• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.315-316
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• 2006

We fabricated GaN nanopores m the etching process of anodic oxidation of aluminum. The aluminum was deposited by using E-beam evaporator on p-type GaN. After the aluminum was anodized GaN structure was exposed to the electric field with the oxidat species. The fabricated nanopore structure provides the enhanced intensity of light emission at the wavelengths 470 nm. We investigated the structure of the GaN nanopores from FE-SEM and EDS measurements.

• Journal of the Korean institute of surface engineering
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• v.49 no.4
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• pp.357-362
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• 2016

In this study, we manufactured the anodized alumina oxide (AAO) template and fabricated the carbon nanofibers and manganese oxide nanofibers using AAO template for application to electrochemical capacitor. Pore diameters of the AAO template were increased from 50 to 90 nm by increasing the acid treatment time after two-step anodizing process. Furthermore nanofibers, which is fabricated by AAO template, showed uniform diameter and micro structure. It is suggested that the surface area is larger than commercial electrode material and it is enhancing the energy density by increasing the specific capacitance.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1143-1146
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• 1993

The magnetic properties of aluminium anodized film in which Co-Fe alloy electrodeposited are investigated with regard to the alloy composition of magnetic films. The electrodeposited Co-Fe particles are confirmed to be single phase Co-Fe alloys by X-ray diffractions. The coercive force as well as the magnetic anisotropy energy can be controlled by changing the composition of the alloy. Magneticfilms having high saturation magnetization and high coercive force were obtained.

• Journal of the Korean institute of surface engineering
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• v.33 no.5
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• pp.309-318
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• 2000

The 6063 Aluminium alloy were electrocolored and anodized at the same time in addition of $CoSO_4$, $FeSO_4$, in the electrolyte and investigated by AES/SAM. It was found that the thickness of anodic oxide film is increased linearly in DC type, and DC combined AC type, the more ratio of anodic Portion in AC, the more increased of anodic film thickness. The color of anodic film was changed from silver to yellow when the increase of the ratio of cathodic portion in AC. Also the increase of $CoSO_4$, $FeSO_4$ in the electrolyte, the coloring time is decreased. From the AES/SAM results, the element of anodic oxide film are Al,O and S. The result of depth profile, the most of the S distributed on the surface and the more S is in DC combined AC type than only DC type.

• Korean Journal of Materials Research
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• v.23 no.11
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• pp.661-665
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• 2013

We investigated the characteristics of electroless plated Cu films on screen printed Ag/Anodized Al substrate. Cu plating was attempted using neutral electroless plating processes to minimize damage of the anodized Al substrate; this method used sodium hypophosphite instead of formaldehyde as a reducing agent. The basic electroless solution consisted of $CuSO_4{\cdot}5H_2O$ as the main metal source, $NaH_2PO_2{\cdot}H_2O$ as the reducing agent, $C_6H_5Na_3O_7{\cdot}2H_2O$ and $NH_4Cl$ as the complex agents, and $NiSO_4{\cdot}6H_2O$ as the catalyser for the oxidation of the reducing agent, dissolved in deionized water. The pH of the Cu plating solutions was adjusted using $NH_4OH$. According to the variation of pH in the range of 6.5~8, the electroless plated Cu films were coated on screen printed Ag pattern/anodized Al/Al at $70^{\circ}C$. We investigated the surface morphology change of the Cu films using FE-SEM (Field Emission Scanning Electron Microscopy). The chemical composition of the Cu film was determined using XPS (X-ray Photoelectron Spectroscopy). The crystal structures of the Cu films were investigated using XRD (X-ray Diffraction). Using electroless plating at pH 7, the structures of the plated Cu-rich films were typical fcc-Cu; however, a slight Ni component was co-deposited. Finally, we found that the formation of Cu film plated selectively on PCB without any lithography is possible using a neutral electroless plating process.

• Applied Chemistry for Engineering
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• v.8 no.5
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• pp.784-789
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• 1997

Aluminium solid electrolytic capacitor in which electroconducting polypyrrole(PPy) is used as an electrolyte is studied. Pyrrole(Py) is electrochemically synthesized using the etched and anodized aluminium foil electrode($Al_2O_3$) as an anode on which the thin layer of chemicalpolymerized PPy as a pre-coating layer is formed previously by chemical oxidative polymerization(CP). Investigating the effects of the polymerization conditions on the electrical characteristics of resulting capacitors, the capacitors which were obtained from the galvanostatic electrolysis of pyrrole containing sodium p-toluenesulfonate(TsONa) under the currents of $2.0{\sim}4.0mA/unit(6.5{\times}10mm)$, showed the most superior properties.

• Korean Journal of Materials Research
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• v.24 no.5
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• pp.259-265
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• 2014

$ZrO_2$ films were coated on aluminum etching foil by the sol-gel method to apply $ZrO_2$ as a dielectric material in an aluminum(Al) electrolytic capacitor. $ZrO_2$ films annealed above $450^{\circ}C$ appeared to have a tetragonal structure. The withdrawal speed during dip-coating, and the annealing temperature, influenced crack-growth in the films. The $ZrO_2$ films annealed at $500^{\circ}C$ exhibited a dielectric constant of 33 at 1 kHz. Also, uniform $ZrO_2$ tunnels formed in Al etch-pits $1{\mu}m$ in diameter. However, $ZrO_2$ film of 100-200 nm thickness showed the withstanding voltage of 15 V, which was unsuitable for a high-voltage capacitor. In order to improve the withstanding voltage, $ZrO_2$-coated Al etching foils were anodized at 300 V. After being anodized, the $Al_2O_3$ film grew in the directions of both the Al-metal matrix and the $ZrO_2$ film, and the $ZrO_2$-coated Al foil showed a withstanding voltage of 300 V. However, the capacitance of the $ZrO_2$-coated Al foil exhibited only a small increase because the thickness of the $Al_2O_3$ film was 4-5 times thicker than that of $ZrO_2$ film.

• Journal of the Korean institute of surface engineering
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• v.1 no.1
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• pp.14.1-18
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• 1967

The characteristics of sulfuric acid anodized layer was studied under various Conbitions, acid concentration : 5-20%, temperature : 5-25$^{\circ}C$, bath voltate : 16 volts , bath agitain : mech agitation : mechanical . The Al+++ ion increase in anodizing baty, the film thickness under microscope, the comparative porosity and the thickness were determined. It was found that film thickness and the porosithy which are the main factors of determining andoized layet quality, rule the corrosing and abrasiion tesistance of the film, and that the porosity is increasing in the outerlayer. The formation mechanism was assumed as follows : The film thickness -increase is due to OH_ ion diffusion into compact non-conductive layer and Al+ + OH_ \longrightarrowAl(OH), Al(OH)+ + OH_ \longrightarrowAl(OH)+$_2$ , Al(OH)+$_2$ + OH_ \longrightarrowAl(OH)$_3$., the strong adhesion force is alse due to Al(OH) or Al(OH)$_2$ in transtion layer. And the pore-nucleation is produced by volume change between Al and Al$_2$O$_3$ and activated H$_2$O gas created by large reaction heat of Al+(x) +OH_ \longrightarrowAl(OH)x.

• Korean Journal of Materials Research
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• v.10 no.5
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• pp.375-381
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• 2000

Aluminium foil for electrolytic capacitors was anodized at the voltage of 100V and 140V for 10 minutes in ammonium adipate solution to form aluminum oxide layer on aluminum substrate as an dielectric film. The thickness, the stoichiometry and the crystal structure of the layer were investigated by using RBS and TEM . In addition EIS technique was employed to study the effects of addition of sulfuric acid on the increment of the foil surface area. It was found that the thickness values of the layers anodized at 100V and 140V were about 130 nm and 190 nm respectively and the stoichiometry of the elements of aluminum and oxygen was 2:3. The anodic oxide layer was shown to be amorphous. but the structure irradiated with electron beam resulted in the transformation into crystalline structure of $${\gamma}$-Al_2$$O_3$ . From a comparison of the impedance results and the capacitance variation to investigate the ef- fects of sulfuric acid addition to the etching bath of hydrochloric acid, the EIS techinque could be useful to analyze the capacitance variation.

• Journal of the Korean Magnetics Society
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• v.14 no.4
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• pp.149-161
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• 2004

The fusion of nano technology and information technology is essential to sustain the present growth rate and to induce new industry in this ever-growing information age. Considering Korean industry whose competitiveness lies heavily on information related technologies, this field will be inevitable for future. Nano materials can be described as novel materials whose size of elemental structure has been engineered at the nanometer scale. Materials in the nanometer size range exhibit fundamentally new behavior, as their size falls below the critical length scale associated with any given property. " Bottom-up' techniques involve manipulating individual atoms and molecules. Bottom-up process usually implies controlled or directed self assembly of atoms and molecules into nano structures. It resembles more closely the processes of biology and chemistry, where atoms and molecules come together to create structures such as crystals or living cells. Nano scale sensors are included in the electronics area since the diverse sensing mechanisms are often housed on a semiconductor substrate and usually give rise to an electronic signal. The application of nano technology to the chemical sensors should allow improvements in functionality such as gas sensing. In this presentation, we will discuss about the nano scale information materials and devices fabricated by using the organic/inorganic nano templates.