• Title/Summary/Keyword: field-emission scanning electron microscopy

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A study on high purification of single-walled carbon nanotubes (단층벽 탄소나노튜브의 고순도 정제에 관한 연구)

  • Kim, Jong-Sik;Kim, Gwan-Ha;Kim, Chang-Il
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.11a
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    • pp.122-123
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    • 2005
  • 단층벽 탄소나노튜브(Single-walled carbon nanotube)를 성장시키고 성장된 탄소나노튜브를 여러 단계의 여과과정이 필요 없는 단순한 정제과정을 통하여 비정질 탄소 찌꺼기, 촉매 금속 등의 불순물을 제거하였다. 성장 온도가 증가함에 따라 수율이 증가하고 불순물의 함유량이 적은 탄소나노튜브가 성장이 되었으며 전반적으로 0.41-2.0 nm의 균일한 직경을 가진 SWNT가 합성이 되었으며 정제 후 96% 이상의 순도를 가진 SWNT를 얻을 수 있었다. 전반적으로 실험결과에 대한 물질의 특성 은 field emission scanning electron microscopy (FESEM)와 X-ray diffraction (XRD) 그리고 Raman spectroscopy로 조사하였다.

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Structural Characteristics of $SnO_2$ Thin Films prepared by PECVD (PECVD로 제조한 $SnO_2$ 박막의 구조적 특성)

  • Lee, Jeong-Hoon;Jang, Gun-Eik;Son, Sang-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.11a
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    • pp.250-251
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    • 2005
  • Tin dioxide (SnO$_2$) thin films have been prepared on Si wafer (100) by Plasma Enhanced Chemical Vapor Deposition (PECVD). SnO$_2$ thin films were prepared from mixtures of dibutyltin diacetate as a precursor, oxygen as an oxidant at 275, 325, 375, 425$^{\circ}C$, respectively. The microstructure of deposited films was characterized by X-ray diffraction and field emission scanning electron microscopy. Structural characteristics of prepared SnO$_2$ thin films were investigated with different substrate temperature. The deposition rate was linearly increased with substrate temperature. Surface morphology and uniformity of prepared thin film was excellent at 375$^{\circ}C$ and grain size was averagely 25nm.

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TiN Coatings by Reactive Magnetron Sputtering Under Various Substrate Bias Voltages (기판바이어스 인가에 따른 반응성 마그네트론 스퍼터링에 의한 TiN 코팅)

  • Seo, Pyong-Sup;Chun, Sung-Yong
    • Journal of Surface Science and Engineering
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    • v.41 no.6
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    • pp.287-291
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    • 2008
  • Reactively magnetron sputtered TiN films were deposited on Si wafers under varying bias voltage and characterized by X-ray diffraction, field-emission scanning electron microscopy and Nanoindentation. The films deposited under an Ar + $N_2$ atmosphere exhibited a mixed (200)-(111) orientation with a strong (200) texture, which subsequently changed to a strong (111) texture with increasing bias voltage. The changes in texture and grain size of the TiN thin films are due to one or a combination of factors such as strain energy, surface free energy, surface diffusivity and adatom mobility. The influence of each factor depends on the processing conditions. The average deposition rate and grain size were calculated from FE-SEM images of the films indicating that the deposition rate was lower at the films deposited under bias voltage.

Growth and Structural Characterization of Single Layer Dichalcogenide $MoS_2$

  • Hwang, Jae-Seok;Kang, Dae-Joon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.575-575
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    • 2012
  • Synthesis of novel two dimensional materials has gained tremendous attention recently as they are considered as alternative materials for replacing graphene that suffers from a lack of bandgap, a property that is essential for many applications. Single layer molybdenum disulfide ($MoS_2$) has a direct bandgap (1.8eV) that is promising for use in next-generation optoelectronics and energy harvesting devices. We have successfully grown high quality single layer $MoS_2$ by a facile vapor-solid transport route. As-grown single layer $MoS_2$ was carefully characterized by using X-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy and electrical transport measurement. The results indicate that a high quality single layer $MoS_2$ can be successfully grown on silicon substrate. This may open up great opportunities for the exploration of novel nanoelectronic devices.

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Sputtering of Multifunctional AlN Passivation Layer for Thermal Inkjet Printhead

  • Park, Min-Ho;Kim, Sang-Ho
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.50-50
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    • 2011
  • The aluminum nitride films were prepared by RF magnetron sputtering using an AlN ceramic target. The crystallinity, grain size, Al-N bonding and thermal conductivity were investigated in dependence on the plasma power densities (4.93, 7.40, 9.87 W/$cm^2$) during sputtering. High thermal conductivity is important properties of A1N passivation layer for functioning properly in thermal inkjet printhead. The crytallinity, grain size, Al-N bonding formation and chemical composition were observed using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS), respectively. The AlN thin film was changed from amorphous to crystalline as the power density was increased, and the largest grain size appeared at medium power density. The near stoichiometry Al-N bonding ratio was acquired at medium power density. So, we know that the AlN thin film had better thermal conductivity with crystalline phase and near stoichometry Al-N bonding ratio at 7.40 W/$cm^2$ power density.

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Hydroxyapatite Precipitation Phenomena on Micro-pore Formed Ti-Nb Alloy by PEO technique

  • Kim, Jeong-Jae;Choe, Han-Cheol
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2015.11a
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    • pp.137-137
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    • 2015
  • The purposed of this work was to observe hydroxyapatite precipitation phenomena on micro-pore formed Ti-Nb alloy by PEO technique. The Ti-30Nb and Ti-30Ta alloys were remelted at least ten times in order to avoid inhomogeneity, and then cylindrical specimens (diameter 10 mm, thickness 4 mm) were cut by using laser from cast ingots of the Ti alloys. Heat treatment was carried out at $1050^{\circ}C$ for 2 h for homogenization in argon atmosphere. The morphologic change of the alloys were examined by X-ray diffractometer (XRD) and field emission scanning electron microscopy (FE-SEM).

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Zn/HA Coating on the Ti-xNb Alloys after Nanotube Formation for Dental Implant

  • Byeon, In-Seop;Choe, Han-Cheol
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2015.11a
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    • pp.139-140
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    • 2015
  • Zn/HA coating on the Ti-xNb alloys after nanotube formation for dental lmplant was researched using various experimental methods. Due to g ood biocompatibility and osteoconductivity, hydroxyapatite (HA) coating s on metallic biomedical implants were widely employed in orthopedic and dental applications. To improve biocompatibilities, Zinc (Zn) plays very important roles in the bone formation and immune reg ulations. The nanotube formed Zn-HA films were characterized with X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS).

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m-Aramid Films in Diverse Coagulants

  • Kim, Ji-Young;Jung, Ji-Won;Kim, Sam-Soo;Lee, Jae-Woong
    • Textile Coloration and Finishing
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    • v.21 no.4
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    • pp.63-67
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    • 2009
  • m-Aramid dissolved in N,N-dimethylacetamide (DMAc), were coagulated in different coagulants such as water, methanol, ethanol, propanol and butanol. Various concentrations and temperatures of the coagulants were also used to evaluate dyeing properties of coagulated m-aramid films. Field emission scanning electron microscopy (FE-SEM) was employed to investigate the surface morphology of m-aramid films. Wide angle X-ray diffraction (WAXD) was conducted in order to measure crystallinity change of mcaramid fibers and films. WAXD patterns showed that crystallinity of m-aramid fibers was reduced after film formation. In addition, color depth (K/S value) was measured and the results revealed that the film coagulated in water possessed fairly enhanced color depth.

Surface Characteristics of Hydroxyapatite Coated Surface on Nano/Micro Pore Structured Ti-35Ta-xNb Alloys

  • Jo, Chae-Ik;Choe, Han-Choel
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2014.11a
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    • pp.185-185
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    • 2014
  • In this study, we investigated surface characteristics of hydroxyapatite coated surface on nano/micro pore structured Ti-35Ta-xNb alloys. This paper was focus on morphology and corrosion resistance of Anodic oxidation. To prepare the samples, Ti-35Ta-xNb (x= 0, 10 wt. %) alloys were manufactured by arc melting and heat-treated for 12 h at $1050^{\circ}C$ in Ar atmosphere at $0^{\circ}C$ water quenching. Micro-pore structured surface was performed using anodization with a DC power supply at 280 V for 3 min, nanotube formed on Ti-35Ta-xNb alloys was performed using DC power supply at 30 V in 60 min at room temperature. Surface morphology and structure were examined by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction.

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Synthesis of Carbon Nanowalls by Microwave PECVD for Battery Electrode

  • Kim, Sung Yun;Shin, Seung Kwon;Kim, Hyungchul;Jung, Yeun-Ho;Kang, Hyunil;Choi, Won Seok;Kweon, Gi Back
    • Transactions on Electrical and Electronic Materials
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    • v.16 no.4
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    • pp.198-200
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    • 2015
  • The microwave plasma enhanced chemical vapor deposition (PECVD) system was used to grow a carbon nanowall (CNW) on a silicon (Si) substrate with hydrogen (H2) and methane (CH4) gases. To find the growth mechanism of CNW, we increased the growth time of CNW from 5 to 30 min. The vertical and surficial conditions of the grown CNWs according to growth time were characterized by field emission scanning electron microscopy (FE-SEM). Energy dispersive spectroscopy (EDS) measurements showed that the CNWs consisted solely of carbon.