• Title/Summary/Keyword: Electrode Evaporation

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A study on the discharge characteristics of liquid nitrogen at atmospheric pressure (대기압하에서 액체질소(LN2)방전특성에 관한 연구)

  • 이영근;주재현;김상구;이광식;이동인
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 1993.10a
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    • pp.58-62
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    • 1993
  • This paper shows the discharge characteristics of liquid nitrogen under plane to plane electrode, needle to plance electrode, inserting teflon insulator in plane to plane electrode at atmospheric pressure. The main experimental device of this paper is cryostat. The important results obtained from this study are sa follows. Breakdown voltage of LN2 under N-P electrode is higher than that of under P-P electrode at atmospheric pressure. Breakdown duration time is longer with increase of electode gap under the P-P, N-P electrodes. The formation of bubbles by evaporation is observed in spite of non-applying source at atmospheric pressure and the creation of corona confirmed. Breakdown voltage and breakdown duration time are in proportion to increase of diameter in case of inserting teflon insulator. Partial discharge characteristics of thickness 0.5[mm] is that 채굼 voltage of teflon insulator rose with increase of diameter in each [pps].

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Electrochemistry and Determination of 1-Naphthylacetic Acid Using an Acetylene Black Film Modified Electrode

  • Huang, Wensheng;Qu, Wanyun;Zhu, Dazhai
    • Bulletin of the Korean Chemical Society
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    • v.29 no.7
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    • pp.1323-1325
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    • 2008
  • The acetylene black (AB) was dispersed into water in the presence of dihexadecyl hydrogen phosphate (DHP) via ultrasonication, resulting in a stable and well-distributed AB/DHP suspension. After evaporation of water, an AB/DHP composite film-modified electrode was prepared. The electrochemical responses of $K_3$[Fe$(CN)_6$] at the unmodified electrode, DHP film-modified electrode and AB/DHP film-modified electrode were investigated. It is found that the AB/DHP film-modified electrode possesses larger surface area and electron transfer rate constant. Furthermore, the electrochemical behaviors of 1-naphthylacetic acid (NAA) were examined. At the AB/DHP film-modified electrode, the oxidation peak current of NAA remarkably increases. Based on this, a sensitive and convenient electrochemical method was proposed for the determination of NAA. The linear range is in the range from $4.0 {\times} 10^{-8}\;to\;5.0 {\times} 10^{-6}$ mol $L^{-1}$, and the detection limit is $1.0 {\times} 10^{-8}$ mol $L^{-1}$. Finally, this new sensing method was employed to determine NAA in several soil samples.

All Solid State Electrochromic (전 고체형 일렉트로크로믹 소자)

  • 채종우;조봉희;김영호
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.05a
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    • pp.295-298
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    • 1996
  • In this study, we have fabricated all solid state electrochromic devices using WO$_3$ film as the working electrode, V$_2$O$\_$5/ film as the counter electrode and PEO-LiClO$_4$-PC film as the solid electrolyte. The WO$_3$ thin films for working electrode and V$_2$O$\_$5/ thin films for counter electrode were deposited onto ITO glass by vacuum evaporation and were shown good electrochromic and state properties after 1x10$\^$5/ cycles. PEO-LiClO$_4$-PC polymer electrolyte can easily be formed into thin films, do not absorb in the visible region of the light. Therefore, such electrolyte have electrochromic properties suitable for large-scale all solid-state electrochromic devices. All solid-staeelectrochromic devices fabricated in this polymer electrolyte have optical modulation of 20%∼30% at 1.5 V.

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Frequency Characteristics of a FBAR using ZnO Thin Film (ZnO 압전박막을 이용한 FBAR의 주파수 응답특성)

  • Do, Seung-Woo;Jang, Cheol-Yeong;Choi, Hyun-Chul;Lee, Yong-Hyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.08a
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    • pp.94-97
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    • 2003
  • This study uses ZnO thin film as a piezoelectric material and Pt as bottom electrode for FBAR (film bulk acoustic resonator) device. ZnO thin film and Pt were deposited by RF-magnetron sputtering method. ZnO thin film and Pt were oriented to c-axis. Top electrode Al was deposited by thermal evaporation. The membrane was formed of bulk micromachining. The FBAR was evaluated by XRD, SEM and electrical characterization. The resonant frequency was measured by HP 8753C Network Analyzer. A fabricated FBAR device exhibited a resonant frequency of 700 MHz ~ 1.5 GHz. When bottom electrode and top electrode thickness were fixed, the resonant frequency was increased as decreasing ZnO thin film thickness.

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Study on the deposition rate and vapor distribution of Al films prepared by vacuum evaporation and arc-induced ion plating (증착방법에 따른 Al 피막의 증착율 및 증기분포에 관한 연구)

  • 정재인;정우철;손영호;이득진;박성렬
    • Journal of the Korean Vacuum Society
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    • v.9 no.3
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    • pp.207-215
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    • 2000
  • Al films on cold-rolled steel sheet have been prepared by vacuum evaporation and arc-induced ion plating, respectively, and the evaporation rate and vapor distribution (thickness distribution over the substrate) have been investigated according to deposition conditions. The arc-induced ion plating (AIIP) method have been employed, which makes use of arc-like discharge current induced by ionization electrode located near the evaporation source. The AIIP takes advantage of high ionization rate compared with conventional ion plating, and can be carried out at low pressure of less than $10^{-4}$ torr. Very high evaporation rate of more than 2.0 mu\textrm{m}$/min could be achieved for Al evaporation using alumina liner by electron beam evaporation. The geometry factor n for the $cos^{n/\phi}$ vapor distribution, which affects the thickness distribution of films at the substrate turned out to be around 1 for vacuum evaporation, while it features around 2 or higher for ion plating. For the ion plated films, it has been found that the ionization condition and substrate bias are the main parameters to affect the thickness distribution of the films.

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A Study on the Surface Characteristics of MgO Layer as the Various Deposition Methods of Electron-beam Evaporation (Electron-beam Evaporation의 증착 방법에 따른 MgO Layer의 표면 특성에 관한 연구)

  • Heo, Jeong-Eun;Lee, Don-Kyu;Cho, Sung-Yong;Lee, Hae-June;Lee, Ho-Jun;Park, Chung-Hoo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.5
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    • pp.468-473
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    • 2008
  • A MgO layer is used as electrode protective film in the alternating current plasma display panel (AC PDP). The properties of MgO layer are thought to be one of the most important factors that affects the panel reliability through the firing voltage variation. In this study, we investigated the relations between the surface characteristics and e-beam evaporation process parameters such as deposition rate, temperature of substrate and distance between the MgO pellet and substrate. To produce the MgO layer of (200) crystal orientation, we suggest the high temperature of the substrate, the long distance between the pellet and substrate and the high deposition rate.

The Coating Materials of Electrode Materials on Machinability of W-EDM (와이어전극의 도금재료가 W-EDM 가공성에 미치는 영향)

  • 김창호;허관도
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.05a
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    • pp.735-738
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    • 2000
  • The characteristics of wire electrical discharge machining (WEDM) are governed by many factors such as the power supply type, operating condition and electrode material. This work deals with the effect of wire electrode materials on the machining characteristics such as, metal removal rate, surface characteristics and surface roughness during WEDM A wire's thermal physical properties are melting point, electrical conductivity and vapor pressure. One of the desired qualities of wire is a low melting point and high vapor pressure to help expel the contaminants from the gap. They are determined by the mix of alloying elements (in the case of plain brass and coated wire) or the base core material(i.e. molybdenum). Experiments have been conducted regarding the choice of suitable wire electrode materials and influence of the properties of these materials on the machinability and surface characteristics in WEDM, the experimental results are presented and discussed from their metallurgical aspect. And the coating effect of various alloying elements(Au, Ag, Cu, Zn, Cr, Mn, etc.) to the Cu or 65-35 brass core on them was reviewed also. The removal rate of some coated wires are higher than that of 65-35 brass electrode wire because the wire is difficult to break due to the wire cooling effect of Zn evaporation latent heat and the Zn oxide on the surface is effective in preventing short circuit. The removal rate increases with increasing Zn content from 35, 40 and Zn coated wire

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Fabrication and Evaluation of the Flexible and Implantable Micro Electrode (생체 삽입형 유연한 마이크로 전극의 제작 및 평가)

  • Baek Ju-Yeoul;Kwon Gu-Han;Lee Sang-Woon;Lee Ky-Am;Lee Sang-Hoon
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.55 no.2
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    • pp.93-99
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    • 2006
  • In this paper, we fabricated and evaluated polydimethylsiloxane(PDMS)-based flexible and implantable micro electrodes. The electrode patterning was carried out with the photolithography and chemical etching process after e-beam evaporation of 100 ATi and 1000 A Au. The PDMS substrate was treated by oxygen plasma using reactive ion etching(RIE) system to improve the adhesiveness of PDMS and metal layers. The minimum line width of fabricated micro electrode was 20 $\mu$m. After finished patterning, we did packaging with PDMS and then brought up the electrode's part about 40 $\mu$m with gold electroplating. The Hank's balanced salt solution(HBSS) test was carried out for 6 month for endurance of fabricated micro electrode. We carried out in-vivo test for the evaluation of biocompatibility by implanting electrodes under the ICR mouse skin for 42 days.

Organic field-effect transistors with step-edge structure

  • Kudo, Kazuhiro
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.91-93
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    • 2008
  • The organic field-effect transistors with step-edge structure were fabricated. Source and drain electrodes were obliquely deposited by vacuum evaporation. The step-edge of the gate electrode serve as a shadow mask, and the short channel is formed at the step-edge. The excellent device performances were obtained.

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Formation of Al2O3 Film by Activated Reactive Evaporation Method (활성화 반응 증발법에 의한 Al2O3 박막 형성)

  • Park, Yong-Gwon;Choi, Jae-Ha
    • Journal of the Korean Society for Heat Treatment
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    • v.14 no.5
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    • pp.292-296
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    • 2001
  • In this work, an ultra-high vacuum activated reactive evaporation equipment was built. With reaction of Al and oxygen plasma, $Al_2O_3$ was deposited on the surface of etched Al foil. The chamber was evacuated down to $2{\times}10^{-7}$ torr initially. The Ar and $O_2$ gas introduced into the chamber to maintain $5{\times}10^{-5}$ torr during deposition. Ar gas prevents recombining of the ionized oxygen. Evaporation was maintained by electron beam evaporator continuously. Heating filament and electrode were used in order to generate plasma. The substrate bias of -300V was introduced to accelerate deposition of evaporated Al atoms. The composition and morphology of deposited $Al_2O_3$ films were analyzed by x-ray photoelectron spectroscopy(XPS) and atomic force microscopy (AFM), respectively. The Al oxide was formed on the surface of etched Al foil. According to AFM results, the surface morphology of $Al_2O_3$ film indicates uniform feature. Dielectric characteristic was measured as a function of frequency. Measured withstanding voltage and capacitance were 52V and $24{\mu}F/cm^2$, respectively. The obtained $Al_2O_3$ film shows clean condition without contaminants, which could be adapted to capacitor production.

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