• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.69-69
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• 2002

• Proceedings of the Korean Ceranic Society Conference
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• 2003.04a
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• pp.219.2-219
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• 2003

• Proceedings of the Korean Vacuum Society Conference
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• 2004.08a
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• pp.155-155
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• 2004

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.47-47
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• 2002

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2162-2166
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• 2013

The tailored surface modification of electrode materials is crucial to realize the wanted electronic and electrochemical properties. In this regard, a dexterous carbon encapsulation technique can be one of the most essential preparation methods for the electrode materials for lithium rechargeable batteries. For this purpose, DL-malic acid ($C_4H_6O_5$) was here used as the carbon source enabling an amorphous carbon layer to be formed on the surface of Si nanoparticles at enough low temperature to maintain their own physical or chemical properties. Various structural characterizations proved that the bulk structure of Si doesn't undergo any discernible change except for the evolution of C-C bond attributed to the formed carbon layer on the surface of Si. The improved electrochemical performance of the carbon-encapsulated Si compared to Si can be attributed to the enhanced electrical conductivity by the surface carbon layer as well as its role as a buffering agent to absorb the volume expansion of Si during lithiation and delithiation.

• Journal of the Korean Vacuum Society
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• v.7 no.3
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• pp.248-254
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• 1998

DLC(Diamond-Like-Carbon) thin film, one of the solid state amorphous carbon films, has been deposited by the method of PECVD (Plasma Enhanced Chemical Vapor Deposition). The structural features have been characterized using both FT-IR Spectroscopy and Raman Scattering. The film is considered to consist of microcrystalline diamond domains and graphitelike carbon domains, which are interconnected by hydrogenated $sp^3$ tetrahedral carbons. This shows a good agreement with the results by I-Vmeasurements. In I-Vstudy, the sudden increase of current has been observed and this phenomenon is understood to be due to the tunneling effect between graphitelike domains. A characteristic feature related to the $\beta$-SiC has been identified in the study of Raman Scattering for the very thin film, which suggests that a buffer layer forms at the interface of the Si substrate and the carbon film.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2304-2308
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• 2010

A $LiNi_{0.8}Co_{0.15}Al_{0.05}O_2$ (LNCAO/C) active material composite cathode was coated with carbon. The conductive carbon coating was obtained by addition of surfactant during synthesis. The addition of surfactant led to the formation of an amorphous carbon coating layer on the pristine LNCAO surface. The layer of carbon coating was clearly detected by FE-TEM analysis. In electrochemical performance, although the LNCAO/C showed similar capacity at low C-rate conditions, the rate capability was improved by the form of the carbon coating at high current discharge state. After 40 cycles of charge-discharge processes, the capacity retention of LNCAO/C was better than that of LNCAO. The carbon coating is effectively protected the surface structure of the pristine LNCAO during Li insertion-extraction.

• Transactions of the Korean hydrogen and new energy society
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• v.12 no.1
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• pp.65-73
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• 2001

Carbon nanotubes were prepared by catalytic decomposition of $CH_4$ using Ni-MgO catalyst at various temperatures. $H_2$ effect on crystallinity and morphology during the synthesis of carbon nanotubes was investigated. The crystallinity and morphology were characterized by SEM, TEM, XRD, TGA, and Raman spectroscopy. In addition, the hydrogen adsorption properties were evaluated by PCT measurement in a hydrogen pressure range between 1 and 120 bar. The optimal synthesis temperature of carbon nanotubes was elevated in the presence of $H_2$, although significant difference of carbon nanotube morphology was not found. It is believed that hydrogen served as self-cleaner mops the amorphous carbon on the catalyst surface. It is proved that the carbon nanotubes have multi-walled structure, short length with a outer diameter of 20 ~40nm and open tips after elimination of the catalyst. The amount of hydrogen adsorbed in carbon nanotubes is increased as the pressure of hydrogen is increased and reaches 1.3 wt % under the hydrogen pressure of 120 bar at room temperature.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.171.1-171.1
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• 2015

Carbon nanotube emitters is very promising electron emitter for electron beam applications. We introduced the carbon nanotube electron beam (C-beam) exposure technic using triode structure. As a source, the electron beam emit from CNT emitters placed at the cathode by high electric field. Through the gate mesh, with high accelerating energy, the electron can be extracted easily and impact at the anode plate. For thin film modification, after the C-beam exposure on the amorphous silicon thin film, we found phase changes and it showed a high crystallinity from the Raman measurement. We expect that this crystallized film will be a good candidate as a new active layer of TFT.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.6
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• pp.782-785
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• 2013

Multi-walled carbon nanotubes were synthesized on Ni catalyst using thermal chemical vapor deposition. By introducing ammonia gas during the CNT synthesis process, clean and vertically aligned CNTs without impurities could be prepared. As the ammonia gas increased a partial pressure of hydrogen in the mixed gas during the CNT synthesis process, we could control the CNT synthesis rate appropriately. As the ammonia gas has an etching ability, amorphous carbon species covering the catalyst particles were effectively removed. Therefore catalyst particles could maintain their catalytic state actively during the synthesis process. Finally, we could obtain clean and vertically aligned CNTs by introducing $NH_3$ gas during the CNT synthesis process.