• Title/Summary/Keyword: Protecting layer

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Molecular Dynamics and Quantum Chemical Molecular Dynamics Simulations for the Design of MgO Protecting Layer in Plasma Display Panel

  • Kubo, Momoji;Serizawa, Kazumi;Kikuchi, Hiromi;Suzuki, Ai;Koyama, Michihisa;Tsuboi, Hideyuki;Hatakeyama, Nozomu;Endou, Akira;Takaba, Hiromitsu;Kajiyama, Hiroshi;Shinoda, Tsutae;Miyamoto, Akira
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1049-1052
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    • 2008
  • We developed novel molecular dynamics and quantum chemical molecular dynamics simulators for the design of MgO protecting layer in plasma display panel. These simulators were applied to the investigations on the destruction processes of the MgO protecting layer as well as the evaluation of its second electron emission ability. From the simulation results, we successfully proposed new guidelines for MgO protecting layer with high durability and high second electron emission ability.

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Effect of Needle-Like NiO Protecting Layer on NiCrAl Alloy Foam by Controlled Oxygen Concentration (산소 농도 제어를 통한 NiCrAl 합금 폼 표면의 침상 NiO 보호층 효과)

  • Lee, Young-Geun;Shin, Dong-Yo;Ahn, Hyo-Jin
    • Korean Journal of Materials Research
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    • v.28 no.6
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    • pp.324-329
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    • 2018
  • Needle-like NiO protecting layers on NiCrAl alloy foam, used as support for hydrogen production, are introduced through electroplated Ni and subsequent microwave annealing. To improve the stability of the NiCrAl alloy foam, oxygen concentration of microwave annealing to form a needle-like NiO layer with good chemical stability and corrosion resistance is controlled in a range of 20 and 50 %. As the oxygen concentration increases to 50 %, needle-like NiO forms a dense coating layer on the NiCrAl alloy foam; this layer formation can be attributed to accelerated growth of the (200) plane. In addition, the increased oxygen concentration causes increased NiO/Ni ratio of the resultant coating layer on NiCrAl alloy foam due to improved rate of the oxidation reaction. As a result, the introduction of dense needle-like NiO layers formed at 50 % oxygen concentration improves the chemical stability of the NiCrAl alloy foam by protecting the direct electrochemical reaction between the electrolyte and the foam. Thus, needle-like NiO can be proposed as a superb protecting layer to improve the chemical stability of NiCrAl alloy form.

A Study on the Discharge Characteristics and Optimum Activation Conditions of MgO Thin Film in AC POP (AC PDP의 MgO 활성화 조건과 그 방전 특성에 관한 연구)

  • Kim, Young-Kee;Kim, Suk-Ki;Park, Byung-Yun;Park, Myung-Joo;Cho, Jung-Soo;Park, Chung-Hoo
    • Proceedings of the KIEE Conference
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    • 1998.07e
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    • pp.1758-1760
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    • 1998
  • MgO Protecting layer in AC PDP prevents ion bombardment in discharge plasma. The MgO layer also has the additional importance in lowering the firing voltage due to a large secondary electron emission coefficient. Until now, the MgO protecting layer is mainly prepared by E-beam Evaporation. However, the optimum activation manufacturing process of MgO thin film wasn't well known. Therefore in this study, after MgO protecting layer is prepared on dielectric layer by E-beam evaporation and liquid MgO spin coating, we carried out activation process of MgO thin film as a parameter of Temperature, Operating time and Operating pressure. In addition, discharge characteristics are also studied as a parameter of activation conditions.

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Frirtion and wear properties of plasma-sprayed $Cr_2$$O_3$ composite coatings at high temperature ($MoO_3$가 첨가된 $Cr_2$$O_3$, 플라스마 용사코팅의 고온 마찰 마멸 특성)

  • Lyo, I. W.;Ahn, H.-S.;Lim, D. S.
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2001.11a
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    • pp.96-102
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    • 2001
  • plasma-sprayed Cr$_2$O$_3$-based coatings containing MoO$_3$ were studied to gain a better understanding of the influence of MoO$_3$ composition in the coatings on their tribological behaviour. A reciprocal type tribo-tester was employed to examine friction and wear behavior of the specimens at high temperature(450。C). The physical characteristics of worn surfaces were investigated by scanning electron microscopy and chemical composition of the coating surfaces was analyzed using a X-ray photoelectron spectrometer. The results showed that friction coefficient of the MoO$_3$-added coatings were lower than those without MoO$_3$ addition. The larger protecting layers were observed at the worn surface of plasma spray coated specimens with MoO$_3$ addition. XPS analysis of the protecting layer indicated that MoO$_3$ composition was dominantly formed at the surface. MoO$_3$ composition in the protecting layer appears to be more favorable in reducing the friction.

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Nano-porous $Al_2O_3$ used as a protecting layer of AC Plasma Display Panel

  • Park, Sung-Yun;Hong, Sang-Min;Shin, Bhum-Jae;Cho, Jin-Hoon;Kim, Seong-Su;Park, Sung-Jin;Lee, Kyu-Wang;Choi, Kyung-Cheol
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.359-361
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    • 2003
  • Nano-porous alumina was investigated as a protecting layer in an AC Plasma Display Panel. A 2 ${\mu}m$ thick nano-porous $Al_2O_3$ layer inserted with MgO was formed on the dielectric layer instead of the conventional 500 nm-thick MgO thin film. Both nano-porous $Al_2O_3$layer and inserted MgO were prepared by wet process. The luminance and luminous efficiency of 3-inch test panel adopting nano-porous $Al_2O_3$ was higher than that of the conventional PDP.

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Fabrication of Cr$_2$O$_3$/Mo Composite Powders and Tribological Properties of Plasma-sprayed Coatings (플라즈마 용사용 산화크롬/몰리브덴 복합분말 제조와 용사코팅의 마찰.마멸 특성)

  • 여인웅;안효석;김충현
    • Tribology and Lubricants
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    • v.15 no.2
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    • pp.184-192
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    • 1999
  • Various compositions of$ Cr_2$$O_3$/Mo composite powders were fabricated using spray-drying method and plasma-spray coatings of these powders were prepared to understand their tribological properties. Experiments were conducted using a reciprocal type tribo-tester at room temperature under dry sliding condition. The worn surface of coated specimens were observed using SEM (Scanning Electron Microscopy) and chemical compositions were analyzed using XRD (X-ray Diffractometry) and XPS (X-ray Photoelectron Spectroscopy). The results showed that friction coefficient of the Mo added specimens were lower than that of $Cr_2$$O_3$specimen. However $Cr_2$$O_3$specimen showed the lowest wear loss. Wear protecting layer were observed at the worn surface of coated specimens with Mo addition. From the XPS analysis, the mixed phases of $Cr_2$$O_3$ $CrO_3$and $MoO_3$were founded in the wear protecting layer.

Ultra accelerated molecular dynamics study on electronic structure and luminous efficacy of PDP protecting layer

  • Takaba, Hiromitsu;Serizawa, Kazumi;Suzuki, Ai;Tsuboi, Hideyuki;Hatakeyama, Nozomu;Endou, Akira;Kubo, Momoji;Kajiyama, Hiroshi;Miyamoto, Akira
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.169-172
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    • 2009
  • We developed ultra-accelerated quantum chemical molecular dynamics and characterization simulators for study and design of plasma display panel (PDP) related materials. By use of these simulators, realistic structure of PDP materials is drawn on the computer. Furthermore, based on the structures, various properties such as secondary electron emission coefficient are successfully evaluated. In this report, we will discuss the theoretical secondary electron emission coefficient for several protecting layer materials and the effect of surface structure on the properties based on the result of atomistic simulations.

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The characteristics of anti-erosion for MgO protecting layer in plasma display panel (플라즈마 디스플레이 보호막으로 사용되는 마그네슘 산화막(MgO)의 내식각 특성)

  • 최훈영;이석현
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.2
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    • pp.163-169
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    • 2000
  • In this paper, we showed the erosion characteristic of MgO protector layer releated to lifetime of plasma display panel(PDP). We observed MgO erosion characteristic as a functions of deposition conditions, pressure and distance between electrodes. In RIE condition of Xe gas, the lowest erosion rate appears in the conditions of no heating bias voltage -30V and pressure 5mtorr. In general, as deposition rate increases, erosion rate decreases. In real panel, when the gap distance between electrodes is narrow and the pressure is low, the heavy plasma damage appears. Also, the surfaces between electrodes and on the bus electrode are extremely damaged.

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Electrical and Optical Characteristics of Plasma Display Panel Fabricated by Vacuum In-line Sealing (진공 인라인 실장에 의해 제작된 플라즈마 디스플레이 패널의 전기적ㆍ광학적 특성)

  • Park, Sung-Hyun;Lee, Neung-Hun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.4
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    • pp.344-349
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    • 2005
  • The optical and electrical characteristics of plasma display panel(PDP) using the vacuum in-line sealing technology compared with the conventional sealing process in this research. This PDP consisted of MgO protecting layer by e-beam evaporation and battier rib, transparent dielectric layer, dielectric layer, and electrodes by screen printer and then sealed off on Ne-Xe(4 %) 400 Torr and 430。C. The brightness and luminous efficiency were good as the base vacuum level was higher, and it was to check the advantage of high vacuum level sealing, one of the strong points of the vacuum in-line sealing process. However, the brightness and luminous efficiency was dropped sharply because of a crack on MgO protecting layer by the difference of the expansion and contraction stress on high temperature in the vacuum states between MgO and substrate. Fortunately, the crack was prevented by MgO was deposited on higher temperature than 300。C. Finally, the PDP, was fabricated by the vacuum in-line sealing process, resulted the lower brightness than processing only the thermal annealing treatment in the vacuum chamber, but the luminous efficiency was increased by the reducing power consumption with the decreasing luminous current. The vacuum in-line sealing technology was not to need the additional thermal annealing process and could reduce the fabrication process and bring the excellent optical and electrical properties without the crack of MgO protecting layer than the conventional sealing process.

Friction and Wear Properties of Plasma-sprayed Cr2O3-MoO3Composite Coatings at Room Temperature (MoO3가 첨가된 Cr2O3플라즈마 용사코팅의 상온 마찰 마멸 특성)

  • 여인웅;안효석;임대순
    • Journal of the Korean Ceramic Society
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    • v.39 no.1
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    • pp.79-85
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    • 2002
  • Plasma-sprayed Cr$_2$O$_3$-based coatings containing MoO$_3$were studied to gain a better understanding of the influence of MoO$_3$composition in the coatings on their tribological behaviour. A reciprocal type tribo-tester was employed to examine friction and wear behavior of the specimens at room temperature. The physical characteristics of worn surfaces were investigated by scanning electron microscopy and chemical composition of the coating surfaces was analyzed using a X-ray photoelectron spectrometer. The results showed that friction coefficient of the MoO$_3$-added coatings were lower than those without MoO$_3$addition. However pure Cr$_2$O$_3$coating showed the lowest wear loss at the self-mated test. The larger protecting layers were observed at the worn surface of plasma spray coated specimens with MoO$_3$addition. XPS analysis of the protecting layer indicated that MoO$_3$composition was dominantly formed at the surface. MoO$_3$composition in the protecting layer appears to be more favorable in reducing the friction.