• 전자공학회논문지 IE
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• v.43 no.4
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• pp.8-12
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• 2006

In this paper, reflectance and the dielectric characteristics for $P_2O_5$-ZnO-BaO system and $SiO_2-ZnO-B_2O_3$ system have been investigated as a function of contents of $TiO_2$. The reflectance was decreased with increasing the contents of $TiO_2$ contents, and the reflectance of $P_2O_5$-ZnO-BaO system was lowered than that of $SiO_2-ZnO-B_2O_3$ system. The dielectric constant of $P_2O_5$-ZnO-BaO system was higher than $SiO_2-ZnO-B_2O_3$ system, and the dielectric constant in the both system was increased with increasing of $TiO_2$ contents. This can explained as the space charge effects. These results are could be applied to the lower dielectrics layer of PDP required high reflective ratio and breakdown strength.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2053-2056
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• 2000

The experiment on characteristic of $NO_x$ removal for $BaTiO_3$-sludge hybrid packed bed type reactor was conducted. Gas flow rate was 5(${\ell}/min$) and NO concentration was 50, 100 and 150(ppm). The effect on volume percent of $BaTiO_3$ to sludge was investigated, sludge pellets was added to $BaTiO_3$ pellets to increase $NO_x$ removal rate. In the result, when sludge pellets was added, NO removal rate of $BaTiO_3$ - sludge hybrid type was increased from 90.6% to 95%. However $NO_2$ decreased from 88ppm to 10ppm. $O_3$ decreased from 77ppm to 2ppm. $NO_x$ removal rate was increased to 74%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.209-209
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• 2010

Multiferroic properties of $BaTiO_3-CuFe_2O_4$ thin films grown on highly-textured Pt(111)/$TiO_2/SiO_2$/Si(100) substrates were studied. $CuFe_2O_4$ ceramic target was synthesized by mixing oxide powders of CuO, $Fe_2O_03$, $BaTiO_3$ ceramic target was also prepared separately. The film structure was of bi-layer type, where $BaTiO_3$ layer lies underneath of $CuFe_2O_4$ layer, where both layers were grown by pulsed laser deposition technique. We will report the ferroelectric and magnetic properties of $BaTiO_3-CuFe_2O_4$ bi-layer films in some detail.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2013-2015
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• 2005

In this paper, Effect of $BaSrTiO_3/Li_2CO_3$ on low temperature sintering and dielectric property of thick films has been investigated for variable capacitor on high frequency. The thick films were fabricated by the tape casting and then the structural and dielectric properties as a function of an addition composition ratio and sintering temperature were studied. For the thick film sintered at $1050^{\circ}C$, it was densified to 96% of $BaSrTiO_3$ theoretical density by the addition of 10 $wt{\cdot}%$ $BaSrTiO_3/Li_2CO_3$. Dielectric constant increased and Curie temperature lowered with the increased of $BaSrTiO_3/Li_2CO_3$ content, which probably can be explained by the substitution of $Ba^{3+},Li^{1+}$ on $RaTiO_3$ lattice. The tunability and dielectric loss of the $BaSrTiO_3/Li_2CO_3$ thick film, sintered at $1350^{\circ}C$, were about 26% and 0.234 at $10{\sim}15MHz$, respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.656-656
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• 2013

Multi-layer ceramic capacitor (MLCC)는 '전자산업의 쌀'이라고 일컬어 질만큼, 전자부품내에서 매우 중요하고 핵심적인 역할을 하며, 그 응용분야 또한 매우 광범위하다. 이러한 MLCC는 그 사용처에 따라, 초고용량 MLCC, 고전압용 MLCC, 저가제품용 MLCC, 그리고 고용량용 MLCC 등등으로 나뉘어진다. 이 중 최근 각광 받고 있는 스마트폰, 태플릿PC 등의 전자제품군에 사용되는 초고용량 MLCC의 경우, 높은 유전상수 값을 지닌 BaTiO3 기반의 물질이 일반적으로 사용되어지고 있으며, 또한 더 높은 용량(capacitance)을 얻기 위하여 해마다 유전체층의 두께가 점점 줄어들고 있고, 이러한 얇은 유전체층을 만들어 내기위해 유전체층의 결정립 크기도 수 마이크로미터에서 수백, 수십 나노미터 사이즈로 점점 작아지고 있는 상황이다. 하지만 점점 줄어들고 있는 유전체층의 두께와 결정립 크기의 추세와는 상관없이, 전기회로에서 요구되는 인가전압은 줄어들지 않고 일정하게 유지되고 있기 때문에, 유전체층의 내전압 특성은 전자제품의 높은 신뢰성을 위해서 날이 갈수록 중요시 되고 있다. 특히, 수백 나노미터 이하의 결정립 크기를 갖는 BaTiO3 유전체층의 내전압 특성은, 다양한 내전압 특성 메커니즘이 연구되어진 수 마이크로미터 대역의 결정립 크기를 갖는 BaTiO3 유전체층과는 다르게, MLCC 제조공정상의 한계와 BaTiO3의 결정립 성장이라는 어려움 때문에, 그 연구가 전무하다 할 수 있다. 따라서 본 연구에서는 수십 나노미터 결정립 크기를 갖는 BaTiO3 막을 만들어낼 수 있는 에어로졸 데포지션 공정을 이용하여 수십 나노미터 결정립 크기를 갖는 BaTiO3 막을 제조 하였으며, 이 막을 다양한 온도 조건에서 후속 열처리를 통한 결정립 성장을 통해 수십에서 수백 나노미터의 다양한 결정립 크기를 갖는 BaTiO3 막의 내전압 특성을 분석하였다.

• Journal of the Korean Ceramic Society
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• v.35 no.8
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• pp.857-863
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• 1998

The BaTiO3 powders extensively used as MLCC (Multilayer ceramic capacitor) in electronic ceramic in-dustry were synthesized by GNP (Glycine-Nitrate process) The powders were prepared using carbonate and alkoxide as starting materials and nitric acid was used as a solvent for starting materials as well as an oxidant for combustion. The BaTiO3 powders were synthesized using different amounts of glycine as a fuel for combustion. The characteristics of synthesized powders were examined with helium pycnometer X-ray diffraction(XRD) Brunauer-Emmett-Teller with N2 adsorption and scanning electron microscopy(SEM). It was found that single phase BaTiO3 could be formed when the as-synthesized powders were heat-treated at 100$0^{\circ}C$ When the glycine/cation molar ratio was 1,2 specific surface area was 24m2/g

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.12
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• pp.852-856
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• 2014

$BaTiO_3$ nano powder can be synthesized by hydrate salt method at $120^{\circ}C$ in air. Decreasing the thickness of thick film, the nano dielectric particle is needed in electronic ceramics. However, the synthesis of $BaTiO_3$ nano particle at low temperature in air and their mechanism were not reported enough. And ultrasonic treatment can be tried because of low temperature process in air. Therefore, in this study, the $BaTiO_3$ nano powder was synthesised with the synthesis time and ultrasonic treatment at $120^{\circ}C$ in air. In the synthesis process, the effects of process were evaluated. From the experimental observation, the synthesis mechanism was proposed. The homogeneous $BaTiO_3$ particle was synthesised by KOH salt solution at $120^{\circ}C$ for 1hour. It was conformed that the ultrasonic treatment effected on the increase of synthesis rate. After cutting the salt powder using FIB, $BaTiO_3$ nano particles observed homogeneously in the cross-section of the salt particle.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2002.11a
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• pp.165-169
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• 2002

BaTiO$_3$ 분말을 Ba(OH)$_2$ㆍ8$H_2O$와 아나타제형의 TiO$_2$ㆍ$\chi$$H_2O$를 이용하여 광화제 첨가 없이 열수처리에 의한 탈수(dehydration) 및 재결정화(recrystallization) 과정을 통한 수열합성법에 의해 제조하였다. Autoclave 반응기를 이용한 실험의 경우, BaTiO$_3$ 분말을 생성하기 위한 최적 반응온도 및 시간은 각각 21$0^{\circ}C$, 4시간으로 확인되었으며, 이 때 생성된 BaTiO$_3$ 분말의 크기는 0.1~0.2$mu extrm{m}$로 입도분포가 양호하였다. 그리고, 바륨과 티타늄의 농도비가 증가됨에 따라 결정화도(tetragonality)가 증가하는 경향을 나타내고 있다. 이는 반응하지 않고 남아 있는 바륨의 영향으로 생각되며, 이는 반응물의 pH와도 관련이 있다. 또한, 반응온도 및 시간도 결정화도에 커다란 영향을 미치는 변수로 주로 반응온도 및 시간이 증가함에 따라 결정화도도 함께 증가하는 추세를 나타내고 있다.

• Journal of the Korean Ceramic Society
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• v.25 no.3
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• pp.293-299
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• 1988

The effects of flux KCl and dopants, La2O3 and Ta2O5, on the PTCR characteristics in molten salt synthesized BaTiO3 have been studied. The resistivity of BaTiO3 at room temperature decreases with increasing amount of dopant La2O3 up to 0.2 atom%, and then increases with La2O3 content. In case of dopant Ta2O5, it increases with increasing amount ofthe dopant. These results could be explained by observation of the microstructure and defect equation. From the results of complex impedance-frequency characteristics, the grain resistances are almost same but the resistances at the grain boundary are quite different.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.693-696
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• 2001

The (Ba$_{0.3}$Bi$_{0.3}$Sr$_{0.4}$)TiO$_3$[BBST] ceramics were prepared by conventional mixed oxide method. The structural properties of the BBST ceramics with sintering temperature were investigated by XRD, SEM, EDS. In the case of BBST ceramics sintered at 1150~135$0^{\circ}C$, the $Ba_{0.5}$Sr$_{0.5}$TiO$_3$and SrBi$_4$Ti$_4$O$_{15}$ phase were coexisted. The 2$\theta$ value of the BST (110) peaks were shifted to the lower degree at the sintering temperature of 130$0^{\circ}C$ and 135$0^{\circ}C$. The grains of the BBST ceramics sintered at 130$0^{\circ}C$ and 135$0^{\circ}C$ were not appeared. Increasing the sintering temperature, the densities of the BBST ceramics were increased. In the BBST ceramics sintered at 130$0^{\circ}C$ and 135$0^{\circ}C$, the mole ratio of Bi was decreased.d.ed.d.d.d.