• Title/Summary/Keyword: Electron spectroscopy

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Elastic and inelastic electron tunneling characteristics in polyimide LB films (Polyimide LB막내의 탄성 및 비탄성 tunneling 전기전도특성)

  • ;;Mitsumasa Iwamoto
    • Electrical & Electronic Materials
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    • v.7 no.6
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    • pp.473-480
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    • 1994
  • The electron tunnel effect in polvimide LB films sandwiched between metal electrodes has been investigated in the present work by a study of both the elastic and inelastic tunneling components. By the results of elastic tunneling experiments in Au/Pl/Au tunneling junction, we can judge the height and thickness of tunnel barrier. The inelastic current in Inelastic Electron Tunneling Spectroscopy(IETS) is due to the interaction of the tunneling electron with the vibrational modes of the molecular species in the barrier. Measurements are done on Au/PI/Pb tunneling junctions. The spectra obtained are the second derivatives of the current-voltage characteristics of these junctions : specifically, d$^{2}$1/dV$^{2}$ as a function of voltage V. Because the energies measured by IETS can be directly compared to those measured by infrared and Raman spectroscopy, IR-RAS spectroscopy also measured for reference.

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Non-Destructive Evaluation for Material of Thermal Barrier Coatings (단열 코팅재료의 비파괴 평가기법)

  • Lee Chul-Ku;Kim Tae-Hyung
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.14 no.1
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    • pp.44-51
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    • 2005
  • Material degradation is a multibillion-dollar problem which affects all the industries amongst others. The last decades have seen the development of newer and more effective techniques such as Focused-ion beam(FIB), Transmission electron microscopy(TEM), Secondary-ion mass spectroscopy(SIMS), auger electron spectroscopy(AES), X-ray Photoelectron spectroscopy(XPS) , Electrochemical impedance spectroscopy(EIS), Photo- stimulated luminescence spectroscopy(PSLS), etc. to study various forms of material degradation. These techniques are now used routinely to obtain information on the chemical state, depth profiling, composition, stress state, etc. to understand the degradation behavior. This paper describes the use of these techniques specifically applied to materials degradation and failure analysis.

Design of an Electron Ohmic-Contact to Improve the Balanced Charge Injection in OLEDs

  • Park, Jin-U;Im, Jong-Tae;Yeom, Geun-Yeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.283-283
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    • 2011
  • The n-doping effect by doping metal carbonate into an electron-injecting organic layer can improve the device performance by the balanced carrier injection because an electron ohmic contact between cathode and an electron-transporting layer, for example, a high current density, a high efficiency, a high luminance, and a low power consumption. In the study, first, we investigated an electron-ohmic property of electron-only device, which has a ITO/$Rb_2CO_3$-doped $C_{60}$/Al structure. Second, we examined the I-V-L characteristics of all-ohmic OLEDs, which are glass/ITO/$MoO_x$-doped NPB (25%, 5 nm)/NPB (63 nm)/$Alq_3$ (32 nm)/$Rb_2CO_3$-doped $C_{60}$(y%, 10 nm)/Al. The $MoO_x$doped NPB and $Rb_2CO_3$-doped fullerene layer were used as the hole-ohmic contact and electron-ohmic contact layer in all-ohmic OLEDs, respectively, Third, the electronic structure of the $Rb_2CO_3$-doped $C_{60}$-doped interfaces were investigated by analyzing photoemission properties, such as x-ray photoemission spectroscopy (XPS), Ultraviolet Photoemission spectroscopy (UPS), and Near-edge x-ray absorption fine structure (NEXAFS) spectroscopy, as a doping concentration at the interfaces of $Rb_2CO_3$-doped fullerene are changed. Finally, the correlation between the device performance in all ohmic devices and the interfacial property of the $Rb_2CO_3$-doped $C_{60}$ thin film was discussed with an energy band diagram.

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A Study on the TiC Coating Using Hollow Cathode Discharge Ion Plating (HCD이온플레이팅 방법을 이용한 zzTiC코팅에 관한 연구)

  • 김인철;서용운;황기웅
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.41 no.8
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    • pp.875-882
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    • 1992
  • Titanium carbide(TiC) films, known as having excellent characteristics of resistance to wear and corrosion, were deposited on SUS-304 sheets using HCD(Hollow Cathode Discharge) reactive ion plating with acetylene gas as the reactant gas. The characteristics of TiC films were examined by X-ray diffraction, micro-Vickers hardness tester, ${\alpha}$-step, SEM(Scanning Electron Spectroscopy), ESCA(Electron Spectroscopy for Chemical Analysis), and AES(Auger Electron Spectroscopy) and the results were discussed with regard to the changes of various deposition conditions(bias voltage, acetylene flow rate, temperature).

Surface Defects States on a SiO2/Si Observed by REELS

  • Kim, Juhwan;Kim, Beomsik;Park, Soojeong;Park, Chanae;Denny, Yus Rama;Seo, Soonjoo;Chae, Hong Chol;Kang, Hee Jae
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.271-271
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    • 2013
  • The defect states of a Ar-sputtered SiO2 surface on Si (001) were investigated using Auger electron spectroscopy (AES) and reflection electron energy loss spectroscopy (REELS). The REELS spectra at the primary electron energy of 500 eV showedthat three peaks at 2.5, 5.1, and 7.2 eV were found within the band gap after sputtering. These peaks do not appear at the primary electron energies of 1,000 and 1,500 eV, which means that the defect states are located at the extreme surface of a SiO2/Si thin film. According to the calculations, two peaks at 7.2 and 5.1 eV are related to neutral oxygen vacancies. However, the third peak at 2.5 eV has never been previously reported and the theories proposed that this defect state may be due to Si-Si bonding. Our Auger data showed that a peak for Si-Si bonding at 89 eV appears after Ar ion sputtering on the surface of the sample, which is consistent with the theoretical models.

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Free-standing graphene intercalated nanosheets on Si(111)

  • Pham, Trung T.;Sporken, Robert
    • Journal of IKEEE
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    • v.21 no.3
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    • pp.297-308
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    • 2017
  • By using electron beam evaporation under appropriate conditions, we obtained graphene intercalated sheets on Si(111) with an average crystallite size less than 11nm. The formation of such nanocrystalline graphene was found as a time-dependent function of carbon deposition at a substrate temperature of $1000^{\circ}C$. The structural and electronic properties as well as the surface morphology of such produced materials have been confirmed by reflection high energy electron diffraction, Auger electron spectroscopy, X-ray photoemission spectroscopy, Raman spectroscopy, scanning electron microscopy, atomic force microscopy and scanning tunneling microscopy.

The Chemical Constituents from Unidentified Sponge (해면의 화학적 성분 연구)

  • Park, Seon Gu;Paul J. Scheuer
    • Journal of the Korean Chemical Society
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    • v.38 no.2
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    • pp.169-173
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    • 1994
  • The previously reported cytotoxic metabolites, against the KB cell line, xestoquinone, halenaquinol sulfate and $halenaquinol^{5,6}$ were isolated from the unidentified sponge collected in October 1992, Manado Bay, Sulawesi in Indonesia. Their structure were elucidated by $^1H-,\;^{13}C$-NMR, $^1H-,\;^{13}C$(1 bond) Heteronuclear Multiple Quantum Coherence Spectroscopy$(HMQC)^1$, $^1H-,\;^{13}C$C(2 and 3 bond) Heteronuclear multiple Bond Correlation Spectroscopy$(HMBC)^2$, Electron Impact Mass Spectroscopy(EI ms), Ultraviolet Spectroscopy(UV), and Infrared Spectroscopy(IR)

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Study on Methods of Enhancement and Measurement of Corrosion Resistance for Subsea Equipment made of Aluminum (알루미늄으로 제작된 심해 장비의 부식 저항 능력 향상 방법 및 측정 방법 조사)

  • Seo, Youngkyun;Jung, Jung-Yeul
    • Plant Journal
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    • v.16 no.3
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    • pp.47-52
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    • 2020
  • This study investigated the methodologies to enhance the corrosion resistance and the ways to measure for subsea equipment made of aluminum. The methodologies for the anticorrosion were cathodic protection, conversion coating, anodizing and organic coating. The simply analyzed ways to measure the corrosion resistance were Scanning Electron Microscope (SEM), Electrochemical Impedance Spectroscopy (EIS), Glow discharge optical emission spectrum spectroscopy (GD-OES), Fourier Transform Infrared Spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), Scanning Vibrating Electrode Technique (SVET), contact angle and interfacial tension. The most widely used tools for increasing the corrosion resistance were the anodizing and the organic coating. Many ways were evenly used to measure corrosion. The methods more frequently utilized were SEM for the surface investigation and the contact angle to evaluate the corrosion resistance.

The Chemical Constituents from the Sponge Spongia sp. (해면 Spongia sp.의 화학적 성분 연구)

  • Park, Sun-Ku;Oh, Chang-Sok;Scheuer, Paul-J.
    • Journal of the Korean Chemical Society
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    • v.39 no.4
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    • pp.301-305
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    • 1995
  • The cytotoxic metabolites, against the KB cell line, halenaquinone, epispongiatriol and aldisin were isolated from the sponge Spongia sp. collected in September 1992, Manado Bay, Sulawesi in Indonesia. Their structures were elucidated by 1H, 13C NMR, 1H 13C(1 bond) Heteronuclear Multiple Quantum Coherence Spectroscopy (HMQC), 1H 13C(2 and 3 bond) Heteronuclear Multiple Bond Correlation Spectroscopy (HMBC), Electron Impact Mass Spectroscopy (EI ms) and Infrared Spectroscopy (IR).

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Analysis of BNNT(Boron Nitride Nano Tube) synthesis by using Ar/N2/H2 60KW RF ICP plasma in the difference of working pressure and H2 flow rate

  • Cho, I Hyun;Yoo, Hee Il;Kim, Ho Seok;Moon, Se Youn;Cho, Hyun Jin;Kim, Myung Jong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.179-179
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    • 2016
  • A radio-frequency (RF) Inductively Coupled Plasma (ICP) torch system was used for boron-nitride nano-tube (BNNT) synthesis. Because of electrodeless plasma generation, no electrode pollution and effective heating transfer during nano-material synthesis can be realized. For stable plasma generation, argon and nitrogen gases were injected with 60 kW grid power in the difference pressure from 200 Torr to 630 Torr. Varying hydrogen gas flow rate from 0 to 20 slpm, the electrical and optical plasma properties were investigated. Through the spectroscopic analysis of atomic argon line, hydrogen line and nitrogen molecular band, we investigated the plasma electron excitation temperature, gas temperature and electron density. Based on the plasma characterization, we performed the synthesis of BNNT by inserting 0.5~1 um hexagonal-boron nitride (h-BN) powder into the plasma. We analysis the structure characterization of BNNT by SEM (Scanning Electron Microscopy) and TEM (Transmission Electron Microscopy), also grasp the ingredient of BNNT by EELS (Electron Energy Loss Spectroscopy) and Raman spectroscopy. We treated bundles of BNNT with the atmospheric pressure plasma, so that we grow the surface morphology in the water attachment of BNNT. We reduce the advancing contact angle to purity bundles of BNNT.

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