• 제목/요약/키워드: Atomic interface

검색결과 392건 처리시간 0.031초

혼성복합재료의 계면 특성 분석 (Characterization of Interface in Hybrid Composites)

  • 하창식;안기열;조원재
    • 접착 및 계면
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    • 제1권1호
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    • pp.47-55
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    • 2000
  • In this article, the characterization of the interface of hybrid composites was discussed. Interfacial interaction in organic/inorganic hybrid composites, especially silica-containing hybrids can be characterized by fluorescence spectroscopy, small angle X-ray scattering (SAXS), scanning electron microscopy (SEM), atomic force microscopy (AFM), and $^{29}Si$ NMR spectroscopy measurements.

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Improving Interface Characteristics of Al2O3-Based Metal-Insulator-Semiconductor(MIS) Diodes Using H2O Prepulse Treatment by Atomic Layer Deposition

  • Kim, Hogyoung;Kim, Min Soo;Ryu, Sung Yeon;Choi, Byung Joon
    • 한국재료학회지
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    • 제27권7호
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    • pp.364-368
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    • 2017
  • We performed temperature dependent current-voltage (I-V) measurements to characterize the electrical properties of $Au/Al_2O_3/n-Ge$ metal-insulator-semiconductor (MIS) diodes prepared with and without $H_2O$ prepulse treatment by atomic layer deposition (ALD). By considering the thickness of the $Al_2O_3$ interlayer, the barrier height for the treated sample was found to be 0.61 eV, similar to those of Au/n-Ge Schottky diodes. The thermionic emission (TE) model with barrier inhomogeneity explained the final state of the treated sample well. Compared to the untreated sample, the treated sample was found to have improved diode characteristics for both forward and reverse bias conditions. These results were associated with the reduction of charge trapping and interface states near the $Ge/Al_2O_3$ interface.

원자층 증착법을 이용한 열전 소재 연구 동향 (Recent progress on Performance Improvements of Thermoelectric Materials using Atomic Layer Deposition)

  • 이승혁;박태주;김성근
    • 한국분말재료학회지
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    • 제29권1호
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    • pp.56-62
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    • 2022
  • Atomic layer deposition (ALD) is a promising technology for the uniform deposition of thin films. ALD is based on a self-limiting mechanism, which can effectively deposit thin films on the surfaces of powders of various sizes. Numerous studies are underway to improve the performance of thermoelectric materials by forming core-shell structures in which various materials are deposited on the powder surface using ALD. Thermoelectric materials are especially relevant as clean energy storage materials due to their ability to interconvert between thermal and electrical energy by the Seebeck and Peltier effects. Herein, we introduce a surface and interface modification strategy based on ALD to control the performance of thermoelectric materials. We also discuss the properties of the interface between various deposition materials and thermoelectric materials.

면진 원전 면진-비면진구간 연결 배관의 내진성능 평가 (Seismic Performance Evaluation of Piping System Crossing the Isolation Interface in Seismically Isolated NPP)

  • 함대기;박준희;최인길
    • 한국지진공학회논문집
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    • 제18권3호
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    • pp.141-150
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    • 2014
  • A methodology to evaluate the seismic performance of interface piping systems that cross the isolation interface in the seismically isolated nuclear power plant (NPP) was developed. The developed methodology was applied to the safety-related interface piping system to demonstrate the seismic performance of the target piping system. Not only the seismic performance for the design level earthquakes but also the performance for the beyond design level earthquakes were evaluated. Two artificial seismic ground input motions which were matched to the design response spectra and two historical earthquake ground motions were used for the seismic analysis of piping system. The preliminary performance evaluation results show that the excessive relative displacements can occur in the seismically isolated piping system. If the input ground motion contained relatively high energy in the low frequency region, we could find that the stress response of the piping system exceed the allowable stress level even though the intensity of the input ground motion is equal to the design level earthquake. The structural responses and seismic performances of piping system were varied sensitively with respect to the intensities and frequency contents of input ground motions. Therefore, for the application of isolation system to NPPs and the verification of the safety of piping system, the seismic performance of the piping system subjected to the earthquake at the target NPP site should be evaluated firstly.

탐침형 정보저장 기술을 위한 실리콘 탐침의 나노 마멸 특성에 관한 연구 (Nano-wear Characteristics of Silicon Probe Tip for Probe Based Data Storage Technology)

  • 이용하;정구현;김대은;유진규;홍승범
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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    • pp.552-555
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    • 2004
  • The reliability issue of the probe tip/recording media interface is one of the most crucial concerns in the Atomic Force Microscope (AFM)-based recording technology. In this work, the tribological characteristics of the probe/media interface were investigated by performing wear tests using an AFM. The ranges of applied normal load and sliding velocity for the wear test were 10 to 50nN and 2 to 20$\mu$m/s respectively. The damage of the probe tip was quantitatively as well as qualitatively characterized by Field Emission Scanning Probe Microscope (FESEM) analysis and calculated based on Archard s wear equation. It was shown that the wear coefficient of the probe tip was in the order of 10$^{-4}$ ~ 10$^{-3}$ , and significant contamination at the end of the probe tip was observed. Thus in order to implement the AFM-based recording technology, tribological optimization of the probe/media interface must be achieved.

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Processing Alarms in DYNAS: Basic Strategy

  • I. K. Hwang;Kim, J. T.;Lee, D. Y.;N. J. Na;S. J. Song;Park, J. C.;K. C. Kwon;C. S. Ham
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 1995년도 추계학술발표회논문집(1)
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    • pp.147-152
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    • 1995
  • During transients or major upsets, operators of a nuclear power plant are faced with a significant amount of information which oftentimes exceeds their capability of processing information in such a time-critical situation. To help resolve this problem of information overload, considerable work is underway worldwide to improve its man-machine interface systems (MMISs). The I&C research team of KAERI is developing a DYNamic Alarm processing System, called DYNAS, to suppress unnecessary or nuisance alarms, and at the same time, emphasize vital information. This paper describes our basic strategy to process alarms in DYNAS.

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Electron Accumulation in LaAlO3/SrTiO3 Interfaces by the Broken Symmetry of Crystal Field

  • 최희채;박하얀;정용재
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.452-452
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    • 2011
  • Using ab initio calculations, we reveal the origins of the extraordinarily increased electric conductivity of the LaAlO3/SrTiO3 interface. In both of the two (LaAlO3)m/ SrTiO3 heterojunction models (m=3, 5), the oxygen atoms in the cells were displaced toward the n-type interface and the Ti-centered octahedron structure was compressed along the [001] direction by the atomic reconstructions at the (LaAlO3)m/(SrTiO3)4 interfaces. As a result, the 3dxy orbital of the Ti atom was preferentially occupied due to the lowered energy state of the 3dxy orbital, which arises from the crystal field asymmetry. We reason that the extra electrons occupy the 3dxy orbital are accumulated at the interface by the displacement of the oxygen atoms. This accumulation contributes to the conductivity of the n-type interface. In addition, through a comparison of the atomic displacements and charge accumulation amounts between the two thickness models (m=3, 5), the thickness-dependency of the conductivity can be explained.

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