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        검색결과 9

        1.
        2015.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, titanium(Ti) meshes and porous bodies are employed to synthesize carbon nanotubes(CNTs) using methane(CH4) gas and camphene solution, respectively, by chemical vapor deposition. Camphene is impregnated into Ti porous bodies prior to heating in a furnace. Various microscopic and spectroscopic techniques are utilized to analyze CNTs. It is found that CNTs are more densely and homogeneously populated on the camphene impregnated Ti-porous bodies as compared to CNTs synthesized with methane on Ti-porous bodies. It is elucidated that, when synthesized with methane, few CNTs are formed inside of Ti porous bodies due to methane supply limited by internal structures of Ti porous bodies. Ti-meshes and porous bodies are found to be multi-walled with high degree of structural disorders. These CNTs are expected to be utilized as catalyst supports in catalytic filters and purification systems.
        4,000원
        2.
        2012.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present a method of graphene synthesis with high thickness uniformity using the thermal chemical vapor deposition (TCVD) technique; we demonstrate its application to a grid supporting membrane using transmission electron microscope (TEM) observation, particularly for nanomaterials that have smaller dimensions than the pitch of commercial grid mesh. Graphene was synthesized on electron-beam-evaporated Ni catalytic thin films. Methane and hydrogen gases were used as carbon feedstock and dilution gas, respectively. The effects of synthesis temperature and flow rate of feedstock on graphene structures have been investigated. The most effective condition for large area growth synthesis and high thickness uniformity was found to be 1000˚C and 5 sccm of methane. Among the various applications of the synthesized graphenes, their use as a supporting membrane of a TEM grid has been demonstrated; such a grid is useful for high resolution TEM imaging of nanoscale materials because it preserves the same focal plane over the whole grid mesh. After the graphene synthesis, we were able successfully to transfer the graphenes from the Ni substrates to the TEM grid without a polymeric mediator, so that we were able to preserve the clean surface of the as-synthesized graphene. Then, a drop of carbon nanotube (CNT) suspension was deposited onto the graphene-covered TEM grid. Finally, we performed high resolution TEM observation and obtained clear image of the carbon nanotubes, which were deposited on the graphene supporting membrane.
        4,000원
        6.
        2001.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        열화학 기상 증착법을 이용하여 암모니아 처리에 따른 촉매 금속의 표면형태와 탄소 나노튜브의 성장을 조사하였다. 암모니아 처리의 열화학 과정의 조절에 의해 고르게 분산된 수직 성장된 탄소 나노튜브를 얻었다. 탄소 나노튜브 합성시 암모니아처리는 수직성장 및 고밀도 성장에 중요한 과정으로 그 역할에 대해 알아보았다. 고밀도의 수직 배향된 탄소나노튜브의 구조와 형태는 주사전자 현미경과 투과전자 현미경, 라만을 이용하여 관찰하였다.
        4,000원
        9.
        1997.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        TMS(tetramethysilane, Si(CH3)4)를 이용하여 RTCVD(rapid thermal chemical vapor deposition)장치에서 Si(111) 기판 위에 β-SiC(111)를 성장시켰다. 실험변수로는 반응온도, TMS유량, 반응시간, H2유량을 변화시켰으며, XRD, IR, SEM, RBS, TEM등을 이용하여 성장된 박막을 분석하였다. 성장된 박막은 crystallized Si, C또한 Si-H, C-H결합은 관찰할 수 없었으나 다결정이었다. TMS의 유량이 증가함에 따라, 성장온도가 감소함에 따라서 미려한 박막을 성장시킬 수 있었으며, 반응의 활성화에너지는 20kcal/molㆍK이었다.
        4,000원