• 한국안광학회지
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• 제16권4호
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• pp.357-362
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• 2011

목적: $Ti_3O_5$와 $SiO_2$를 이용하여 중심파장이 500 nm에서 반치폭이 약 12 nm이고 투과율이 99%인 협대역 칼라투과필터를 제작하고, 이 칼라필터의 박막 특성을 연구하고자 한다. 방법: 두께 800 nm인 $Ti_3O_5$박막과 $SiO_2$박막의 투과율로부터 박막의 광학상수 n(굴절률)과 k(소멸계수)를 구하였고, Essential Macleod program을 이용하여 중심파장이 500 nm에서 반치폭이 약 12 nm이고 투과율이 99%인 협대역 칼라투과필터의 필터층과 AR 코팅층을 설계하였다. 또 한 electron beam evaporation 장치를 이용하여 $Ti_3O_5/SiO_2$ 다층막 칼라필터을 만든 후, 분광광도계를 이용하여 투과율을 측정하였고, SEM 사진에 의한 칼라필터의 단면으로부터 칼라필터의 박막두께와 층수를 알 수 있었고, XPS분석으로부터 박막 성분을 분석하였다. 결과: 칼라필터의 AR 코팅층의 최적조건은 6층으로 [air$|SiO_2(90)|Ti_3O_5(36)|SiO_2(5)|Ti_3O_5(73)|SiO_2(30)|Ti_3O_5(15)|$ glass]이며, 반치폭이 12 nm인 칼라필터의 필터층의 최적조건은 41층으로 [air$|SiO_2(20)|Ti_3O_5(64)|SiO_2(102)|Ti_3O_5(66)|SiO_2(112)|Ti_3O_5(74)|SiO_2(120)|Ti_3O_5(68)|SiO_2(123)|Ti_3O_5(80)|SiO_2(109)|Ti_3O_5(70)|SiO_2(105)|Ti_3O_5(62)|SiO_2(99)|Ti_3O_5(63)|SiO_2(98)|Ti_3O_5(51)|SiO_2(60)|Ti_3O_5(42)|SiO_2(113)|Ti_3O_5(88)|SiO_2(116)|Ti_3O_5(68)|SiO_2(89)|Ti_3O_5(49)|SiO_2(77)|Ti_3O_5(48)|SiO_2(84)|Ti_3O_5(51)|SiO_2(85)|Ti_3O_5(48)|SiO_2(59)|Ti_3O_5(34)|SiO_2(71)|Ti_3O_5(44)|SiO_2(65)|Ti_3O_5(45)|SiO_2(81)|Ti_3O_5(52)|SiO_2(88)|$ glass] 이었다. 위의 데이터를 이용하여 제작한 칼라필터는 SEM 사진에 의해 41층으로 확인되었으며, XPS 분석에 의해 $SiO_2$층이 맨 위층이며 $Ti_3O_5$층과 교번인 다층막으로 형성돼 있으며, $Ti_3O_5$박막 형성 시 TiO2 박막과 $Ti_3O_5$박막이 섞여 형성됨을 알 수 있었다. 결론: 41층의 $Ti_3O_5/SiO_2$ 다층박막을 이용하여 12 nm 반치폭을 갖으며 500 nm 중심파장에서 투과율은 99%인 협대역 칼라투과필터를 제작하였으며, 이 칼라필터는 $Ti_3O_5$박막 형성 시 TiO2 박막과 $Ti_3O_5$박막이 섞여 형성됨을 알 수 있었다.

• 한국세라믹학회지
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• 제26권3호
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• pp.423-437
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• 1989

Al2O3/ZrO2 composites were prepared by precipitation method using Al2(SO4)3.18H2O, ZrOCl2.8H2O and YCl3.6H2O as starting materials and NH4OH as a precipitation agent. Al2O3/ZrO2 composites(series A) were prepared by mixing Al2O3 powder obtained by single precipitation method with ZrO2(＋3m/o Y2O3) powder obtained by co-predipitation method. Al2O3/ZrO2 composites (series B) were prepared by co-precipitation method using the three starting materials. In all cases, the composition was controlled as Al2O3-15v/o ZrO2(＋3m/o Y2O3). The composites of series A showed higher final relative densities than those of series B and tetagonal ZrO2 in all cases was retained to about 95% at room temperature. ZrO2 particles were coalesced more rapidly in grain boundary of Al2O3 than within Al2O3 grain. ZrO2 particles were located at 3-and 4-grain junction of Al2O3 and limited the grain growth of Al2O3. It was observed that MgO contributed to densification of Al2O3 but limited grain growth of Al2O3 by MgO was not remarkable. In all Al2O3/ZrO2 composites, exaggerated grain growth of Al2O3 was not observed and Al2O3/ZrO2 composites were found to have homogeneous microstructures.

• 한국세라믹학회지
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• 제24권1호
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• pp.33-40
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• 1987

The investigation includes phase equilibria of Al2O3-HfO2 Cr2O3-ZrO2, Cr2O3-HfO2, Al2O3-Cr2O3-ZrO2, Al2O3-Cr2O3-HfO2, Al2O3-ZrO2-HfO2, Cr2O3-ZrO2-HfO2, Al2O3-Cr2O3-ZrO2-HfO2. In the systems the solubility near the end members has been studied at 1500$^{\circ}C$ and 1600$^{\circ}C$, respectively. Selective Compositions were investigated in the area of the guarternary system where the phae relation was examined.

• 한국세라믹학회지
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• 제26권2호
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• pp.210-220
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• 1989

The properties of the powder of Al2O3-15v/o ZrO2(＋3m/o Y2O3) system prepared by co-precipitation method at the pH values of 7, 9, 10 and 11 were investigated. Al2(SO4)3.18H2O, ZrOCl2.8H2O and YCl3.6H2O were used as starting materials and NH4OH as a precipitation agent. Zirconium hydroxide decreased the specific surface area of aluminum hydroxide of AlOOH type, while increased the specific surface area of aluminum hydroxide of Al(OH)3 type, and formed co-network structure of Al-O-Zr type with the aluminum hydroxides. The rate of transition to $\alpha$-Al2O3 from co-precipitated materials occurred in the order of 7≒10, 9 and 11 of pH values. Al2O3 and ZrO2 interacted to bring about coupled grain growth, and the growth of ZrO2 crystallite size rapidly occurred within $\theta$-Al2O3 matrix. Segregation did not occur in the system Al2O3-15v/o ZrO2(＋3m/o Y2O3) and Y2O3 acted as a stabilizer to ZrO2. The lattice strain of tetragonal ZrO2 was increased by the constraint effect of Al2O3 matrix.

• 한국세라믹학회지
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• 제27권8호
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• pp.991-1003
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• 1990

A precipitation method, one of the most effective liquid phase reaction methods, was adopted in order to prepare high-tech Al2O3/ZrO2 composite ceramics. Al2(SO4)3.18H2O, ZrOCl2.8H2O and YCl3.6H2O were used as starting materials and NH4OH as a precipitation agent, various types of metal hydroxides were obtained by single precipitation(series A) and co-precipitation(series B) method at the pH condition between 7 and 11. Fine Al2O3-ZrO2 powders were prepared at optimum calcination condition and the effects of ZrO2 on microstructures and mechanical properties of Al2O3 were investigated. The composition of Al2O3/ZrO2 composites wax fixed as Al2O3-15 v/o ZrO2(＋3m/o Y2O3). ZrO2 limited the grain growth of Al2O3 and increased grain size homogeneity of Al2O3 more effectively than MgO.Flexural strength values in Al2O3 and Al2O3/ZrO2 composites were 340-430 MPa and 540-820 MPa, respectively, and the effect of strength improvement showed 20-50% by adding ZrO2 to Al2O3. Fracture toughness of Al2O3/ZrO2 composites was improved by stress-induced phase transformation of tetragonal ZrO2 and toughening effect by microcrack was not observed. Also, ZrO2 particles located at Al2O3 grain junction contributed to toughening, while spherical ZrO2 particles located within Al2O3 grain did not contribute to toughening. Weibull moduli of Al2O3 ceramics and Al2O3/ZrO2 composites of series A and series B were 4.34, 5.17 and 9.06, respectively. Above 0.5 of failure probability, strength values in Al2O3 ceramics and Al2O3/ZrO3 composites of series A and series B were above 400 MPa, 700 MPa and 650 MPa, respectively.

• 한국재료학회지
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• 제1권2호
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• pp.65-70
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• 1991

$ZnO-Bi_2O_3-CoO-Sb_2O_3$와 $ZnO-Bi_2O_3-CoO-Sb_2O_3-Cr_2O_3$계에서 미세구조 변화 및 전기적 특성에 미치는 개재물의 영향을 조사하였다. 소결동안에 ZnO입자 성장은 스피넬 입자들에 의해 제어되었으며, 스피넬 입자들의 양의 증가에 의해 입자성장은 감소하였다. $Cr_2O_3(0.5mol\%)$의 첨가는 비직선성지수에는 큰 영향을 미치지 못하였으며 임계전압(breakdown voltage)을 증가시켰다. 계산에 의해 구한 장벽전압은 $ZnO-Bi_2O_3-CoO-Sb_2O_3$와 $ZnO-Bi_2O_3-CoO-Sb_2O_3-Cr_2O_3$ 계에서 각각 3.1V와 2.9V이었다.

• 한국세라믹학회지
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• 제44권11호
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• pp.639-644
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• 2007

Spinel pigments, developing black color in high temperature glazes at oxidation or reduction atmosphere, without CoO because of its high price were synthesized by solid solution method. Ten mixed compositions consisted of NiO, MnO, $Fe_2O_3 and $Mn_2O_3$ were fired at $1250^{\circ}C$ for 1h. The resulting pigments were characterized by using XRD, FT-IR, SEM and UV-vis spectrometer. Structure of the pigments are spinel and particles' shape are spherical or cubic. Glazed tiles containing 5 wt% pigments were fired at $1260^{\circ}C$ and $1240^{\circ}C$ in reduction atmosphere. Color in glazes were analyzed by UV-vis spectrometer. Colors of NiO 0.875 MnO $0.125{\cdot}Fe_2O_3$ $0.4875{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.0125 mole% and NiO 0.875 MnO $0.125{\cdot}Fe_2O_3$ $0.3875{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.1125 mole% in lime glaze showed black in oxidation, in reduction NiO 0.875 MnO $0.125{\cdot}Fe_2O_3$ $0.4875{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.0125 mole% and NiO 0.875 MnO $0.125{\cdot}Fe_2O_3$ $0.4375{\cdot}Cr_2O_3$ $0.55{\cdot}Mn_2O_3$ 0.0125 mole% showed black. In case of lime-barium glaze, NiO 0.875 MnO $0.125{\cdot}Fe_2O_3$ $0.3875{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.1125 mole%, NiO 0.975 MnO $0.075{\cdot}Fe_2O_3$ $0.4375{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.0625 mole% and NiO 0.925 MnO $0.075{\cdot}Fe_2O_3$ $0.4375{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.0625 mole% showed black color in oxidation and NiO 0.875 MnO $0.125{\cdot}Fe_2O_3$ $0.3875{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.1125 mole%, NiO 0.925 MnO $0.075{\cdot}Fe_2O_3$ $0.4375{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.0625 mole% and NiO 0.725 MnO $0.275{\cdot}Fe_2O_3$ $0.4375{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.0625 mole% showed black one in reduction.

• Korean Chemical Engineering Research
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• 제45권6호
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• pp.648-655
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• 2007

UV/H_2O_2$, $O_3$, $O_3/H_2O_2$, $UV/H_2O_2/O_3$ 공정을 이용한 테레프탈산 제조공정 폐수의 COD 및 색도제거 연구를 수행하였다. UV/H_2O_2$, $O_3$, $O_3/H_2O_2$, $UV/H_2O_2/O_3$ 공정에서의 COD 제거율은 각각 10, 48, 56, 63%, 색도 제거율은 $UV/H_2O_2$ 공정이 80%, $O_3$, $O_3/H_2O_2$, $UV/H_2O_2/O_3$ 공정은 모두 99% 이상 효과적으로 제거되는 것으로 나타났다. COD 및 색도 제거율이 가장 우수한 $UV/H_2O_2/O_3$ 공정에서 테레프탈산 제조공정 폐수의 주요 유기물 성분인 테레프탈산, 이소프탈산 그리고 벤조산 성분은 120분 이내에 모두 99% 이상 제거되었다. 또한 $UV/H_2O_2$, $O_3/H_2O_2$, $UV/H_2O_2/O_3$ 공정에서의 최적 $H_2O_2$ 주입농도는 각각 0.5M, 25 mM 그리고 5 mM로 나타나, UV와 $H_2O_2$를 오존산화 공정에 조합함으로써 유기물 제거율 향상과 함께 사용된 $H_2O_2$의 저감효과를 동시에 얻을 수 있었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.543-546
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• 2004

The melting temperature and critical temperature(Tc) of $YBa_2Cu_3O_x$ with deferent content impurities of PbO and $BaPbO_3$ were studied. When the PbO was used as addition in $YBa_2Cu_3O_x$, although the melting point could be reduced, the superconductivity(the transition width, ${\Delta}T_c$) became poor. From the XRD pattern of the sintered mixture of $YBa_2Cu_3O_x$ and PbO it was known that there is a reaction between $YBa_2Cu_3O_x$ and PbO, and the product is $BaPbO_3$. In the process of the reaction the superconducting phase of $YBa_2Cu_3O_x$ was decreased and in the sample $BaPbO_3$ became the main phase. Therefore the superconductivity was reduced. $BaPbO_3$ was chosen as the impurity for the comparative study. The single phase BaPbO3 was synthesized by the simple way from both mixtures of $BaPbO_3$ and PbO, $BaPbO_3\;and\;PbO_2$. Deferent contents of $BaPbO_3$(10%, 20%, 30%) were added in the $YBa_2Cu_3O_x$. By the phase analysis in the XRD patterns it was proved that there werenot reactions between $YBa_2Cu_3O_x$ and $BaPbO_3$. When $BaPbO_3$ was used as impurity in $YBa_2Cu_3O_x$ the superconductivity was much better than PbO as impurity in $YBa_2Cu_3O_x$. But the melting point of $YBa_2Cu_3O_x$ with $BaPbO_3$ could not be found when the temperature was lower than $1000^{\circ}C$ in the DTA measurement.

• 대한화학회지
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• 제51권3호
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• pp.240-243
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• 2007

8배위 이트륨(III) 화합물 Y(tpb)3(H2O)2을 합성하였고 X-선 회절법으로 구조를 규명하였다. 이 화합물은 12 면체의 구조를 가지며, 두 면(Y-O2-O1-O5-O6 and Y-O4-O3-O8-O7)사이의 각은 89.59o이다. 또한, O1-O5과 O3-O8 의 거리는 2.965 and 2.995 A이며 O2-O6과 and O4-O7의 거리는 4.256 and 4.403 A이다.