• 한국재료학회지
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• 제20권7호
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• pp.370-373
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• 2010

In fabricating plasma display panels, the photolithographic process is used to form patterns of barrier ribs with high accuracy and high aspect ratio. It is important in the photolithographic process to control the refractive index of the photosensitive paste. The composition of this paste for photolithography is based on the $B_2O_3-SiO_2-Al_2O_3$ glass system, including additives of alkali oxides and rare earth oxides. In this work, we investigated the density, structure and refractive index of glasses based on the $B_2O_3-SiO_2-Al_2O_3$ system with the addition of $Li_2O$, $K_2O$, $Na_2O$, CaO, SrO, and MgO. The refractive index of the glasses containing K2O, Na2O and CaO was similar to that of the [BO3] fraction while that of the SrO, MgO and Li2O containing glasses were not correlated with the coordination fraction. The coordination number of the boron atoms was measured by MAS NMR. The refractive index increased with a decrease of molar volume due to the increase in the number of non-bridging oxygen atoms and the polarizability. The lowest refractive index (1.485) in this study was that of the $B_2O_3-SiO_2-Al_2O_3-K_2O$ glass system due to the larger ionic radius of $K^+$. Based on our results, it has been determined that the refractive index of the $B_2O_3-SiO_2-Al_2O_3$ system should be controlled by the addition of alkali oxides and alkali earth oxides for proper formation of the photosensitive paste.

• Current Optics and Photonics
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• 제8권3호
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• pp.230-238
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• 2024

The refractive index is a key material-design parameter, especially for high-refractive-index glasses, which are used for precision optics and devices. Increased demand for high-precision optical lenses produced by the glass-mold-press (GMP) process has spurred extensive studies of proper glass materials. B₂O₃, SiO₂, and multiple heavy-metal oxides such as Ta₂O₅, Nb₂O₅, La₂O₃, and Gd₂O₃ mostly compose the high-refractive-index glasses for GMP. However, due to many oxides including up to 10 components, it is hard to predict the refractivity solely from the composition of the glass. In this study, the refractive index of optical glasses based on the B₂O₃-La₂O₃-Ta₂O₅-SiO₂ system is predicted using machine learning (ML) and compared to experimental data. A dataset comprising up to 271 glasses with 10 components is collected and used for training. Various ML algorithms (linear-regression, Bayesian-ridge-regression, nearest-neighbor, and random-forest models) are employed to train the data. Along with composition, the polarizability and density of the glasses are also considered independent parameters to predict the refractive index. After obtaining the best-fitting model by R² value, the trained model is examined alongside the experimentally obtained refractive indices of B₂O₃-La₂O₃-Ta₂O₅-SiO₂ quaternary glasses.

• 상하수도학회지
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• 제25권1호
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• pp.7-14
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• 2011

This study was motivated by the purpose of improving the O-Index, currently used to quantify water tasty. The authors first develop the M-Index after normalizing Ca, K, and $SiO_{2}$ concentrations in the spring water, in that the concentrations are subject to their log-normal distributions. The M-Index is then compared with the O-Index based on the results of sensory tests, revealing that sensory tests are correlated with the M-Index much more than the O-Index. Furthermore, the developed index is applied to evaluate water sampled from 53 springs in Korea. It is concluded that water, sampled from five most famous springs, has high values in M-Index. In addition, water, collected from springs that are relatively accessible, contains low values, and thus is expected not to tasty good.

• 한국안광학회지
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• 제7권2호
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• pp.27-31
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• 2002

4성분 $Li_2O-B_2O_3-Al_2O_3-SiO_2$ 유리들을 $R({\equiv}Li_2Omole%/B_2O_3mole%)$과 $K({\equiv}(Al_2O_3mole%+SiO_2mole%/B_2O_3mole%)$에 의해 제작하여 유리들의 구조를 굴절률 (refractive index)과 Vicker's 경도(hardness)의 변화를 측정하여 분석하였다. 먼저, 굴절률의 증가는 유리 내부구조의 분극률을 증가시키는 $Li^+$ 양이온 수의 증가에 우선적으로 의존하여 증가하였으며, 적은 양의 리튬 산화물($Li_2O$)이 첨가된 영역에서는 굴절률은 리튬 이온 양에 의존하며, 많은 양의 리튬 산화물이 첨가된 영역에서는 큰 몰 부피를 갖고 하나의 비가교 산소를 갖는 $BO_3{^-}$ 단위들의 형성으로 유리 구조 내의 몰 부피 증가로 유리들의 굴절률의 증가가 둔화되었다. 그리고 알루미늄 산화물($Al_2O_3$)과 규소 산화물($SiO_2$)의 증가에 따라 굴절률의 감소는 $Al_2O_3$와 $SiO_2$에 의해 형성되어진 $AlO_4$ 단위들과 $SiO_4{^-}$ 단위들이 붕소 산화물($B_2O_3$)에 의해 형성되어진 $BO_4$단위들보다 몰 부피의 증가로 감소되어졌다. 또한, 경도의 증가는 유리 망목구조에 형성되어지는 $BO_4$ 단위 수에 의존하였으며, 경도의 감소는 유리 망목구조를 개방화시키는 $BO_3{^-}$ 단위 수에 의존하여 감소함을 알 수 있었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.307-308
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• 2009

We have proposed an index matching film to improve the emitting efficiency of green OLED. Here, SiO2 and TiO2 were selected to coat the green OLED. The structures of index matching film were designed in G1ass/TiO2/SiO2/ITO and SiO2/TiO2/Glass/ITO. Then, these materials were deposited by ion-assisted deposition system. Transmittances of deposited devices were 86.14 and 85.07 %, respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.321-321
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• 2008

To obtaingood resolution in PDP, one of the important factors is to achieve the accuracy of barrier ribs. The photolithographic process can be used to form patterns of barrier rib with high accuracy and a high aspect ratio. The composition for photolithography is based on the $B_2O_3-SiO_2-Al_2O_3$ glass system including additives such as alkali oxides and alkali earth oxides. The refractive index and thermal properties in glass system are changed by amount of alkali oxides and alkali earth oxides. Therefore, it is important that additives are controlled to have proper refractive index and thermal properties. The additives are contributed to non-bridging oxygen within the glass network, causing a change of density. In addition to a change of the structural cross-link density, the refractive index, dielectric and thermal properties glass are correlated with ionic radius and polarizability of cations. In this study, we investigated the refractive index and the thermal properties such as glass transition temperature, glass softening temperature and coefficient of thermal expansion by changing composition in the $B_2O_3-SiO_2-Al_2O_3$ glass system.

• 한국세라믹학회지
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• 제34권7호
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• pp.693-698
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• 1997

The refractive index and dispersion in the (100-x)(0.6CaO.0.4Al2O3).xSiO2(x=0~30) glasses were investigated. As the amount of SiO2 increased, the refractive index decreased. The change of refractive index was attributed to the change of the molar refraction rather than the molar volume. When the amount of SiO2 was smaller than 20 mol%, the average electronic transition energy gaps(E0) and the electronic oscillator strengths(Ed) were about 10.9($\pm$0.1) nd 18($\pm$0.5)eV, respectively. However E0 and Ed of the glass (CAS30) with 30 mol% SiO2 increased to 12.63 and 19.89eV, respectively. The similar results was observed in the variation of Abbe Number. Abbe number of the glass in the range of 0~20 mol% SiO2 was about 46 and that of CAS30 increased to 60. The zero-material dispersion wavelength({{{{ lambda }}0) of pure calcium aluminate glass was 1.8 ${\mu}{\textrm}{m}$. As the amount of SiO2 increased, the zero-material dispersion wavelength shifted to a shorter wavelength. {{{{ lambda }}0 of CAS30 was 1.5 ${\mu}{\textrm}{m}$, that is currently using for the optical telecommunication system.

• 한국진공학회지
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• 제6권S1호
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• pp.75-79
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• 1997

Optical and mechanical characteristics of $TiO-2, ZrO_2 \;and\; SiO_xN_y$ thin films prepared by ion assisted deposition (IAD) were investigated. IAD films were bombarded by Ar or nitrogen ion beam from a Kaufman ion source while they were grown in as e-beam evaporator. The result shows that the Ae IAD increases the refractive index and packing density of $TiO_2 films close to those of the bulk. For $ZrO_2$ films the Ar IAD increases the average refractive index decreases the negative inhomogeneity of refractive index and reverses to the positive inhomogeneity. The optical properties result from improved packing density and denser outer layer next to air The Ar-ion bombardment also induces the changes in microstructure of $ZrO_2$ films such as the preferred (111) orientation of cubic phase increase in compressive stress and reduction of surface roughness. Inhomogeneous refractive index SiOxNy films were also prepared by nitrogen IAD and variable refractive index of $SiO_xN_y$ film was applied to fabricate a rugate filter.

• 한국안광학회지
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• 제8권1호
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• pp.1-5
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• 2003

4성분 $Na_2O-B_2O_3-Al_2O_3-SiO_2$ 유리들을 $R({\equiv}Na_2O\;mole%/B_2O_3\;mole%)$과 $K({\equiv}(Al_2O_3\;mole%+SiO_2\;mole%)/B_2O_3mole%)$에 의해 제작하여 유리들의 구조를 굴절률(refractive index)과 vicker's 경도(hardness)의 변화를 측정하여 분석하였다. 먼저, 굴절률의 증가는 유리 내부구조의 분극률을 증가시키는 $Na^+$ 양이온수의 증가에 우선적으로 의존하여 증가하였다. 적은 양의 소듐 산화물($Na_2O$) 이 첨가된 영역에서 굴절률은 소듐 이온 양에 의존하였으며, 많은 양의 소듐 산화물이 첨가된 영역에서는 큰 몰 부피를 갖고 하나의 비가교 산소를 갖는 $BO_3{^-}$ 단위들의 형성으로 유리 구조 내의몰 부피 증가로 유리들의 굴절률의 증가가 둔화되었다. 그리고 알루미늄 산화물($Al_2O_3$)과 규소 산화물($SiO_2$)의 증가에 따라 굴절률의 감소는 $Al_2O_3$와 $SiO_2$에 의해 형성되어진 $AlO_4$ 단위들과 $SiO_4{^-}$ 단위들이 붕소 산화물($B_2O_3$)에 의해 형성되어진 $BO_4$ 단위들보다 몰 부피의 증가로 감소되어졌다. 또한, 경도의 증가는 유리 망목구조에 형성되어지는 $BO_4$ 단위 수에 의존하였으며, 경도의 감소는 유리 망목구조를 개방화시키는 $BO_3{^-}$ 단위 수에 의존하여 감소함을 알 수 있었다.

• 한국세라믹학회지
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• 제17권4호
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• pp.203-207
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• 1980

The optical absorption of high index glasses of the system TiO2-BaO-B2O3 prepared from the raw materials for an optical waveguide glass has been measured in the near ultraviolet region. The amount of Ti3+ in the glass could be reduced to a level less than 5 ppm by melting a batch added with pure nitric acid, using a fused quartz crucible in an oxygen gas atmosphere. The ultra-pure glass of 10mm thick prepared in such a way did not show any appreciable color even for the one containing 30 mol% TiO2 and having refractive index nD of 1.84 and Abbe's number vD of 28.8. The wavelength of ultraviolet absorptin edge was longer for the glass of higher index and higher dispersdion. The melting of a TiO2 containing glass in a platinum crucible resulted in a coloration of the glass due to the dissolved plutinum from the crucible, which was more intense for the one containing larger amount of TiO2.