• 한국진공학회지
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• 제17권2호
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• pp.96-101
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• 2008

MgO는 플라즈마 디스플레이 패널 (Plasma Display Panel, PDP)의 보호막으로 널리 쓰이고 있다. 기존의 산소 이온빔 보조 증착(Ion-Beam-Assisted Deposition, IBAD) 방법을 이용하여 MgO 보호막을 형성시킨 경우 이온빔의 충전에 의해 야기되는 아크(Arc) 문제 등이 있었다. 이 문제점을 해결하기 위하여, 산소 중성빔 보조증착(Neutral-Beam-Assisted Deposition, NBAD) 방법을 이용하여 MgO를 증착하였다. 그리고 산소 중성빔의 에너지를 변화시킴에 따라 MgO 보호막의 특성과 PDP 패널 방전 특성에 미치는 영향을 분석하였다. 이에 따른 실험 결과로부터 산소 중성빔 에너지가 300eV일 때, 최소 방전 개시 전압, 최고 발광 휘도 및 최고 발광 효율을 얻을 수 있었다.

• 한국결정성장학회지
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• 제19권6호
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• pp.324-327
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• 2009

Mg 합금에서 Ca 첨가가 발화 및 연소 특성에 미치는 영향을 조사하였다. 주조 상태에서 순 Mg은 표면과 내부에 균열과 게재물들이 관찰되었지만 Ca이 첨가된 Mg-Ca 합금에서는 관찰되지 않았다. Mg 합금에 Ca가 첨가됨에 따라 1.5 wt%Ca까지는 발화 온도가 급격히 증가하다가 포화되는 경향을 보였다. 이러한 경향은 Mg-Ca 합금에서 Ca의 고용도와 관련이 있었다. Mg-Ca 합금의 연소 표면에 형성된 MgO 산화층이 발화와 연소를 억제하는 역할을 하였다.

• 한국진공학회지
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• 제16권5호
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• pp.338-342
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• 2007

MgO는 플라즈마 디스플레이 패널 (Plasma Display Panel, PDP)의 보호막으로 널리 쓰이고 있다. 본 실험에서는 산소 이온 빔을 이용하여 증착된 MgO 보호막의 특성을 조사하였다. MgO 증착 시 보조 산소 이온 빔의 에너지를 변화시킴에 따라 MgO 보호막의 특성과 PDP 패널 발광특성에 미치는 영향을 분석하였다. 본 연구에서는 산소 이온 에너지가 300 eV 일 때 소자의 방전개시전압이 가장 낮게 나타났고, 발광 휘도 및 발광 효율은 가장 높게 나타났다. 또한 산소 이온 빔의 조사에너지에 따라 MgO 박막의 결정성 및 표면조도가 크게 영향을 받는 것을 확인할 수 있었다. 산소 이온 빔 보조 증착 방법을 이용하여 패널의 발광 휘도와 발광 효율 등 발광특성을 개선하였다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2001년도 추계학술발표회 초록집
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• pp.35-35
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• 2001

agnesium Oxide (MgO) with a NaCI structure is well known to exhibit high secondary electron emission, excellent high temperature chemical stability, high thermal conductance and electrical insulating properties. For these reason MgO films have been widely used for a buffer layer of high $T_c$ superconducting and a protective layer for AC-plasma display panels to improve discharge characteristics and panel lifetime. Up to now MgO films have been synthesized by lE-beam evaporation, Molecular Beam Epitaxy (MBE) and Metalorganic Chemical Vapor Deposition (MOCVD), however there have been some limitations such as low film density and micro-cracks in films. Therefore magnetron sputtering process were emerged as predominant method to synthesis high density MgO films. In previous works, we designed and manufactured unbalanced magnetron source with high power density for the deposition of high quality MgO films. The magnetron discharges were sustained at the pressure of O.lmtorr with power density of $110W/\textrm{cm}^2$ and the maximum deposition rate was measured at $2.8\mu\textrm{m}/min$ for Cu films. In this study, the syntheses of MgO films were carried out by unbalanced magnetron sputtering with various $O_2$ partial pressure and specially target power densities, duty cycles and frequency using pulsed DC power supply. And also we investigated the plasma states with various $O_2$ partial pressure and pulsed DC conditions by Optical Emission Spectroscopy (OES). In order to confirm the relationships between plasma states and film properties such as microstructure and secondary electron emission coefficient were analyzed by X-Ray Diffraction(XRD), Transmission Electron Microscopy(TEM) and ${\gamma}-Focused$ Ion Beam (${\gamma}-FIB$).

• 열처리공학회지
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• 제33권3호
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• pp.129-134
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• 2020

Due to excellent properties such as high specific strength and low density, application of magnesium alloys have been rapidly increased. However, magnesium alloy has a serious problem that is easily oxidized when exposed to high-temperature. For this reason, magnesium alloys have been generally used for SF6 gas such as protective cover gas in casting and melting, but it has been reported that this gas has a serious influence on global warming. Therefore, many researchers have been studied to improve the oxidation resistance of magnesium alloy. It was reported that addition of Be, Ca and CaO in magnesium alloy can improve the oxidation properties. In this study, the possibility of improving the oxidation resistance by adding CaO extracted from oyster shells was investigated. Oyster shells were completely decomposed into CaO and CO₂ by annealing. With the addition of CaO, a coexistence region of MgO + CaO was formed in the oxide layer and its thickness was also reduced.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.364.2-364.2
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• 2014

Magnesium oxide (MgO) thin films have attracted great scientific and technological interest in recent decades. Because of its distinguished properties such as a wide band gap (7.2 eV), a low dielectric constant (9.8), a low refractive index, an excellent chemical, and thermal stability (melting point=$2900^{\circ}C$), it is widely used as inorganic material in diverse areas such as fire resistant construction materials, optical materials, protective layers in plasma display panels, buffer layers of multilayer electronic/photonic devices, and perovskite ferroelectric thin films. Precursor used in the ALD requires volatility, stability, and low deposition temperature. Precursors using a heteroleptic ligands with different reactivity have advantage of selective reaction of the heteroleptic ligands on substrate during ALD process. In this study, we have synethesized new heteroleptic magnesium precursors ${\beta}$-diketonate and aminoalkoxide which have been widely used for the development of precursor because of the excellent volatility, chelating effects by increasing the coordination number of the metal, and advantages to synthesize a single precursor. A newly-synthesized Mg(II) precursor was adopted for growing MgO thin films using ALD.

• 한국주조공학회지
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• 제34권6호
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• pp.194-199
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• 2014

The effect of $Al_2Ca$ on the oxidation resistance and tensile property of Al-5Mg alloys was investigated. According to the TGA (Thermogravimetric analysis) result at $550^{\circ}C$ after 24hrs, the Al-5Mg alloy showed parabolic behavior with weight gain. On the other hand, there was almost no difference in the weight changes of the $Al_2Ca$ added Al-5Mg alloys during the oxidation. It was thought that the improvement of oxidation resistance in $Al_2Ca$ added Al-5Mg alloys might be due to the formation of a protective oxide layer with CaO and MgO on the surface. The microstructures of the alloys showed grain refinement with an increasing $Al_2Ca$ content. From the tensile test, the yield strength of the alloys were improved with an increasing $Al_2Ca$ content. The 0.07 mass%$Al_2Ca$ added Al-5Mg alloy showed similar elongation and increased strength, simultaneously. It was considered that the addition of $Al_2Ca$, which was superior in the oxidation resistance of Al, reduced the formation of Mg oxides and inclusions during the alloying. This, partly led to the improvement of tensile properties.