• Journal of Powder Materials
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• v.11 no.4
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• pp.328-332
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• 2004

Fe nanopowders were successfully synthesized by plasma arc discharge (PAD) process using Fe rod. The influence of chamber pressure on the microstructure was investigated by means of X-ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FE-SEM), Transmission Electron Microscopy (TEM) and X-ray Photoelectron Spectroscopy (XPS). The prepared particles had nearly spherical shapes and consisted of metallic cores (a-Fe) and oxide shells (Fe$_{3}$O$_{4}$), The powder size increased with increasing chamber pressure due to the higher dissolution and ejection rate of H$_2$ and gas density in the molten metal.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.19.2-19.2
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• 2011

ZnO nanowires have been fabricated by vapor-liquid-solidification with hot-walled pulsed laser deposition method. The diameter of ZnO nanowire has been systematically controlled simply by changing the thickness of Au catalyst. Field effect transistors with different diameter have been fabricated by using photolithography and e-beam lithography. The threshold voltage of ZnO nanowire FET showed enhanced mode and depleted mode depending on the diameter of ZnO nanowires. This is mainly due to the change of the carrier concentration depending on the size of nanowires. We have fabricated ZnO nanowire inverters using nanowire FETs. This simple method to fabricate ZnO nano-inverter will be useful to open the possibility of ZnO nanoelectronic applications.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.9.2-9.2
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• 2011

Ultrathin polyelectrolyte (PE) multilayer films prepared by the versatile layer-by layer (LbL) assembly method have been utilized for the preparation of light-emitting diodes, electrochromic, membrane, and drug delivery system, as well as for selective area patterning and particle surface modification because the various materials with specific properties can be inserted into the film with nano-level thickness irrespective of the size or the shape of substrate. Since the introduction of the LbL technique in 1991 by Decher and Hong, various hydrophilic materials can be inserted within LbL films through complementary interactions (i.e., electrostatic, hydrogen-bonding or covalent interaction). In this study, it is demonstrated that LbL SA multilayer films based on nucleophilic substitution reaction can allow the preparation of the highly efficient magnetic and/or optical films and nonvolatile memory devices.

• Animal Systematics, Evolution and Diversity
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• v.28 no.3
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• pp.208-211
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• 2012

Caminus jejuensis n. sp was collected from depth of 20 m at Geomeunyeo, Seogwipo, Jejudo Island by a SCUBA diving from April 2004 to December 2008. This new species is similar to C. chinensis from China in the composition of spicules except for the spherasters and they differ in spicule size and growth form. This species has longer orthotriaenes and spherules, smaller sterrasters and oxyasters than those of C. chinensis. This species also has many spherasters in choanosome, but C. chinensis lacks. Morever, the new species is a massive shape with wrinkles, whereas C. chinensis is a club shape with smooth surface. Description and figures of the new species are provided.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10b
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• pp.189-192
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• 2003

The Electro-thermal Explosion Coating (EEC) technique is a new surface treatment technology emerged in recent years. It uses an electrical discharge (with very high voltage from 5 to 30 kV or more) to produce a pulse current with large density inside the material to be deposited, the metal wire undergo the heating, melting, vaporization, ionization and explosion processes in a very short time (from tens ns to several hundreds ${\mu}s$), and the melted droplets shoot at the substrate with a very high velocity (3000 - 4500 m/s), so that the coating materials can be deposited on the surface of the substrate. Coatings with nano-size grains or ultra- fine grains can be formed because of rapid solidification (cooling rate up to $10^6-10^9\;k/s$). Surface of the substrate (about $1-5{\mu}m$ in depth) can be melted rapidly and coatings with very high bonding strength can be obtained.

• Current Optics and Photonics
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• v.4 no.1
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• pp.16-22
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• 2020

In high resolution imaging devices, smaller aperture in the color filter causes cross talk which provides incorrect information. Plasmonic color filters (PCFs) have been reported as an alternative of the conventional color resist based-color filter (CRCF) and many studies on PCFs demonstrated the filtering function by PCFs with a sub-micron size. In this work, we investigated the cross talk performance of PCFs compared to CRCFs. The effect of cross talk over distance from the filter were measured for each filter. Despite poorer spectral filtering characteristics, PCFs were more robust against cross talk than CRCFs. Also, the further away from the filter, the more cross talk appeared. As a result, PCFs showed less cross talk than CRCFs at about 82% of the results measured at a distance of 2~10 ㎛. This study will help to make practical use of PCFs in high-resolution imaging applications.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.2
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• pp.80-84
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• 2010

The temperature-programmed reduction of titanium oxide ($TiO_2$) with pure $CH_4$ was used for the preparation of titanium carbide crystallites. The synthesized materials had the different surface areas, indicating that the structural properties of these materials were strong functions of two different heating rates and space velocity employed. The titanium carbide crystallites were active for $NH_3$ decomposition. Since the reactivity varied with changes in the particle size, ammonia decomposition reactivity over the titanium carbides crystallites appeared to be related to the different active species. The reactivities of titanium carbide crystallites were two and three times lower than those of the vanadium and molybdenum carbide crystallites, respectively. These results suggested that the difference in activities might be related to the degree of electron transfer between metals and carbon.

• Journal of Magnetics
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• v.11 no.4
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• pp.156-159
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• 2006

We have studied the magnetic properties of the CuNi nanoparticles for three different sizes prepared by plasma and chemical techniques. The magnetization is enormously enhanced with decreasing the nanoparticle size. This enhanced magnetic moment shows almost inversely linear temperature dependence, which could be interpreted by the Langevin-type superparamagnetism. The field dependence exhibits ferromagnetic-like behavior with weak hysteresis, which could described in terms of uncompensated spin and/or surface anisotropy. In addition, the magnetic data suggest that the CuNi nanoparticles produced by the plasma method result in significantly less oxidized metallic nanoparticles than those prepared by other techniques.

• Proceedings of the Korean Magnestics Society Conference
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• 2014.05a
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• pp.17-18
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• 2014

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.989-992
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• 2008

X-ray lithography is one of the most powerful processes in the fabrication of nano/micro structures with a high aspect ratio. This process enables the fabrication of ultra-thin barrier ribs for PDP using X-ray sensitive paste. In this paper, organic material including photo-monomers, photo-oligomers, binder polymer and additives as well as inorganic powders with different size were optimized to fabricate high aspect ratio barrier rib pattern for PDP.