of specimen after this test was observed by Optical Microscope to measure microstructure and nugget shape. When clearance of two specimen was 3mm and 5mm, strength and nugget size was decreased and nugget shape was not clear.

• Journal of Electrochemical Science and Technology
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• v.10 no.1
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• pp.82-88
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• 2019

Here, we report on nanocrystalline Si-Al-M (M = Fe, Cu, Ni, Zr) alloys for use as an anode for lithium-ion batteries, which were fabricated via a melt-spinning method. Based on the XRD and TEM analyses, it was found that the Si-Al-M alloys consist of nanocrystalline Si grains surrounded by an amorphous matrix phase. Among the Si-Al-M alloys with different metal composition, Ni-incorporated Si-Al-M alloy electrode retained the high discharge capacity of 2492 mAh/g and exhibited improved cyclability. The superior $Li^+$ storage performance of Si-Al-M alloy with Ni component is mainly responsible for the incorporated Ni, which induces the formation of ductile and conductive inactive matrix with crystalline Al phase, in addition to the grain size reduction of active Si phase.

• Progress in Superconductivity and Cryogenics
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• v.8 no.4
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• pp.19-21
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• 2006

Biaxially textured Ni was fabricated by electrodeposition process and delaminated from the biaxially textured cathode surface for further buffer layer deposition process. Those electrode posited Ni substrates showed well-developed biaxial texture and smooth surface. In order to improve the thermal stability of Ni substrates, Mn was alloyed by adding Mn precursor into the electrodeposition bath. Subsequently, $CeO_2$ buffer layers are deposited by MOD process to prevent interfacial reaction between superconductor and substrates. In particular, Bismuth oxide was added to $CeO_2$ to realize lower temperature processing of buffer layers. The microstructure and texture development of each layers have been investigated. Preliminary results shows that all electro/chemical process can be a candidate for cost effective route to YBCO coated conductor.

• Journal of the Korean Vacuum Society
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• v.9 no.2
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• pp.162-166
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• 2000

High quality $Si_3N_4$ metal-insulator-metal (MIM) capacitors were realized by plasma enhanced chemical vapor deposition (PECVD). Titanium nitride (TiN) adapted as a diffusion barrier reduced the interfacial reaction between $Si_3N_4$ dielectric layer and aluminum metal electrode showing neither hillock nor observable precipitate along the interface. The capacitance and the current-voltage characteristics of the MIM capacitors showed that the minimum thickness of $Si_3N_4$ layer should be limited to 500 $\AA$ under the present process, below which most of the capacitors were electrically shorted resulting in the devastation of on-wafer yield. According to the transmission electron microscopy (TEM) on the cross-sectional microstructure of the capacitors, the dielectric breakdown was caused by slit-like voids formed at the interface between TiN and $Si_3N_4$ layers when the thickness of $Si_3N_4$ layer was less than 500 $\AA$. Based on the calculation of thermally-induced residual stress, the formation of voids was understood from the mechanistic point of view.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.6
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• pp.289-294
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• 2010

Ni-YSZ (Yttria Stabilized Zirconia) composite powders for SOFC were fabricated by glycine nitrate process. $ZrO(NO_3)_2{\cdot}2H_2O$, $Y(NO_3)_3{\cdot}6H_2O$, $Ni(NO_3)_2{\cdot}6H_2O$ and glycine were chosen as the starting materials. The structural properties of the sintered Ni-YSZ cermets have been investigated with respect to the volume contents of Ni. A porous microstructure consisting of homogeneously distributed Ni and YSZ phases together with well-connected grains was observed. The sintered Ni-YSZ cermets showed a porous microstructure consists of homogeneously distributed Ni and YSZ phases and the grains were well-connected. It was found that the open porosity is sensitive to the volume content of Ni. The Ni-YSZ cermet containing 35 vol% Ni seems to be suitable for the electrode material of SOFC since it provides sufficient open porosity higher than 30%.

• Journal of the Korean Ceramic Society
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• v.41 no.3
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• pp.229-234
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• 2004

In this study, we proposed new forming process for a porous ceramic body with unique pore structure. h tubular-type porous NiO-YSZ body with radially aligned pore channels was prepared by freeze-drying of aqueous slurry. A NiO-YSZ slurry was poured into the mold, which was designed to control the crystallization direction of the ice, followed by freezing. Thereafter the ice was sublimated at a reduced pressure. SEM observations revealed that the NiO-YSZ porous body showed aligned large pore channels parallel to the ice growth direction, and fine pores are formed around the outer surface of the tube. It was considered that the difference in the ice growth rate during the freezing process resulted in such a characteristic microstructure. Bilayer consisting of dense thin electrolyte film of YSZ onto the tubular type porous body has been successfully fabricated using a slurry-coating process followed by co-firing. It was regarded that the obtained bilayer structure is suitable for constructing electrode-support type electrochemical devices such as solid oxide fuel cells.