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

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Surface-Enhanced Raman Scattering of Benzenethiol Adsorbed on Silver-Exchanged Copper Powders

  • Shin, Kuan-Soo;Ryoo, Hyun-Woo;Lee, Yoon-Mi;Kim, Kwan
    • Bulletin of the Korean Chemical Society
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    • v.29 no.2
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    • pp.445-449
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    • 2008
  • Micrometer-sized copper (mCu) powders are weakly surface-enhanced Raman scattering (SERS) active by the excitation at 632.8 nm, but nearly ineffective as a SERS substrate at 514.5 nm excitation. The SERS activity of mCu powders at both excitation wavelengths can be increased dramatically by a simple method of the galvanic exchange reaction with AgNO3 in aqueous medium. In this work, the SERS activity of the Ag-exchanged Cu powders (mCu@Ag) has been evaluated by taking a series of Raman spectra using benzenethiol (BT) as the probe molecule. It is clearly confirmed by field emission scanning electron microscopy and X-ray diffractometry that the SERS activity of mCu@Ag powders is, in fact, highly dependent on the extent of galvanic reaction.

A Study on Graphene Oxide and Carboxylated Styrene-Butadiene Rubber(XSBR) Nanocomposites (그래핀 옥사이드/카르복실화한 스티렌-부타디엔 고무 나노 복합체에 관한 연구)

  • Jang, Sun Ho;Xu, Li Xiang;Cho, Ur Ryong
    • Journal of the Semiconductor & Display Technology
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    • v.16 no.1
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    • pp.52-58
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    • 2017
  • Graphene oxide (GO)/carboxylated styrene-butadiene rubber (XSBR) nanocomposites with various contents of GO were prepared by a latex compounding method. It has been confirmed that the functional groups of GO and the hydrogen bonds between GO and XSBR are existed. It can be seen that the scorch time ($t_{s2}$), which is the measurement of incipient vulcanization of rubber, showed a delay after the addition of GO. Field emission scanning electron microscopy was employed to confirm the uniform dispersion of filler in the matrix. Indeed, with increasing fillers loading, the torque, tensile strength, thermal stability and crosslink density of obtained nanocomposites were improved. These results were correlated to the better dispersion of fillers through the rubber matrix.

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Antennal Sensory Organs in the Female Millipede Orthomorphella pekuensis (Polydesmida: Paradoxosomatidae)

  • Chung, Kyung-Hwun;Moon, Myung-Jin
    • Animal cells and systems
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    • v.10 no.4
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    • pp.183-189
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    • 2006
  • The fine structural characteristics of the antennal sensory organs of a female millipede, Orthomorphella pekuensis, were observed with field emission scanning electron microscopy. On the surface of the antenna, four basic types of sensory receptor with the function of either mechanical or olfactory reception are identified in this female millipede. Of these, chaetiform sensilla (CS) and trichoid sensilla (TS) are related to mechanical reception, and four large apical cone sensilla (AS) and three subtypes of basiconic sensilla ($BS_1,\;BS_2,\;BS_3$) are likely to function in olfactory reception, as these receptors have porous structure commonly. Although this millipede also possess a number of primary or secondary sexual characters to improve the efficiency of reproduction, we could not observe their prominent sexually dimorphic characters in the antennal sensilla with the exception of minor structural and numerical differences.

Metal nano-wire fabrication and properties (금속 나노와이어의 제조와 특성)

  • Hamrakulov, B.;Kim, In-Soo
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2009.05a
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    • pp.432-434
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    • 2009
  • Metal nano-wire arrays on Cu-coated seed layers were fabricated by aqueous solution method using sulfate bath at room temperature. The seed layers were coated on Anodic aluminum oxide (AAO) bottom substrates by electrochemical deposition technique, length and diameter of metal nano-wires were dominated by controlling the deposition parameters, such as deposition potential and time, electrolyte temperature. Anodic aluminum oxide (AAO) was used as a template to prepare highly ordered Ni, Fe, Co and Cu multilayer magnetic nano-wire arrays. This template was fabricated with two-step anodizing method, using dissimilar solutions for Al anodizing. The pore of anodic aluminum oxide templates were perfectly hexagonal arranged pore domains. The ordered Ni, Fe, Co and Cu systems nano-wire arrays were characterized by Field Emission Scanning Electron Microscopy (FE-SEM) and Vibrating Sample Magnetometer (VSM). The ordered Ni, Fe, Co and Cu systems nano-wires had different preferred orientation. In addition, these nano-wires showed different magnetization properties under the electrodepositing conditions.

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Synthesis and Photoactivity of SnO2-Doped TiO2 Thin Films (SnO2가 도핑된 TiO2 박막의 합성 및 광촉매 효과)

  • Jung, Mie-Won;Kwak, Yun-Jung
    • Journal of the Korean Ceramic Society
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    • v.44 no.11
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    • pp.650-654
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    • 2007
  • [ $SnO_2$ ]-doped $TiO_2$ thin films were prepared from tin (IV) bis (acetylacetonate) dichloride and titanium diisopropoxide bis (acetylacetonate) with pluronic P123 or degussa P25 as a structural-directing agent. These hydrolyzed sol were spin coated onto Si(100) wafer substrate. The microstructure, morphology and bonding states of thin films were studied by field-emission scanning electron microscopy (FE-SEM), X-ray diffractometry (XRD), and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of these films was investigated by using indigo carmine solution.

The electrochemical properties of $TiO_2$ photoanode using SBM co-polymer binders (SBM 고분자중합 바인더가 사용된 $TiO_2$ 광전극의 전기화학적 특성)

  • Jin, En-Mei;Park, Kyung-Hee;Gu, Hal-Bon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.360-361
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    • 2008
  • A new kind of SBM co-polymer binder as styrene, n-butyl acrylate, and methacrylic acid (SBM) monodisperse co-polymer binder materials basted on $TiO_2$ pastes was synthesized and this $TiO_2$ pastes were applied of dye-sensitized solar cells (DSSCs). The SBM co-polymer binder was prepared by soap-free emulsion copolymerization using a PEG-EEM macromonomer. The photoanodes were characterized by morphology investigated from field emission scanning electron microscopy (FE-SEM). The photoelectrochemical properties of the thin films and the performance of DSSCs were measured by photovoltaic-current density. DSSC based on the emulsion co-polymer binder was obtained conversion efficiency of 7.1% under irradiation of AM 1.5($100mWcm^{-2}$).

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A Study on Oxygen Precipitation in Heavily Boron Doped Silicon Wafer (고농도 붕소의 도핑된 실리콘 웨이퍼에서의 산소석출에 관한 연구)

  • 윤상현;곽계달
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.9
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    • pp.705-710
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    • 1998
  • Intrinsic gettering is usually to improve wafer quality, which is an important factor for reliable ULSI devices. In order to generate oxygen precipitation in lightly and heavily boron doped silicon wafers with or without high $^75 As^+$ ion implantation, the 2-step annealing method was adopted. After annealing, the were cleaved and etched with th Wright etchant. The morphology of cross section on samples was inspected by FESEM(field emission scanning electron microscopy). The morphology of unimplanted samples was rater rough than that of the implanted. Oxygen precipitation density observed by an optical microscope in lightly boron doped samples was about 3$\times10^6/cm^3$. However, in heavily boron doped samples, the density of oxygen precipitation was largest at $600^{\circ}C$ in 1st annealing, and decreased abruptly until $800^{\circ}C$, But it increased slightly at $1000^{\circ}C$ and was independent with the implantation.

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Properties of AZO Thin Film deposited on the PES Substrate (PES 기판상에 증착된 AZO 박막의 특성)

  • Kim, Sang-Mo;Kim, Kyung-Hwan
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.12
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    • pp.1072-1076
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    • 2007
  • We prepared the Al doped ZnO (AZO) thin film on polyethersulfon (PES) without any substrate heating by Facing Targets Sputtering (FTS) system. FTS system has two different facing targets. One is ZnO doped the content of Al 2 wt% and the other is Zn in order to decrease resistivity. The electrical, structural and optical properties of AZO thin films were investigated. To evaluate the as-deposited thin film properties, we employed four-point probe (CMT-R100nw, Changmin), Surface profiler (Alpha-step, Tencor), UV/VIS spectrometer (HP), X-ray diffractometer (XRD, Rigaku) and Field Emission Scanning Electron Microscopy (FESEM, Hitachi S-4700). As a result, We obtained that AZO thin film deposited on PES substrate at a DC Power of 150 W, working pressure of 1 mTorr and $O_2$ gas flow ratio of 0.2 exhibited the resistivity of $4.2{\times}10^{-4}\;[{\Omega}cm]$ and the optical transmittance of about 85 % in the visible range.

The Dielectric Properties of $Bi_4Ti_3O_{12}$ Ferroelectric Thin Films Doping Neodymium (Neodymium이 첨가된 $Bi_4Ti_3O_{12}$ 강유전체 박막의 유전 특성)

  • Kwon, Hyun-Yul;Nam, Sung-Pill;Lee, Sang-Heon;Bae, Seon-Gi;Lee, Young-Hie
    • Proceedings of the KIEE Conference
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    • 2005.07c
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    • pp.1829-1831
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    • 2005
  • Ferroelectric $Bi_{3.25}Nd_{0.75}Ti_3O_{12}$(BNdT) thin films were proposed for capacitor of FeRAM. The BNdT thin films were grown on Pt/Ti $SiO_2/P-Si(100)$ substrates by the RF magnetron sputtering deposition. The dielectric properties of the BNdT were investigated by varying post-annealing temperatures. Increasing post-annealing temperature, the (117) peak was increased. An increase of rod type grains of BNdT films with increasing post-annealing temperature was observed by the Field Emission Scanning Electron Microscopy(FE-SEM). The dielectric constant and dielectric loss of the BNdT thin films with post-annealing temperature of $700^{\circ}C$ were 418 and 0.37, respectively.

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Resistivity Variation of Nickel Oxide by Substrate Heating in RF Sputter for Microbolometer

  • Lee, Yong Soo
    • Journal of Sensor Science and Technology
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    • v.24 no.5
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    • pp.348-352
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    • 2015
  • Thin nickel oxide films formed on uncooled and cooled $SiO_2/Si$ substrates using a radio frequency (RF) magnetron sputter powered by 200 W in a mixed atmosphere of argon and oxygen. Grazing-incidence X-ray diffraction and field emission scanning electron microscopy are used for the structural analysis of nickel oxide films. The electrical conductivity required for better bolometric performance is estimated by means of a four-point probe system. Columnar and (200) preferred orientations are discovered in both films regardless of substrate cooling. Electric resistivity, however, is greatly influenced by the substrate cooling. Oxygen partial pressure increase during the nickel oxide deposition leads to a rapid decrease in resistivity, and the resistivity is higher in the cooled nickel oxide samples. Even when small microstructure variations are applied, lower resistivity in favor of low noise performance is acquired in the uncooled samples.