• Title/Summary/Keyword: Metal Oxide

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Role of Added Metal Oxide in the Adherence Mechanism of Low Melting Glass to Several Metal Seals (저융점유리와 각종금속과의 봉착기구에 있어서 금속산화물의 역할)

  • 정창주
    • Journal of the Korean Ceramic Society
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    • v.11 no.1
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    • pp.3-9
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    • 1974
  • The role of added metal oxide in the adherence mechanism of low melting glass to several metal plates such as oxygen free high conducting copper, low carbon steel, chrominum galvanized on copper, and stainless steel was investigated. The metal oxide which added to glass were cupric oxide, ferric oxide, chromic oxide, and stainless steel oxide. The glass to that various metla oxide were added, sealed with several metal plates in the electric furnace at $650^{\circ}C$ for 5 minutes. The results as follows; 1) The interfacial reaction was promoted and strong chemical bonding with glass and metals by which the surface energy was decreased showed excellent sealing by addition of metal oxide. 2) When the interfacial reaction of glass and metals was promoted by addition of metal oxide found out that various adhernece mechanism were related to the sealing. 3) When the amount of metal oxide addition was 3-5% the excellent sealing was achieved.

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Conducting Metal Oxide Interdigitated Electrodes for Semiconducting Metal Oxide Gas Sensors

  • Shim, Young-Seok;Moon, Hi-Gyu;Kim, Do-Hong;Jang, Ho-Won;Yoon, Young-Soo;Yoon, Soek-Jin
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.65-65
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    • 2011
  • We report the application of conducting metal oxide electrodes for semiconducting metal oxide gas sensors. Pt interdigitated electrodes have been commonly used for metal oxide gas sensor because of the low resistivity, excellent thermal and chemical stability of Pt. However, the high cost of Pt is an obstacle for the wide use of metal oxide gas sensors compared with its counterpart electrochemical gas sensors. Meanwhile, relatively low-cost conducting metal oxides are widely being used for light-emitting diodes, flat panel displays, solar cell and etc. In this work, we have fabricated $WO_3$ and $SnO_2$ thin film gas sensors using interdigitated electrodes of conducting metal oxides. Thin film gas sensors based on conducting metal oxides exhibited superior gas sensing properties than those using Pt interdigitated electrodes. The result was attributed to the low contact resistance between the conducting metal oxide and the sensing material. Consequently, we demonstrated the feasibility of conducting metal oxide interdigitated electrodes for novel gas sensors.

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Study on the Electrical Conductivity in Polysiloxane/Metal Composite Containing Metal Oxide (금속산화물을 포함한 변성폴리실록산/금속 복합체의 전기 전도성 연구)

  • Im, Hyungu;Kim, Jooheon
    • Applied Chemistry for Engineering
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    • v.20 no.3
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    • pp.307-312
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    • 2009
  • The block-co-polymer type thermosetting polysiloxane coordinated with metal oxide was synthesized to investigate the effect of metal oxide on the dispersity of metal powder in the polysiloxane/metal composite material. The metal powder in the polysiloxane/metal composite materials is better dispersed with metal oxide complex polysiloxane than the case without metal oxide. To understand the effect of quantities of metal oxide on the polysiloxane chain, the various polysiloxanes with different ratios of block unit were synthesized. Electrical conductivity was interpreted by percolation threshold theory to understand the dispersity of dense composite. The behavior of conductivity was in good agreement with theoretical value. The critical value was decreased as the quantities of metal oxide are increased. As a result, as the metal oxide increased on the polymer chain, the dispersity of metal filler was increased.

Improvement of source-drain contact properties of organic thin-film transistors by metal oxide and molybdenum double layer

  • Kim, Keon-Soo;Kim, Dong-Woo;Kim, Doo-Hyun;Kim, Hyung-Jin;Lee, Dong-Hyuck;Hong, Mun-Pyo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.270-271
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    • 2008
  • The contact resistance between organic semiconductor and source-drain electrode in Bottom Contact Organic Thin-Film Transistors (BCOTFTs) can be effectively reduced by metal oxide/molybdenum double layer structure; metal oxide layers including nickel oxide (NiOx/Mo) and moly oxide(MoOx) under molybdenum work as a high performance carrier injection layer. Step profiles of source-drain electrode can be easily achieved by simultaneous etching of the double layers using the difference etching rate between metal oxides and metal layers.

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Annealing for Improving adhesion between Metal layer and Oxide layer (산화막과 금속박막 계면에서의 adhesion 개선을 위한 열처리)

  • 김응수
    • Proceedings of the IEEK Conference
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    • 2002.06b
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    • pp.225-228
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    • 2002
  • The adhesion effect between the oxide layer and the metal layer has been studied by RTP anneal. Two types of oxides, BPSG and P-TEOS, were used as a bottom layer under multi-layered metal film. We observe the interface between oxide and metal layer using SEM (scanning electron microscopy), TEM (transmission electron microscopy), AES (auger electron spectroscopy). Adhesion failure was occurred by interfacial reaction between the BPSG oxide and the multi-layered metal film at 650"C RTP anneal. The phosphorus rich layer was observed at interface between BPSG oxide and metal layer by AES and TEM measurements. On the other hand adhesion was a)ways good in the sample used P-TEOS oxide as a bottom layer. We have known that adhesion between BPSG and multi-layered metal film was improved when the sample was annealed below $650^{\circ}C$.TEX>.

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Contamination structure and process on SUS 316 under UHV, HV and air (초고진공, 고진공, 대기압에서 SUS 316의 오염 구조와 오염 과정 연구)

  • 서지근;이규장;신용현;홍승수;정광화
    • Journal of the Korean Vacuum Society
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    • v.6 no.1
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    • pp.1-8
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    • 1997
  • The contamination structure and process on SUS 316 under various exposure conditions were investigated using x-ray photoelectron spectroscopy. The metal-oxide, metal-H-oxides, CO, COH, and $C_xH_y$ are the main components of contaminants on the SUS surface. The compositional profiles of the contaminants are shown to be $C_xH_y$/CO(COH)/metal-oxide on SUS. The contamination proceeds in two steps. The oxidation of the metallic constituents followed by adsorption of hydrocarbons. Under UHV conditions the contamination is mainly due to the oxidation, and, as the exposure time increases, the oxidation continues. In HV or higher pressure, most of the oxides are formed almost immediately after exposure and as the exposure time increases the contamination of hydrocarbons continues to grow. For the SUS sample exposed to atmosphere, the metal oxide is distributed deep inside the surface with an exponentially decreasing concentration, and its thickness is nearly in the order of photoelectron mean free path. It is also seen that the Fe oxide is segregated over Cr oxide in the highly oxidized samples.

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The Effects of binary metal oxide catalysts for the synthesis of glycerol carbonate (이원계 금속산화물 촉매가 글리세롤카보네이트 합성에 미치는 영향)

  • Baek, Jae-Ho;Moon, Myung-Jun;Lee, Man-Sig
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.1
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    • pp.456-461
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    • 2012
  • The glycerol carbonate was synthesized by glycerol and urea using metal oxide catalysts. The physical properties of the prepared metal oxide catalysts were investigated by X-ray diffraction (XRD), specific surface area analysis (BET), field emission scanning electron microscopy (FE-SEM) and temperature programmed desorption (TPD). In addition, we confirmed the conversion of the glycerol and the yield of the glycerol carbonate according to characteristics of metal oxide catalysts. From XRD and FE-SEM analysis, the crystallite size and crystallinity of metal oxide catalysts decrease with addition of Al. In addition, the Zn-Al mixed metal oxide had higher catalytic activity than the pure ZnO due to decreased side reaction in the synthesis of glycerol carbonate.

Dispersion and Flocculation Behavior of Metal Oxide in Organic Solvent

  • Fujii, Katsuya;Yamamoto, Hideki;Shibata, Junji
    • Proceedings of the IEEK Conference
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    • 2001.10a
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    • pp.353-356
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    • 2001
  • The relation between the flocculation and dispersion of metal oxide powders and the properties of solvents, such as dielectric constant and solubility parameter, was investigated for TiO$_2$, $Al_2$O$_3$and Fe$_2$O$_3$particles. The particle size and median diameter of these metal oxides were measured in many organic solvents, from which the effect of solvents on the flocculation and dispersion of metal oxide powders was considered. The metal oxide powders of TiO$_2$, $Al_2$O$_3$and Fe$_2$O$_3$tend to disperse in a solvent of higher polarity, whereas they are apt to flocculate in a solvent of low dielectric constant, because the Hamaker constant between the particles becomes larger in such a solvent. There we, however, some solvents that do not obey these tendencies. It is possible to evaluate the flocculation and dispersion of these metal oxide powders in many solvents by using numeral balances of Hansen’s three-dimensional solubility parameter (f$_{d}$, f$_{p}$ and f$_{h}$). There exists a solvent giving the optimal dispersion for each metal oxide, and the optimal dispersion point of f$_{d}$, f$_{p}$ and f$_{h}$ is determined by the combination of various metal oxide powders and solvents.nts.nts.nts.

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1-D and 2-D Metal Oxide Nanostructures

  • Son, Yeong-Gu
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.87-88
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    • 2012
  • Metal oxide nanostructures have been applied to various fields such as energy, catalysts and electronics. We have freely designed one and two-dimensional (1 and 2-D) metal (transition metals and lanthanides) oxide nanostructures, characterized them using various techniques including scanning electron microscopy, transmission electron microscopy, X-ray diffraction crystallography, thermogravimetric analysis, FT-IR, UV-visible-NIR absorption, Raman, photoluminescence, X-ray photoelectron spectroscopy, and temperature-programmed thermal desorption (reaction) mass spectrometry. In addition, Ag- and Au-doped metal oxides will be discussed in this talk.

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Revealing Strong Metal Support Interaction during CO Oxidation with Metal Nanoparticle on Reducible Oxide Substrates

  • Park, Dahee;Kim, Sun Mi;Qadir, Kamran;Park, Jeong Young
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.264-264
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    • 2013
  • Strong metal-support interaction effect is an important issue in determining the catalytic ac-tivity for heterogeneous catalysis. In this study, we investigated the support effect and the role of organic capping layers of two-dimensional Pt nanocatalysts on reducible metal oxide supports under the CO oxidation. Several reducible metal oxide supports including CeO2, Nb2O5, and TiO2 thin films were prepared via sol-gel techniques. The structure, chemical state and optical property were characterized using XRD, XPS, TEM, SEM, and UV-VIS spectrometer. We found that the reducible metal oxide supports have a homogeneous thin thickness and crystalline structure after annealing at high temperature showing the different optical band gap energy. Langmuir-Blodgett technique and arc plasma deposition process were employed to ob-tain Pt nanoparticle arrays with capping and without capping layers, respectively on the oxide support to assess the role of the supports and capping layers on the catalytic activity of Pt catalysts under the CO oxidation. The catalytic performance of CO oxidation over Pt supported on metal oxide thin films under oxidizing reaction conditions (40 Torr CO and 100 Torr O2) was tested. The results show that the catalytic activity significantly depends on the metal oxide support and organic capping layers of Pt nanoparticles, revealing the strong metal-support interaction on these nanocatalysts systems.

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