• 한국전기전자재료학회논문지
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• 제14권9호
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• pp.731-735
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• 2001

S $r_{0.89}$B $i_{2.4}$T $a_2$ $O_{9}$ (SBT) thin films are deposited on Pt-coated electrode(Pt/Ti $O_2$/ $SiO_2$/Si) using RF magnetron sputtering method. In the XRD pattern, the SBT thin films had (105) orientation. As annealing temperature was increased from $600^{\circ}C$ to 85$0^{\circ}C$, the intensities of peak were increased. In the SEM images, Bi-layered perovskite phase was crystallized above $650^{\circ}C$ and rod-like grains grew above 75$0^{\circ}C$. The maximum remanent polarization and the coercive electric field at annealing temperature of 75$0^{\circ}C$ are 11.60$\mu$C/$\textrm{cm}^2$ and 48kV/cm respectively. The dielectric constant and leakage current density at annealing temperature of 75$0^{\circ}C$ are 213 and 1.01x10$^{-8}$ A/$\textrm{cm}^2$, respectively. The fatigue characteristics of SBT thin filmsdid not change up to 10$^{10}$ switching cycles.s.s.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2002년도 추계학술대회 발표 논문집
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• pp.69-71
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• 2002

$(Bi, La)Ti_{3}O_{12}(BLT)$ ferroelectric thin films were prepared on $Al_{2}O_{3}/Si$ substrates by the sol-gel method. The as-coated films were post-annealed at the temperature of $650^{\circ}C$ and $700^{\circ}C$ for 30 min. The crystallinty, surface morphologies and electrical properties were affected by the annealing temperatures. The BLT films annealed at above $650^{\circ}C$ exhibited typical bismuth layered perovskite structures with (00$\ell$) preferred orientation. The granular shaped grains with a size of approximately 90nm was formed in the film sample annealed at $700^{\circ}C$. The memory window volatge of the BLT film was 2.5V. The leakage current of BLT films annealed at $650^{\circ}C$ was about $1\times10^{-7}A/\textrm{cm}^2$ at 3V.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권12호
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• pp.553-558
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• 2003

The A S $r_{0.7}$B $i_{2.6}$T $a_2$ $O_{9}$ (SBT)thin films are deposited on Pt-coated electrode(Pt/$TiO_2$/$SiO_2$/Si) using a RF magnetron sputtering method. The electrical properties of SBT capacitors with top electrodes were studied. In the XRD pattern, the SBT thin films in all annealing temperatures had (105) orientation. In the SEM images, Bi-layered perovskite phase was crystallized at 75$0^{\circ}C$ and grains largely grew in oxygen annealing atmosphere. The electrical properties of SBT capacitor with top electrodes represent a favorable properties in Pt electrode. The maximum remanent polarization and the coercive electric field with Pt electrode are 12.40C/$\textrm{cm}^2$ and 30kV/cm, respectively. The dielectric constant and leakage current density with Pt electrode is 340 and 6.8110$^{-10}$ A/$\textrm{cm}^2$, respectively.y.y.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1499-1501
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• 2003

The A $Sr_{0.7}Bi_{2.6}Ta_2O_9$(SBT)thin films are deposited on Pt-coated electrode(Pt/$TiO_2/SiO_2$/Si) using RF magnetron sputtering method. The electrical properties of SBT capacitors with top electrodes were studied. In the XRD pattern, the SBT thin films in all annealing temperatures had (105) orientation. In the SEM images, Bi-layered perovskite phase was crystallized at $750^{\circ}C$ and grains largely grew in oxygen annealing atmosphere. The electrical properties of SBT capacitor with top electrodes represents a favorable properties in Pt electrode. The maxim urn remanent polarization and the coercive electric field with Pt electrode are $12.40C/cm^2$and 30kV/cm respectively. The dielectric constant and leakage current density with Pt electrode is 340 and $6.8110^{-10}A/cm^2$ respectively.

• 한국재료학회지
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• 제31권9호
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• pp.488-495
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• 2021

Solid state grain growth (SSCG) is a method of growing large single crystals from seed single crystals by abnormal grain growth in a small-grained matrix. During grain growth, pores are often trapped in the matrix and remain in single crystals. Aerosol deposition (AD) is a method of manufacturing films with almost full density from nano grains by causing high energy collision between substrates and ceramic powders. AD and SSCG are used to grow single crystals with few pores. BaTiO₃ films are coated on (100) SrTiO₃ seeds by AD. To generate grain growth, BaTiO₃ films are heated to 1,300 ℃ and held for 10 h, and entire films are grown as single crystals. The condition of grain growth driving force is ∆G_max < ∆G_c ≤ ∆G_seed. On the other hand, the condition of grain growth driving force in BaTiO₃ AD films heat-treated at 1,100 and 1,200 ℃ is ∆G_c < ∆G_max, and single crystals are not grown.

• 한국초전도ㆍ저온공학회논문지
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• 제8권1호
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• pp.5-8
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• 2006

The growth properties of MOD-YBCO films were investigated. To enhance the growth rate of YBCO layer and inhibit the build-up of HF gas during the annealing process in TFA-MOD for YBCO coated conductors the method of low pressure annealing was employed. Total pressure was changed from 700Torr to 1Torr and its effect on growth of YBCO films was compared with atmospheric one. The lower Pressure was effective to control of the pore size in MOD method . Surface morphology of YBCO films processed at low total pres sure was rough and composed of random YBCO (103) grains. But large pores, usually observed at atmospheric process in MOD disappeared and also the number of pores was reduced at low pressure annealing. Also discussed ate the effects of Fluorine-free Y and Cu precursor solution on the development of microstructure. Dense surface me phology and with less and small pores can be provided through controlling Fluorine content.

• 원예과학기술지
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• 제17권3호
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• pp.337-340
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• 1999

장기 저장한 사과 화분의 활력을 측정하기 위하여 기본배지와 fluorescein diacetate(FDA)를 첨가한 배지를 slide glass 위에 얇게 도포한 후 기내발아율을 조사한 결과, FDA를 첨가한 배지에서는 화분 발아가 저하되었다. 따라서 FDA 용액을 이용한 형광염색반응법으로 사과 화분의 활력을 측정할 수 있는지 구명하기 위하여 10%의 sucrose 용액을 slide glass 위에 한방울 떨어뜨린 후 0.002%의 FDA를 첨가한 곳에 화분을 치상한 결과, 형광반응이 일어나는 치상 후 30분 경에 활력이 있는 화분은 자외선하에서 명확히 형광을 나타냈다. 기내발아율과 형광반응률을 측정한 결과, 39개월 장기 저장한 사과의 화분도 활력이 감소하지 않는 것으로 나타났다. 같은 방법으로 조사한 품종별 화분의 활력은 '후지' 와 '천추'가 가장 높게 나타났으며 '쓰가루'는 중간 정도, '조나골드'는 낮게 나타났다. 형광염색반응법에 의한 형광반응률은 대체로 기본배지에서의 발아율과 비슷하게 나타났으나 3개월간 저장한 '천추'의 화분은 형광반응률이 발아율보다 다소 높게 나타났다. 형광반응률과 발아율은 높은 정의 상관을 보여 형광염색 반응법에 의해 장기 저장 사과 화분의 활력을 편리하고 정확하게 측정할 수 있었다.

• 대한지리학회지
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• 제41권3호
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• pp.331-345
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• 2006

본 연구는 두만강 하류 지역에 대규모로 발달한 사구 지형의 분포 및 지표 환경, 퇴적물의 특성, 기원 및 형성과정을 밝히고, 두만강 하류 일대의 하천 및 해안 환경변화를 고찰하고자 한다. 이를 위해, Landsat, Spot 영상을 이용하여 지표피복을 분석하고, 2회의 현지 야외조사를 실시하였으며, 입도분석 및 현미경 관찰을 통해 사구 퇴적물 시료를 분석하였다. 위성영상에서 파악된 사질퇴적지형 요소들은 삼각주, 사취, 이동사구, 정착사구, 사주, 사주피복 수변식생으로 구분되었다. 사구 퇴적물에 대한 입도 분석 결과, 조사 지역 중 가장 상류 쪽에 해당하는 DM3과 DM4에서 하성보다는 해성 모래와의 상관성이 높게 나타났다. 이는 현재 사구를 이루는 모래의 입도 특성이 두만강 하류 지역의 현재 자연환경을 반영하고 있지 않음을 의미하는 것이다. 현미경 분석 결과, 모든 시료에서 풍화에 가장 강한 석영의 비율이 $65{\sim}83%$로 가장 높았다. 그러나 $30{\sim}40%$를 차지하는 광물 입자의 표면은 화학적 풍화를 받아 황색의 물질로 표면이 코팅되어 있으며, 물리 화학적 풍화에 의한 바늘 및 그물 모양의 거친 표면 형태와 에칭 피트가 나타난다.

• 한국재료학회지
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• 제9권8호
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• pp.804-809
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• 1999

테오스(TEOS)를 출발물질로 사용하여 건조조절제(DCCA;Dying Control Chemical Additives)를 첨가하지 않고, 솔-젤 법을 이용하여 Si(001) 단결정 기판 위에 실리카 박막을 제조하였다. 박막은 스핀 코팅 방법으로 테오스 =1 몰, 염산=0.05몰의 조건하에 메탄올, 증류수의 첨가량을 변화시키면서 젤화 완료시간, 박막의 두께, 균열 발생 여부, 박막의 결정성 등을 조사하였다. 그 결과 솔의 제화 완료시간은 메탄올 첨가량이 8몰일 때 가장 긴 640시간이었다. 코팅된 박막의 두께는 메탄올 첨가량이 많아질수록 감소하였다. 소결은 승온 속도$0.6^{\circ}C$/min으로 $500^{\circ}C$에서 1시간 행하였으며, 메탄올 첨가량이 0.8몰, 2몰일 때는 표면에서 균열이 발생하여 worm-like grain 구조를 가졌고, 메탄올 4몰인 경우에는 국부적으로 균열이 발생하였으나, 메탄올 양이 8몰 이상에서는 균열이 발생하지 않았다. 즉, 솔-젤 공정에서 균열 방지를 위해 첨가되는 건조조절제(DMF)를 첨가하지 않고도 용매인 메탄올과 증류수 혼합비를 조절, 표면장력을 제어함으로써 균열없는 박막을 제조하였다.

• 한국재료학회지
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• 제24권11호
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• pp.639-643
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• 2014

Hydrophilic $SiO_2$ layers were obtained by the atmospheric-pressure plasma treatment. Superhydrophobic $SiO_2$ layers were first deposited by the electrospray deposition method. The electrospunable solution that was prepared based on the solgel method was sprayed on Si (100) substrates. The surface of the electrosprayed $SiO_2$ layers consisted of the agglomeration of nano-sized grains, which led to a very high roughness and revealed a very high contact angle to water droplets over $162^{\circ}$. After having been exposed to the atmospheric $Ar/O_2$ plasma, the observed superhydrophobicity of the $SiO_2$ layers were greatly changed: a dramatic variation of the water contact angle from $162^{\circ}$ to $3^{\circ}$, namely realization of superhydrophillicity. Interestingly, the surface microstructure was almost preserved. According to the XPS analysis, it is more likely that thanks to the plasma exposure, the surface of $SiO_2$ layers will be cleaned in terms of organic species that are hydrophobic-inducing, consequently leading to the hydrophilic nature observed for the plasma-exposed $SiO_2$ layers.