• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.271-271
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• 2007

LTCC 소재는 glass/ceramic composite로 구성된다. LTCC 소재에 embedding 되는 고유전율 소재 또한 이와 같은 소재설계를 통하여 무수축 접합이 가능할 것으로 판단된다. 그러나 이에 대한 연구결과가 보고된바 없고 몇몇 $Al_2O_3$의 infiltration에 대한 무수축 소성 관련 선행 연구를 바탕으로 고유전율 소재인 $BaTiO_3$의 무수축 소성이 연구되는 것이 필요한 시점이다. 따라서 본 연구는 저온에서의 glass infiltration에 의한 무수축 $BaTiO_3$ layer의 저온소성특성 및 유전특성을 평가하였다. 실험결과 $785^{\circ}C$에서 glass의 충분한 침투가 확인되며 결정구조에서는 glass/$BaTiO_3$ composite이 형성되었다. 무수축 접합 layer의 소성조건과 glass 두께 변화에 따른 유전특성 및 layer의 결정구조를 비교평가 하였다.

• Korean Journal of Materials Research
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• v.11 no.1
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• pp.44-47
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• 2001

Effects of $Er_2O_3$ addition on the dielectric properties of non-reducible $BaTi_3$-based X7R dielectrics with Ni electrode have been studied in reducing atmosphere. X7R with moderate temperature-dependence was developed after addition of $Er_2O_3$ with $MnO_2-MgO$; room-temperature dielectric constant and dissipation factor were >2900 and < 1.0%, respectively. The addition of $Er_2O_3$ greater than 3.0 mol% improved the temperature dependence of dielectric properties, but a significant decrease of the dielectric constant at room-temperature was observed. The TCC curves rebated clockwise with increasing MnO$_2$ content at a given additive system, 1.5 mol% $Er_2O_3$ and 2.0 mol% MgO.

• Proceedings of the Materials Research Society of Korea Conference
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• 1993.11a
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• pp.114-114
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• 1993

• Journal of the Korean Ceramic Society
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• v.12 no.2
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• pp.10-14
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• 1975

Bodies whose compositions are in the ternary system BaCO3-TiO2-SnO2 containing from 5 to 90 mol % stannic oxide were prepared to improve the thermal characteristics of barium titanate dielectrics. Bodies having dielectric constant (K) of 2100 at 1 KHz, low negative temperature coefficients of 1500ppm up to about 9$0^{\circ}C$, Curie Temperature of 2$0^{\circ}C$, and dissipation factor of 0.2-0.4% were obtained with addition of 15 mole % stannic oxide.

• Journal of the Korean Ceramic Society
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• v.25 no.4
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• pp.315-320
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• 1988

The Nb doped BaTiO3 was synthesized by coprecipitation method using H2O2 media in region from pH 8 to pH 11. The powder prepared by using this method was crystallized at about 20$0^{\circ}C$ and average particle size was controlled by heat treatment. Because of preparation having fine particle and relatively narrow particle size distribution, high performance PTC device was made of these precipitated powders.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.284-284
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• 2010

YBCO ceramic specimens were fabricated by added $BaTiO_3$ as donors and sintered $950^{\circ}C$/24hrs. Average grain size decreased with increased in added $BaTiO_3$. Affect to grain growth. XRD result, peak strength was lowed then crystallization not well all specimens. All specimens critical temperature about 90k.

• Journal of the Korean Ceramic Society
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• v.41 no.6
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• pp.444-449
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• 2004

The microwave dielectric properties of low temperature sintered BaO-Nd$_2$O$_3$-TiO$_2$ (here after BNT) with a Pb-based glass-ceramics were studied in order to investigate their applicability to Low Temperature Co-fired Ceramics (LTCC) for fabrication of multilayered Radio Frequency (RF) passive components module. The BNT ceramics, with 5∼30 wt% of PbO-TiO$_2$-A1$_2$O$_3$-SiO$_2$ based glass-ceramics, were sintered at 105$0^{\circ}C$, which is lower than 130$0^{\circ}C$, sintering temperature of pure BNT ceramics. With increasing the amount of the glass-ceramics, sintering rate of the ceramics become activated due to the softening of glass, resulting in low-temperature densification. BaO-Nd$_2$O$_3$-TiO$_2$ microwave ceramics with 20 wt% glass-ceramics exhibit sintered relative densities over 95% and dielectric constant of 72, quality factor of 1500, and temperature coefficient of frequency of +22 ppm/$^{\circ}C$. This enhanced dielectric properties are attributed to mainly the presence of crystalline phases PbTiO$_3$ within the Pb-based glass.

• Journal of the Korean Society of Safety
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• v.20 no.4 s.72
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• pp.29-33
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• 2005

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 $TiO_2$ 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 be explained as the space charge effects. These results are could be applied to the under plate dielectrics of PDP required high reflective ratio and breakdown strength.

• Journal of Magnetics
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• v.20 no.4
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• pp.353-359
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• 2015

Dielectric properties of $xBaTiO_3-(1-x)CoFe_2O_4$ composite materials have been investigated. Dielectric properties of $BaTiO_3$, $CoFe_2O_4$ and $0.5BaTiO_3-0.5CoFe_2O_4$ samples show frequency dependence, which is classified as relaxor behavior with different relaxing degree. The relaxor behaviors were described using the modified Curier-Weiss and Vogel-Fulcher laws. Among three above samples, the $BaTiO_3$ sample has highest relaxing degree. Photoluminescence spectral indicated defects, which might in turn control relaxing degree.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.55-56
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• 2006

In this paper, we first applied the chemical mechanical polishing (CMP) process to the planarization of ferroelectric film in order to obtain a good planarity of electrode/ferroelectric film interface. BST ($Ba_{0.6}Sr_{0.4}TiO_3$), PZT ($Pb_{1.1}(Zr_{0.52}TiO_{0.48})O_3$) and BTO ($BaTiO_3$) ferroelectric film are fabricated by the sol-gel method. And then, we compared the structural characteristics before and after CMP process of BST, PZT, BTO films. Their dependence on slurry composition was also investigated. We expect that our results will be useful promise of global planarization for ferroelectric random access memories (FRAM) application in the near future.