• The Korean Journal of Ceramics
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• v.4 no.1
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• pp.9-14
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• 1998

Diamond-like carbon(DLC) films were deposited on buffer-layered ZnS substrates by radio frequency plasma enhanced chemical vapor deposition(RF-PECVD) method. Ge and GeC buffer layera were used between DLC and ZnS substrates to promote the adhesion of DLC on ZnS substrates. Ge buffer layers were sputter deposited by RF magnetron sputtering and $GeC^1$ buffer layers were deposited by same method except using acetylene reactive gas. The relatinship between film properties and deposition conditions was investigated using gas pressure, RF power and dc bias voltage as PECVD parameters. The hardness of DLC films were measured by micro Vickers hardness test and the adhesion of DLC films on buffer-layered ZnS substrates were studied by Sebastian V stud pull tester. The optical properties of DLC films on butter-layered ZnS substrates were characterized by ellipsometer and FTIR spectroscopy.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.10
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• pp.1480-1488
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• 2003

Synthesis of carbon nanomaterials on a substrate coated with metal nitrates using an ethylene fueled inverse diffusion flame was illustrated. The effects of radial distance, residence time of the substrate, and hydrocarbon composition on the synthesis of carbon nanomaterials were investigated. The effects of catalyst metal particles were also studied using SUS304 substrates coated with Fe(NO$_3$)$_3$ (ferric nitrate, nonahydrate) and Ni(NO$_3$)$_2$(nickel nitrate, hexahydrate), and Cu substrate. Carbon nanomaterials, with diameters ranging from 30 - 70 nm, were observed on the substrate for both cases of using substrates only and using them with metal nitrates. In case of using the substrate with metal nitrates, the formation and growth of carbon nanomaterials were occurred in the lower temperature region than that of using the substrates only due to the easy activation of the metal particles coated on the surface of the substrates.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.123-126
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• 2001

Multiwalled carbon nanotubes were massively produced by the catalytic reaction of C$_2$H$_2$ - Fe(CO)$\sub$5/ mixture at 750 - 950$^{\circ}C$ in a quartz tube reactor and over quartz substrates. Well-aligned MWNT array grows perpendicular to the quartz tube reactor and the quartz substrates at an average of 60 nm in diameter and up to several thousands of micrometers in length. This method does not require any pretreatment of substrates and CNTs are grown at atmospheric pressure. It could be suitable for mass production of multiwalled nanotubes. Scanning electron microscope and transmission electron microscope images of the nanotubes deposited on the substrates allowed us to monitor the quality of MWNTs grown under different operating conditions.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.954-957
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• 1999

We have synthesized carbon nanotubes by thermal chemical vapor deposition of $C_2$H$_2$ on transition metal-coated silicon substrates. Carbon nanotubes are uniformly synthesized on a large area of the plain Si substrates, different from previously reported porous Si substrates. It is observed that surface modification of transition metals deposited on substrates by either etching with dipping in a HF solution and/or NH$_3$ pretreatment is a crucial step for the nanotube growth prior to the reaction of $C_2$H$_2$gas. We will demonstrate that the diameters of carbon naotubes can be controlled by applying the different transition metals.

• Journal of Ecology and Environment
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• v.37 no.3
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• pp.139-145
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• 2014

Denitrification permanently removes nitrate from aquatic ecosystems, so construction of denitrification walls to enhance denitrification activity is often suggested to reduce the nitrate levels from tributary ecosystems. However, little information is available to guide the choice of appropriate organic materials for increasing denitrification rates in the walls. This study investigated how differences in organic substrates originating from litter and organic materials affected denitrification and carbon mineralization rates in riparian sediments. Potential denitrification rates were highest in riparian sediments that contained large quantities of extractable organic carbon (Ext. Org C) and that had high anaerobic carbon mineralization rates, but they were negatively correlated with C:N ratios. Therefore, this research suggested that the both carbon quantity and quality should be considered when assessing the efficiency of organic substrates to remove nitrate from tributary ecosystems.

• Journal of the Korean Ceramic Society
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• v.41 no.3
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• pp.247-252
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• 2004

노튜브의 길이는 급격히 증가하였지만 촉매금속의 적층방법에 따른 탄소나노튜브의 성장 형태는 큰 차이가 없었다. 특히, ICBD 방법에 의해 Ni 촉매금속을 증착한 경우 다른 방법에 비하여 직선적인 탄소나노튜브가 관찰되었다. ^x Carbon nanotubes were grown on SiO$_2$/Si substrates by applying $C_2$H$_2$ gas through chemical vapor deposition process. It was found that carbon nanotubes were grown successfully on the substrates with catalytic films under 20 $\AA$ total thickness. The increase in reaction temperature from 50$0^{\circ}C$ to 80$0^{\circ}C$ resulted in longer carbon nanotube, but there was no clear tendencies with different types of catalytic layers. It was evident that carbon nanotubes became more straight on the substrate with Ni catalytic film produced by ICBD method.

• Journal of the Semiconductor & Display Technology
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• v.13 no.1
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• pp.7-12
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• 2014

In this study, we investigate the effects of corona-discharge pre-treatment on the properties of carbon nanotubes (CNTs) which are used as flexible transparent electrodes. The CNTs are deposited on PET (polyethylene terephthalate) substrates using a spray coating method. Prior to the deposition of CNTs, the PET substrates are corona-treated by varying the feeding directions of the PET substrate and the numbers of treatments. The variations in the surface morphologies and roughnesses of the PET substrates due to corona-treatment are characterized via atomic force microscopy (AFM). Dynamic contact angles (DCAs) of the corona-treated PET substrates are measured and analyzed as functions of the treatment conditions. Also, the sheet resistances and visible-range transmittances of the CNTs deposited on PET substrates are measured before and after bending test. The experimental results obtained in this study provide strong evidences that the adhesive forces between CNTs and PET substrates can be substantially enhanced by corona-discharge pretreatment.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.1
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• pp.53-59
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• 2003

Using Platinum-silicide (PtSi) formed between silicon substrate and carbon film, we have improved the field emission of electrons from carbon films. Pt films were deposited on n-Si(100) substrates at room temperature by DC sputter technique. After deposition, these PtSi thin films were annealed at 400 ~ $600^{\circ}C$ in a vacuum chamber, and the carbon films were deposited on those Pt/Si substrates by laser ablation at room temperature. The field emission property of C/Pt/Si system is found to be better than that of C/Si system and it is showed that property was improved with increasing annealing temperature. The reasons why the field emission from carbon film was improved can be considered as follows, (1)the resistance of carbon films was decreased due to graphitization, (2)electric field concentration effectively occurred because the surface morphology of carbon film deposited on Pt/si substrates with rough surface, (3)it is showed that annealing induced reaction between Pt film and Si substrate, as a consequence that the interfacial resistance between Pt film and Si substrate was decreased.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.12
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• pp.649-653
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• 2000

We have grown carbon nanotubes by thermal chemical vapor deposition of $C_{2}H_{2}$ on catalytic metal deposited on silicon oxide substrates. Highly purified carbon nanotubes are uniformly grown on a large area of the silicon oxide substrates. It is observed that surface modification of catalytic metals deposited on substrates by either etching with dipping in a HF solution and/or $NH_{3}$ pretreatment is a crucial step for the nanotube growth prior to the reaction of $C_{2}H_{2}$ gas. The diameters of carbon naotubes could be controlled by applying the different catalytic metals.

• Korean Journal of Materials Research
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• v.18 no.5
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• pp.253-258
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• 2008

A simple method to deposit carbon nanotube films uniformly on large area substrates using an arc discharge method is reported in this paper. The arc discharge method was modified to deposit carbon nanotube films in situ on the substrates. The substrates were scanned several times over the arcing point for a uniform film thickness. Deposition was carried out under variable dc bias conditions at 600 torr of $H_2$ gas. The thickness uniformity of the single-wall carbon nanotube films as characterized by a four-point probe was within 30% deviation. The morphology and crystal quality of the single-wall carbon nanotube film were also characterized by field emission scanning electron microscopy and Raman spectroscopy.