• 한국세라믹학회지
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• 제25권6호
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• pp.593-600
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• 1988

The properties of 10 kinds of MgO clinker were investigated to know the effect of MgO clinker's porperties on corrosion of MgO-C brick. For MgO clinker, chemical composition, porosity, density, periclase grain size, and microstructure were examined, while slag corrosion resistance was examined for MgO-C brick. In MgO clinker pore size and it's distribution, periclase grain size, impurities composition and the composition of grain boundaries are more important factors to determine corrosion degree of MgO-C brick than density, potosity and MgO purity.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.181-183
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• 2009

Comparative study of the dependence of the firing voltage of MgSrO and MgCaO protective layers on chemical composition was carried out. It was observed that the firing voltage increases when CaO/MgO or SrO/MgO ratio increases.

• 한국재료학회지
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• 제9권5호
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• pp.441-445
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• 1999

Alkaline earth metal oxides were added to the conventional MgO films as a protective layer for dielectric materials to have lower firing voltage(Vf) of the plasma display panel(PDP). Panels with various protective layers of MgO-alkaline earth metal oxides were prepared on glass by using e-beam evaporation and its effect on firing voltage characteristics were investigated. (Ba-Mg)O films had poor voltage characteristics because of higher activation energy of BaO. But, (Sr-Mg)O, (Ca-Mg)O and (Ca-Sr-Mg) O had better voltage characteristics than the conventional MgO. A mixture film of (Mg-Ca-Sr)O show the lowest firing voltage which is less than that of MgO by 20V. The chemical composition to have lowest firing voltage is MgO:SrO:CaO ratio of 6:2:2. The mixture of MgO-Alkaline earth metal oxides films showed good transmittance properties within the visual range.

• 한국세라믹학회지
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• 제47권2호
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• pp.163-168
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• 2010

Effects of compositions on the microwave dielectric properties of the MgO-$TiO_2$ system were investigated as a function of the molar ratio of MgO to $TiO_2$ ($0.9{\leq}MgO/TiO_2\;(x){\leq}1.2$). With the compositional changes, secondary phases of $MgTi_2O_5$ and $Mg_2TiO_4$ were also detected along with $MgTiO_3$. Microwave dielectric properties of the specimens were dependent on the types of phases developed in the sintered specimens. A single phase of $MgTiO_3$ showed a dielectric constant (K) of 18.2, a quality factor (Qf) of 198,000 GHz, and a temperature coefficient of resonant frequency (TCF) of $-51\;ppm/^{\circ}C$. However, the dielectric properties of the specimens with a secondary phase of $MgTi_2O_5$ (K=19.9, Qf=48,000 GHz) and/or $Mg_2TiO_4$ (K=15.6, Qf=56,000 GHz) were worsened. Dependence of the microwave dielectric properties on the secondary phase of the MgO-$TiO_2$ system was also discussed in terms of dielectric mixing rules.

• 한국세라믹학회지
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• 제20권1호
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• pp.37-42
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• 1983

An attempt was made to derive a possible synthetic mechanism of Fluoro-phlogopite (Mica, 4Mg.$Al_2O_3$.$6SiO_2$.$K_2O$.$2MgF_2$) The pevention of fluorine vaporization turned out to be the key in the synthesis of Mica in question.l Consequently the quinary system of Mica was seperately synthesized ; frist 4MgO.$Al_2O_3-6SiO_2$(ternary system) was sintered at 135$0^{\circ}C$ and $K_2O$ and $MgF_2$ were added and second 4MgO.$Al_2O_3-6SiO_2$.$K_2O$ (quarternary system) was heat-treated at 135$0^{\circ}C$ and $MgF_2$ was added. The ternary system resulted in Proto-enstatite Cordierite and Spinel phases while Forsterite and Leucite were shown in the quarternay system . In both methods Fluoro-phlogopite was systhesized but the solid state reactions to form Mica from the ternary system and the quarternary system were different. High temperature reactions in the formation of Mica were investigated employing XRD, DTA and SEM The study of the synthesis of Mica indirectly suggested a method of phase analysis of quinary system(MgO-$Al_2O_3-SiO_2-K_2O-MgF_2$) and quarternary system(MgO-$Al_2O_3-SiO_2-K_2O-MgF_2$) at various temperatures.

• Bulletin of the Korean Chemical Society
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• 제34권11호
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• pp.3367-3371
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• 2013

MgO nanorods were fabricated by the thermal evaporation of $Mg_3N_2$. The influence of ZnO sheathing and hydrogen plasma exposure on the photoluminescence (PL) of the MgO nanorods was studied. PL measurements of the ZnO-sheathed MgO nanorods showed two main emission bands: the near band edge emission band centered at ~380 nm and the deep level emission band centered at ~590 nm both of which are characteristic of ZnO. The near band edge emission from the ZnO-sheathed MgO nanorods was enhanced with increasing the ZnO shell layer thickness. The near band edge emission from the ZnO-sheathed MgO nanorods appeared to be enhanced further by hydrogen plasma irradiation. The underlying mechanisms for the enhancement of the NBE emission from the MgO nanorods by ZnO sheathing and hydrogen plasma exposure are discussed.

• 청정기술
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• 제21권1호
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• pp.39-44
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• 2015

본 연구에서는 다섯 종의 씨앗(춘채, 아욱, 양배추, 배추, 당근)을 이용하여 금속산화물 나노입자(CuO, NiO, Fe₂O₃, Co₃O₄, TiO₂, ZnO)들이 씨앗발아와 발아지수에 미치는 영향을 조사하였다. CuO, ZnO, NiO 나노입자는 씨앗 활성에 뚜렷한 독성 영향을 나타내었으며, 나노입자종류에 따라 상이한 민감도를 나타내었다. 각 나노입자에 대한 독성순서(EC₅₀ 범위)는 다음과 같다: CuO 6~27 mg/L > ZnO 16~86 mg/L > NiO 48~112 mg/L. 나머지 조사 대상 나노입자인 Co₃O₄, TiO₂, Fe₂O₃은 최대 1,000 mg/L 높은 농도 노출에도 뚜렷한 영향을 나타내지 않았다. 씨앗별 상이한 민감도를 나타내었으며, 가장 민감한 종인 아욱의 씨앗발아 EC₅₀은 CuO 5.5 mg/L ZnO 16.4 mg/L, NiO 53.4 mg/L로 조사되었다. 씨앗별 나노입자에 대한 독성 영향은 CuO > ZnO > NiO > Fe₂O₃ ≈ Co₃O₄ ≈ TiO₂ 나타났으나, 당근씨앗은 NiO [EC₅₀ 80.4(71.41~90.54) mg/L]와 ZnO [EC₅₀ 85.8(69.31~106.29) mg/L]가 유사한 독성을 나타내었다.

• 한국진공학회지
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• 제9권1호
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• pp.24-29
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• 2000

MgO thin films were deposited on soda lime glass substrates by rf magnetron sputtering using a MgO target at various oxygen flow ratios in order to probe the relationship between MgO film properties and discharge characteristics. MgO films have a tendency to form microstructures with a preferred growth orientation of (200) with increasing oxygen flo ration up to 0.1 $O_2$/(Ar+$O_2$). MgO film obtained at 0.1[$O_2$/(Ar+$O_2$)] was found to be fully stoichiometric. The stoichiometric MgO film was observed to have relatively very clean surface and grains of large size and contain almost no hydroxyl group. The AC PDP with fully stoichiometric MgO film showed lower firing and sustain voltages than those with magnesium-rich or oxygen-rich MgO films, being largely attributed to the larger grain size and the minimized hydroxyl group.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.408-408
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• 2010

현재 AC-PDP에서는 이온 sputtering 으로부터 유전층을 보호하기 위하여 유전체 위에 MgO 박막을 증착하여 사용하고 있으며 MgO 박막은 높은 2차 전자 방출 계수와 내 sputtering 특성을 가지고 있다. MgO 박막은 증착 조건에 따라 각각 다른 방전특성을 가지는 것으로 널리 알려져 있어 본 실험에서는 MgO 박막을 증착하는데 사용하는 pellet의 크기를 변화시켜가면서 MgO박막을 증착하여 그에 따른 방전특성을 고찰해 보았다. 각각의 MgO pellet의 크기는 1.5, 0.5 mm 와 60 um이며, 기존의 MgO pellet의 크기는 6 mm 이다. MgO pellet 을 E-beam evaporation 방법으로 증착하여 최적화된 test panel을 제작하였다. 제작된 test panel의 방전 전압 특성을 측정하였으며, 실험 결과 AC-PDP의 면방전 구동 시 MgO pellet의 크기가 작아짐에 따라 방전 개시 전압과 방전 유지 전압이 약 11 %, 16 % 감소하였다. 그러나 MgO pellet의 크기가 60 um 경우의 방전 개시 전압은 MgO pellet의 크기가 0.5 경우의 방전 개시 전압과 차이가 없었다. 이는 MgO 증착시에 사용되는 pellet은 적정의 크기가 있는 것으로 보인다.

• Progress in Superconductivity
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• 제3권2호
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• pp.188-192
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• 2002

To introduce flux pinning center in HTS-BSCCO system, nano-size MgO particles were uniformly distributed within the Bi-2223 grain by partial hydration of MgO. The existing method MgO doped Bi-2223 used nato-size MgO powders, which resulted in agglomeration during mixing or grain growth during heat-treatment due to the high surface energy of the fine particles. By hydration of the MgO surface, the agglomeration of the MgO powders was avoided and the size of remaining MgO core was controlled by changing hydration medium and time. The thin film obtained by spin coating of (Bi_$1.8/Pb_{0.4}$)$Sr_2$$_{Ca}$$2.2/Cu_3$ $O_{y}$ nitrate solution mixed with hydrated MgO showed the even distribution of nano-size MgO particles in the Bi-2212 grains.s.s.