• Transactions on Electrical and Electronic Materials
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• 제10권2호
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• pp.49-52
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• 2009

Barium strontium calcium titanate powders were prepared with the sol-gel method. Ferroelectric $(Ba_{0.54}Sr_{0.36}Ca_{0.1})TiO_3$(BSCT) thick films were fabricated by the screen-printing method on alumina substrate. Then we investigated the structural and dielectric properties of the BSCT thick films at different sintering temperatures. The thermal analysis showed that the BSCT polycrystalline perovskite phase formed at around $660^{\circ}C$. The X-ray diffraction analysis showed a cubic perovskite structure with no second phase present in all of the BSCT thick films. The average grain size and the thickness of the specimens sintered at $1450^{\circ}C$ were about $1.6{\mu}m$ and $45{\mu}m$, respectively. The relative dielectric constant increased and the dielectric loss decreased as the sintering temperature was increased; for BSCT thick films sintered at $1450^{\circ}C$ the values of the dielectric constant and the dielectric loss were 5641 and 0.4%, respectively, at 1 kHz.

• 한국전기전자재료학회논문지
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• 제19권12호
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• pp.1106-1111
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• 2006

To improve warpage, delamination and the chemical reaction between 2 different co-fired materials, the bonding behavior with common glass was studied. As shown in the previous paper, the phenomenon of the infiltration is different with the composition of the glass. In particular, in the case of low temperature melting glass, infiltration is experimented in this study. GA-1 glass is infiltrated among $BaTiO_3$ particles below $800^{\circ}C$ and is made by glass/ceramic composite. Until the laminate is fired under $850^{\circ}C$, provskite phase is observed. Although in the case of GA-12 glass, the temperature of the glass infiltration is lower than it of GA-l glass, the perovskite phase already disappears at $800^{\circ}C$. As a result, GA-1 and GA-12 glasses are infiltrated among particles at low temperature, however, the chemical reactivity of the glass/ceramic and sintering temperature should be considered.

• 한국결정성장학회지
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• 제30권1호
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• pp.17-20
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• 2020

고성능의 산소생성반응(OER)과 수소생성반응(HER) 전기촉매 개발은 수전해 시스템의 상용화에 있어서 매우 중요하게 여겨진다. 특히 HER에 비하여 OER이 상대적으로 높은 과전압을 가지기 때문에, OER의 과전압을 효과적으로 낮추는 촉매를 개발하는 것이 매우 중요하다. 본 연구에서는, 매우 간단한 공정을 통하여 triple perovskite 구조의 Nd_1.5Ba_1.5CoFeMnO_x 전기촉매를 합성하였으며 그 특성을 분석하였다. 합성된 Nd_1.5Ba_1.5CoFeMnO_x는 OER 뿐만 아니라 HER에서도 우수한 특성을 나타내었다. 이러한 결과를 통하여 높은 결정성을 가지는 triple perovskite 구조가 간단한 연소 합성법(combustion synthetic method)을 통하여 합성될 수 있으며 알칼리 전해질 하에서 매우 우수한 촉매특성을 보이는 것을 확인할 수 있었다. 따라서, 높은 OER, HER 특성을 보이는 Nd_1.5Ba_1.5CoFeMnO_x triple perovskite 촉매는 수전해 시스템의 상용화에 큰 기여를 할 수 있을 것으로 판단된다.