• 한국전기전자재료학회논문지
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• 제17권2호
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• pp.178-183
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• 2004

PBT thin film was known to be a representative for the FeRAM devices because of its good ferroelectric proporties and the ease in fabricating the thin film. However, there have been several problems such as polarization fatigue and leakage current in memory devices with a PZT thin film. In this study, Sm-dolled PZT thin films were fabricated by the so1-gel method, and their ferroelectric and dielectric proportrics were compared as a function of Sm content. We investigated the effect of the Sm dopant on structural and electrical properties of PZT film. Sm-doped PZT thin films on the Pt/Ti/SiO$_2$/Si substrates have been prepared by a sol-gel method. The remanent polarization and coercive field decreased with increasing the concentration of Sm. The dielectric constant and dielectric loss decreased with Increasing Sm content. Sm-doped PZT thin films showed improved fatigue characteristics compared to the undoped PZT thin film.

• 분석과학
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• 제14권4호
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• pp.291-299
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• 2001

사용후핵연료내 핵분열생성물중 Sm 동위원소 정량을 위한 분리 및 정제에 관한 연구를 수행하였다. 일차적으로 핵분열생성물 대신 여러 비방사성 금속이온(Cs, Ba, Gd, Eu, Sm 및 Nd)들로 구성된 모의용액을 시료로 사용하였다. Sm은 AG $1{\times}8$ 음이온교환수지관에서 1 M $HNO_3$/90% MeOH 용액으로 세척 후 0.5 M $HNO_3$/80% MeOH 용액으로 용리하였다. 용출액에 함유되어 있는 미량의 Ba을 제거하기 위하여 0.2 M alpha-hydroxyisobutyric acid 용액(pH 4.5-4.6)으로 전처리한 AG $50W{\times}8$ 양이온교환수지관에서 정제하였으며, 순수한 Sm을 90% 이상 분리, 회수할 수 있었다. 실제 PWR 사용후핵연료에 함유되어 있는 Sm의 분리 및 정제에 적용하여 용출액을 질량분석한 결과 Gd, Eu, Pm, Nd 및 BaO에 의한 동중원소 영향이 나타나지 않았다. $^{154}Sm$ 스파이크를 이용한 동위원소희석 질량분석법으로 사용후핵연료 중의 Sm 및 각각의 성분 동위원소($^{147}Sm$, $^{148}Sm$, $^{149}Sm$, $^{150}Sm$, $^{151}Sm$, $^{152}Sm$ and $^{154}Sm$)들을 정량하였다.

• 한국결정성장학회지
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• 제20권2호
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• pp.69-73
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• 2010

정전분무증착 기술에 의해 증착된 고체산화물 연료전지(SOFC) 양극재료인 SSC 양극막의 미세구조적 변화에 대해 연구하였다. Samarium chloride hexahydrate$(SmCl_3{\cdot}6H_2O)$, strontium chloride hexahydrate$(Co(No_3)_2{\cdot}6H_2O)$, cobalt nitrate hexahydrate$(Co(No_3)_2{\cdot}6H_2O)$의 출발 물질과 용매로써 메탄올이 전구체 용액을 제조하는데 사용되었다. SOFC의 양극을 위해 적합한 다공성의 SSC 막을 제조하였으며, 그 미세구조가 증착시간, 기판온도, 인가전압 등과 같은 공정변수들에 의존한다는 것을 관찰하였다. 주사전자현미경과 X-ray 회절 패턴이 미세구조와 결정성 분석을 위해 사용되었다. 본 연구를 통해, ESD 기술이 요구하는 상의 합성과 다공성의 미세구조를 갖는 SOFC의 양극막을 제조하는데 효과적인 방법임을 입증하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1689-1691
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• 1999

The conduction characteristics of $Pr_6O_{11}$-based ZnO varistor were investigated. ZnO-$Pr_6O_{11}$-CoO-$Sm_2O_3$-based ZnO varistor were sintered at $1300^{\circ}C$ and $1350^{\circ}C$ in the addition range $0.0\sim2.0mol%$ $Sm_2O_3$, respectively. ZnO varistors which are added with 1.0mol% at each temperature exhibited best excellent conduction characteristics, namely the nonlinear exponent was 42.05 at $1300^{\circ}C$, 36.79 at $1350^{\circ}C$ and leakage current was $9.16{\mu}A$ at $1300^{\circ}C$, $11.7{\mu}A$ at $1350^{\circ}C$. Consequently, it is estimated that ZnO-$Pr_6O_{11}$-CoO-$Sm_2O_3$-based ZnO varistors, which $Sm_2O_3$ is added 1.0mol% is to be used as a basic composition of $Pr_6O_{11}$-based ZnO varistors.

• 환경위생공학
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• 제22권3호
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• pp.77-87
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• 2007

The ion exchange resins have been synthesized from chlormethyl styrene - 1,4 - divinylbenzene(DVB) with 1%, 3%, and 5%-crosslinking and macro cyclic ligand of OenNen-$H_4$ by copolymerization method and the adsorption characteristics of uranium(VI), iron(II) and samarium(III) metallic ions have been investigated in various experimental conditions. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, time, dielectric constant of solvent and crosslink on adsorption of metallic ions were investigated. The uranium ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in ethanol was in increasing order uranium ${UO_2}^{2+}>Fe^{2+}>Sm^{3+}$ ion. The adsorption was in order of 1%, 3%, and 5% crosslink resin and adsorption of resin decreased in proportion to order of dielectric constant of solvent.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.133-136
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• 2007

Perovskite-structured samarium strontium cobaltite (SSC), which is mixed ionic electronic conductor (MIEC), is considered as a promising cathode material for intermediate temperature-operating solid oxide fuel cell (SOFC) due to its high electrocatalytic property. Cathode material containing cobalt (Co) is unstable at high temperature and has a relatively high thermal expansion property. In this paper, Sm-Sr-(Co,Fe,Ni)-O system with perovskite and spinel structures was investigated in terms of electrochemical property and thermal expansion property, respectively. Area specific resistance (ASR) was measured by ac impedance spectroscopy to investigate the electrochemical property of cathode, and thermal expansion coefficient (TEC) was measured by using dilatometer. Micro structure of cathode was observed by scanning electron microscopy. Perovskite-structured $Sm_{0.5}Sr_{0.5}CoO_{3-\delta}$ showed the ASR of $0.87{\Omega}/cm^{2}$, and $Sm_{0.5}Sr_{0.5}NiO_{3-\delta}$, which actually has a spinel structure, showed the lowest TEC value of $13.3{\times}10^{-6}/K$.

• 한국환경과학회지
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• 제20권4호
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• pp.511-517
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• 2011

Ti-SBA-15 catalysts doped with samarium ion were synthesized using conventional hydrothermal method. The physical properties of Sm/Ti-SBA-15 catalysts have been characterized by XRD, FT-IR, DRS and PL. In addition, we have also examined the activity of these materials on the photocatalytic decomposition of methylene blue. The Sm/ Ti-SBA-15 was shown to have the mesoporous structure regardless of Sm ion doping. With doping amount of 1% lanthanide ion, the pore size and pore volume of Sm(Er, Cs)/Ti-SBA-15 decreased and the surface area increased. For the purpose of vibration characteristics on the Ti-SBA-15 and Sm/Ti-SBA-15 photocatalysts, the IR absorption at 960 $cm^{-1}$ commonly accepted the characteristic vibration of Ti-O-Si bond. 1% of Sm/Ti-SBA-15 had the highest photocatalytic activity on the decomposition of methylene blue but the catalysts doped with Er ions had lower activity in comparison with pure Ti-SBA-15 catalyst.

• 전기전자학회논문지
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• 제22권3호
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• pp.759-766
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• 2018

This paper presents a high-speed axial-flux machine which utilizes the idea of sinusoidal shaped pole combined with a consequent iron-pole. The target of the proposed machine is the cost reduction of the relatively expensive Samarium-Cobalt (SmCo) permanent magnet (PM) material and the torque per PM volume improvement by using sinusoidal consequent-pole rotor. The effectiveness of the proposed machine is validated by comparing it with conventional consequent-pole and with conventional PM machines using 3-D finite element method (FEM) simulations. The comparison and analysis is done in terms of back electro-motive force (back-EMF) harmonic contents, torque per PM volume and torque ripple characteristics. The simulation results show that the proposed machine is suitable and cost-effective for high-speed and high torque per PM volume applications. Furthermore, due to the consequent pole, the magnetic flux saturation and the overload current torque-capability are also presented and discussed in the paper.

• 분석과학
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• 제8권1호
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• pp.41-45
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• 1995

혼합된 희토류 원소의 농도를 정량적으로 분석하기 위하여 형광신호를 비선형 fitting하는 방법을 사용하였다. 본 연구에서는 Sm과 Eu 두 희토류 원소의 혼합된 형광을 비선형 fitting법으로 분리하여 그 농도를 분석하였다. 분석결과 감도면에서 한 가지 시료만 존재할 경우와 같은 정도인 sub-ppb의 검출한계를 나타냈으며, 혼합물에서 비선형 fitting법에 의해 얻어진 각 원소의 형광수명은 단일 원소만 존재하는 경우와 동일한 결과를 나타냄을 알 수 있었다.

• Progress in Superconductivity
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• 제8권1호
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• pp.22-26
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• 2006

Total Fluorine content in the precursor solution for MOD processing of YBCO coated conductors can be significantly reduced by synthesizing precursor solution with F-free Y & Cu precursor and Barium trifluoroacetate(TFA). It was shown that crack-free and uniform precursor films were formed after calcinations in humidified oxygen atmosphere. Less than 2 hours are required to finish the calcination process, and XRD measurement shows that $BaF_2,\;CuO,\;and\;Y_2O_3$ are major constituent of calcined precursor films. Film thickness after calcination was measured to be ${\sim}2.8$ um by applying slot-die coating method. In particular, addition of Samarium shows critical current of Ic=226 A/cm-w($Jc=3.4\;MA/cm^2$). Also discussed are recent developments in the reel-to-reel processing using F-free Y & Cu precursor solutions. It is shown that uniform and fast processing route to YBCO coated conductor with high Ic can be provided by employing F-free Y & Cu precursor solutions in MOD process.