• Progress in Superconductivity
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• v.13 no.1
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• pp.7-11
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• 2011

The effects of Sm:Ba:Cu composition ratio in SmBCO coated conductor on their superconducting properties were investigated. The SmBCO coated conductors were fabricated by reactive co-evaporation method using EDDC(Evaporation using Drum in Dual Chamber) system. In this system, we could obtain various samples with different composition ratios in a batch by the technique providing composition gradient at deposition zone. From the specimens prepared by EDDC system, we found that composition ratio is uniform parallel to the drum axis, but gradient along the circumferential direction of the drum. We installed a shield having parallelogram open area between the deposition chamber and the evaporation chamber in EDDC system, and attached a 30 cm long template, which is parallel to drum axis, onto the drum surface. In this configuration, we could obtain SmBCO coated conductors having a gradient composition along the length of template. We measured the composition ratios and surface morphologies with periodic interval by SEM and EDAX, and confirmed the profile of composition ratio. We also measured critical current using non-contact Hall probe critical current measurement system and thereby could plot composition ratio vs. critical current. The maximum critical current was obtained, and the surface morphology with the shape of roof tile was observed at the corresponding composition ratio of Sm:Ba:Cu = 1.01:1.99:4.87. It was also found that composition ratio had an effect on not only critical current but also surface morphology.

• Journal of the Korean Ceramic Society
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• v.31 no.8
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• pp.920-926
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• 1994

Ta doped PZT thin films were prepared by a reactive sputtering method with a 3-gun magnetron co-sputter, and effects of Ta doping on physical and electrical properties of the films were studied. Within the doping range of 0 to 3.6 at%, Ta doping enhanced the crystallographic orientation of (110), but reduced that of (100). Ta doped PZT had a larger grain size of about 20 ${\mu}{\textrm}{m}$ compared with that of 5 ${\mu}{\textrm}{m}$ for un-doped PZT. Pits and holes of PZT films which used to appear with annealing at high temperature due to evaporation of PbO were much suppressed with addition of Ta. The leakage current could be reduced down to 1.27$\times$10-8 A/$\textrm{cm}^2$ and the charge storge density as large as 25.8$\mu$C/$\textrm{cm}^2$ was obtained.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.103-103
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• 2003

ZnO$_{1-x}$(또는 Zn$_{1+x}$O) 산화아연은 과잉의 아연(또는 oxygen vacancy)이 도우너(donor) 역할을 하는 비화학양론적 n형 산화물 반도체이다. ZnO는 높은 투과율을 가지고 온도나 주변환경에 대해 매우 안정하며, 또한 이미 상용화된 ITO (Indium tin oxide)에 비해 식각 특성이 우수하고, 수소 플라즈마에 대한 저항성이 크다는 장점 때문에 가스센서와 디스플레이용 소자 등 다양한 분야에 응용이 가능하다. ZnO 박막은 CVD, Reactive Magnetron Sputtering, Electron-beam Evaporation 등 여러 가지방법으로 제작할 수 있다. 본 연구에서는 형성된 박막의 구성성분이 타겟의 성분과 유사하고 낯은 기판온도에서도 박막이 형성되어지는 장점을 가지는 Pulsed Laser Deposition 방법을 사용하여 유리 기판위에 ZnO 박막을 형성하였다.다.

• 한국초전도학회:학술대회논문집
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• 2007.07a
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• pp.6-6
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• 2007

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.7-9
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• 2008

ITO thin film is generally fabricated by various. methods such as spray, CVD, evaporation, electron gun deposition, direct current electroplating, high frequency sputtering, and reactive DC sputtering. However, some problems such as peaks, bumps, large particles, and pin-holes on the surface of ITO thin film were reported, which caused the destruction of color quality, the reduction of device life time, and short-circuit. Chemical mechanical polishing (CMP) process is one of the suitable solutions which could solve the problems

• Electrical & Electronic Materials
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• v.5 no.4
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• pp.400-405
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• 1992

활성화 반응성 증착법으로 비저항 1.7*$10^{-3}$-8.0*$10^{-3}$ohm.cm, 전하운반자 농도 3.4*$10^{19}$-2.8*$10^{20}$$cm^{-3}$, 이동도 12-23$cm^{2}$/V.s, 금지대역 폭 3.35eV인 In/sib 2/ $O_{3}$박막을 KBr과 실리카 기판에 성장시켰다. 광투과율은 가시광선 영역에서 80% 이상을 나타냈으며 적외선 영역에서도 양호한 특성을 나타냈다. 박막성장시는 비정질 상태였으나 150.deg.C 이상에서 열처리했을 때 결정화현상이 관찰되었다.

• 한국초전도학회:학술대회논문집
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• 2008.08a
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• pp.24-24
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• 2008

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.101-102
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• 2000

The performance of ac plasma display panels (PDP) is influenced strongly by the surface glow discharge characteristics on the MgO thin films. This paper deals with the surface glow discharge characteristics and some physical properties of MgO thin films prepared by reactive RF planar unbalanced magnetron sputtering in connection with ac PDP. The samples prepared with the de bias voltage of -10V showed lower discharge voltage, lower erosion rate by ion bombardment, higher optic transparency and higher crack resistance in annealing process than those samples prepared by conventional magnetron sputtering or E-beam evaporation.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.10
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• pp.2418-2425
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• 1993

A two-dimensional transient heat transfer model for reactive gas assisted laser cutting process with a moving Gaussian heat source is developed using a numerical finite difference technique. The kerf width, melting front shape and temperature distribution were calculated by using the boundary-fitted coordinate system to handle the ejection of workpiece material and heat input from reaction and evaporation. An analytical solution for cutting front movement was adopted and numerical simulation was performed to calculate the temperature distribution and melting front thickness. To calculate the moving velocity of cutting front, the normal distribution of the cutting gas velocity was used. The kerf width was revealed to be dependent on the cutting velocity, laser power and cutting gas velocity.

• Electrical & Electronic Materials
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• v.4 no.4
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• pp.338-343
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• 1991

활성화된 반응성 증발법을 이용하여 비저항 .rho.=1*$10^{-3}$.OMEGA..cm, 이동도 .mu.=4*$10^{3}$$cm^{2}$/V.sec이고 두께가 약 400.angs.인 In$_{2}$O$_{3}$ 박막을 실온에서 유리기판에 생성시켰다. 광투과율은 파장 400-800nm범위에서 80% 이상으로 나타났고 구조는 무정형인 것으로 나타났다. 낮은 저항의 In$_{2}$O$_{3}$ 박막은 Ar과 $O_{2}$의 압력을 적적히 조절함으로서 얻을 수 있을 것으로 분석되었고 약 350.deg.C의 온도로 30분간 열처리로서 정형화할 수 있는 것으로 판단되었다. 또한 증발율, 이동도 및 저항과 캐리어 농도와의 상관관계도 고찰하여 보았다.