• 한국자기학회:학술대회 개요집
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• 한국자기학회 2011년도 임시총회 및 하계학술연구발표회
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• pp.17-18
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• 2011

• 세라미스트
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• 제12권4호
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• pp.70-77
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• 2009

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2012년도 임시총회 및 하계학술연구발표회
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• pp.56-57
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• 2012

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2016년도 자성 및 자성재료 국제학술대회
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• pp.75-75
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• 2016

• 분석과학
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• 제14권4호
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• pp.317-323
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• 2001

아크릴로니트릴을 제조하기 위한 가암모니아 산화(ammoxidation) 공정에 쓰이는 몬산토 촉매의 용해방법을 연구하였다. 실리카가 지지체인 이 촉매는 마이크로파 용해장치를 이용하여 염산, 플루오르화 수소산 및 과산화수소의 혼합산으로 녹이는 것이 가장 효과적이었다. 이 장치로 녹일 때 용기 내의 압력이 높아 안전장치가 작동될 경우, 규소는 휘발할지라도 안티몬, 몰리브덴, 철, 비스무트 및 우라늄은 휘발하지 않았다. 유도결합 플라스마 원자방출분광법으로 측정한 결과 $SiO_2$ $50.5{\pm}0.4%$, $Sb_2O_3$ $29.6{\pm}0.6%$, $UO_2$ $10.2{\pm}0.1%$, $Fe_2O_3$ $6.1{\pm}0.1%$, $MoO_3$ $0.73{\pm}0.01%$ 및 $Bi_2O_3$ $0.49{\pm}0.01%$이었으며, 기준 값과의 상대 오차는 비스무트를 제외하고 모두 ${\pm}10%$ 이내였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.264-267
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• 2004

[ $Bi_{3.25}La_{0.75}Ti_3O_{12}$ ] (BLT) thin films were prepared by using metal organic decomposition method onto the $LaNiO_3$ (LNO) bottom electrode. Both the structure and morphology of the films were analyzed by x-ray diffraction (XRD) and atomic force microscope (AFM). Even at low temperatures ranging from 450 to $650^{\circ}C$, the BLT thinfilms were successfully deposited on LNO bottom electrode and exhibited (117) orientation. The BLT thin films annealed as low as $600^{\circ}C$ showed excellent ferroelectricity, higher remanent polarization and no significant degradation of switching charge at least up to $5{\times}10^9$ switching cycles at a frequency of 100 kHz and 5 V. For the annealing temperature of $600^{\circ}C$, the remanent polarization Pr and coercive field were $23.5\;C/cm^2$ and 120 kV/cm, respectively.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.417-417
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• 2016

Global environmental deterioration has become more serious year by year and thus scientific interests in the renewable energy as environmental technology and replacement of fossil fuels have grown exponentially. Photoelectrochemical (PEC) cell consisting of semiconductor photoelectrodes that can harvest light and use this energy directly to split water, also known as photoelectrolysis or solar water splitting, is a promising renewable energy technology to produce hydrogen for uses in the future hydrogen economy. A major advantage of PEC systems is that they involve relatively simple processes steps as compared to many other H2 production systems. Until now, a number of materials including TiO2, WO3, Fe2O3, and BiVO4 were exploited as the photoelectrode. However, the PEC performance of these single absorber materials is limited due to their large charge recombinations in bulk, interface and surface, leading low charge separation/transport efficiencies. Recently, coupling of two materials, e.g., BiVO4/WO3, Fe2O3/WO3 and CuWO4/WO3, to form a type II heterojunction has been demonstrated to be a viable means to improve the PEC performance by enhancing the charge separation and transport efficiencies. In this study, we have prepared a triple-layer heterojunction BiVO4/WO3/SnO2 photoelectrode that shows a comparable PEC performance with previously reported best-performing nanostructured BiVO4/WO3 heterojunction photoelectrode via a facile solution method. Interestingly, we found that the incorporation of SnO2 nanoparticles layer in between WO3 and FTO largely promotes electron transport and thus minimizes interfacial recombination. The impact of the SnO2 interfacial layer was investigated in detail by TEM, hall measurement and electrochemical impedance spectroscopy (EIS) techniques. In addition, our planar-structured triple-layer photoelectrode shows a relatively high transmittance due to its low thickness (~300 nm), which benefits to couple with a solar cell to form a tandem PEC device. The overall PEC performance, especially the photocurrent onset potential (Vonset), were further improved by a reactive-ion etching (RIE) surface etching and electrocatalyst (CoOx) deposition.

• 한국표면공학회지
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• 제45권2호
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• pp.61-69
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• 2012

Alloys of Fe-(5, 10, 15)Al and Fe-(10, 20, 30, 40)Cr were corroded at 700 and $800^{\circ}C$ for 70 hr in either atmospheric air or 1 atm of Ar+$1%SO_2$ gases. In these atmospheres, Fe-5Al and Fe-10Cr alloys displayed poor corrosion resistance. In atmospheric air, Fe-5Al alloys formed oxide nodules, while Fe-10Cr alloys formed thick scales and internal oxides. In Ar+$1%SO_2$ gases, Fe-5Al and Fe-10Cr alloys formed thick, nonadherent bi-layered scales, which grew primarily by the outward diffusion of Fe ions and inward diffusion of oxygen and sulfur ions. By contrast, in atmospheric air and Ar+$1%SO_2$ gases, Fe-(10, 15)Al and Fe-(20, 30, 40)Cr alloys displayed good corrosion resistance by forming $Al_2O_3$ and $Cr_2O_3$ layers on the surface, respectively.

• 한국자기학회지
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• 제24권3호
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• pp.71-75
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• 2014

정비조성으로 성장시킨 $LiTaO_3$ 단결정 및 비정비조성으로 성장시킨 $LiTaO_3$ 단결정 내에 불순물로 도핑된 $Fe^{3+}$ 상자성 불순물 이온의 바닥 상태에서의 에너지 준위를 계산하였다. $LiTaO_3$ 단결정 내에서 육방정계 대칭성을 갖는 $Fe^{3+}$ 이온의 전자 상자성 공명 상수인 분광학적 분리인자 g 및 영자기장 갈라지기 D 값을 이용하여 6개의 에너지 준위 사이의 에너지 준위를 계산하였다. 자기장을 결정학적 주축 ([100], [001], [111])과 나란하게 가하여 자기장을 증가시켜 감에 따라 얻은 에너지 준위 갈라지기는 자기장을 가한 방향에 따라서 서로 다른 값을 나타내었다. ${\mid}{\pm}5/2$ > ${\leftrightarrow}{\mid}{\pm}3/2$ >및 ${\mid}{\pm}3/2$ > ${\leftrightarrow}{\mid}{\pm}1/2$ > 사이의 전이에서 계산한 영자기장 갈라지기 값은 정비조성으로 성장시킨 $LiTaO_3$ 단결정과 비정비조성으로 성장시킨 단결정의 경우에 각각 12.300 GHz, 6.150 GHz와 59.358 GHz, 29.679 GHz이다. 결정성장 조건에 따라 에너지 준위가 상당히 다른 것으로 나타났다.

• 한국전기전자재료학회논문지
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• 제15권5호
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• pp.383-387
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• 2002

N-channel metal-ferroelectric-insulator-semiconductor field-effect-transistors (MFISFET's) by using $SrBi_2Ta_2O_9$/Silicon Nitride/Si (100) structure were fabricated. The fabricated devices exhibit comfortable memory windows, fast switching speeds, good fatigue resistances, and long retention times that are suitable for advanced ferroelectric memory applications. The estimated switching time and polarization ($2P_r$) of the fabricated FET measured at applied electric field of 376 kV/cm were less than 50 ns and about 1.5 uC/$\textrm{cm}^2$, respectively. The magnitude of on/off ratio indicating the stored information performance was maintained more than 3 orders until 3 days at room temperature. The $I_DV_G$ characteristics before and after being subjected to $10^11$ cycles of fatigue at a frequency of 1 MHz remained almost the same except a little distortion in off state.