• Title/Summary/Keyword: surface state

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Studies on the Atomic and Electronic Structures of Cu Adsorbed $Si(100)-2\times1$ Surface (Cu가 흡착된 $Si(100)-2\times1$ 표면의 원자구조 및 전자구조 연구)

  • 박래준;김정선;황찬국;안기석;박종윤
    • Journal of the Korean Vacuum Society
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    • v.7 no.4
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    • pp.293-299
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    • 1998
  • We have investigated the atomic and electronic structures of Cu-adsorbed Si(100)-2$\times$1 surface, by using LEED and UPS. In the UPS spectra, the weak structures (peaks) related to Cu silicide appeared for low coverages less than 1.3 ML at room temperature, and the intensity of Cu 3d band rapidly increased with respect to Cu coverages. The Cu silicide peaks become clear after Cu deposition at room temperature followed by high temperature annealing ($\geq 300^{\circ}C$) or for Cu deposited surface at the substrate temperature of $400^{\circ}C$. On the other hand, these structures disappeared by annealing at $750^{\circ}C$. At very low coverage, a surface state near Fermi level $(E_F)$ was observed at $400^{\circ}C$. According to the rigid band model, it seems to be originated from the surface empty state occupied partially with Cu 4s electron. In the LEED patterns, no Cu-induced superstructure observed for RT-depositions and post annealing, while there were several surface structures which depend on substrate temperatures and coverages. we observed the clean surface 2$\times$1+2$\times$2 phase for 1.5 ML at $400^{\circ}C$, the clean surface 2$\times$1+5$\times$1 phase for 0.5 ML at $450^{\circ}C$ and the clean surface 2$\times$1+2$\times$2+5$\times$2+5$\times$5+10$\times$2 mixed phases for 3 ML at $450^{\circ}C$.

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Assessment of Subsurface Damage in Ultraprecision Machined Semiconductors

  • Lucca, D.A.;Maggiore, C.J.;Rhorer, R.L.;Wang, Y.M.;Seo, Y.W.
    • Tribology and Lubricants
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    • v.11 no.5
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    • pp.156-161
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    • 1995
  • The subsurface damaged layer in ultraprecisison machined single crystal Ge was examined by ion channeling. Single crystal Ge surfaces were prepared by chemo-mechanical polishing, mechanical polishing with 1/4 gm diamond abrasive, single point diamond turning and ultraprecision orthogonal flycutting. The extent of subsurface lattice disorder was compared to the crystal's orginal surface quality. Ion channeling is seen to be useful for quantitative measure of lattice disorder in finely finished surfaces.

Liquid crystal alignment on the inkjet printed polyimide by using new alignment method

  • Hwang, J.Y.;Wonderly, H.;Chien, L.C.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.506-508
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    • 2007
  • We studied the nematic liquid crystal (NLC) alignment capability with a new alignment method utilizing an inkjet printed polyimide (PI) layer. A good, uniform LC alignment was achieved by the good PI printing using a new alignment method. The pretilt angle generated on the printed PI layer using the alignment method was almost the same as that on printed PI layer using rubbing alignment method. In addition, the good electro-optical performances of the new aligned twisted nematic (TN) cell with printed PI surface was obtained

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TRIBOLOGY:STATE OF THE ART AND ADVANCES IN CIS

  • Myshkin, N.K.
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1993.12a
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    • pp.1-31
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    • 1993
  • General state of research in fundamentals and applied areas of tribology is analysed with taldng account of changes in structure of funding and other aspects of transfer from centmllzed state economy to market one under simultaneous effect of USSR disintegration to independent states. Belarus Tribology Society as a coordinating body is presented. Activities of the major centers of research in friction, wear and lubrication are shown. Recent advances in development of analytical and calculation methods, surface characterization, wear testing and standardization, condition monitoring and tribomaterials are considered.

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A Study on Vortex Pair Interaction with Fluid Free Surface

  • Kim, K.H.;Kim, S.W.
    • Journal of ILASS-Korea
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    • v.10 no.4
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    • pp.26-31
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    • 2005
  • Today, the research to examine a fact that interaction between the air and the fluid free surface affects the steady state flow and air. We proved the interaction between vortex pairs and free surface on each condition that is created by the end of delta wings. Another purpose of this study is to investigate the effect of surface active material which call change the surface tension and we must consider when we refer to turbulent flow on surface tension. Therefore, this research examined the growth process of vortex pairs on condition of clean, contaminated free surface and wall after we made vortex pairs through counter rotating flaps. The results of this study suggest that vortex pairs in clean free surface rise safely but the vortex pairs in contaminated free surface and rigid, no slip is made secondary vortex or rebounding. However the secondary vortex in rigid, no slip is stronger than before. and we can find the vortex shape which roll up more completely. However, these will disappear by the effect of wall.

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Concerted Asynchronous Proton Transfer in H-Bonding Relay Model: An Implication of Green Fluorescent Protein

  • Kang, Baotao;Karthikeyan, S.;Jang, Du-Jeon;Kim, Heeyoung;Lee, Jin Yong
    • Bulletin of the Korean Chemical Society
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    • v.34 no.7
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    • pp.1961-1966
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    • 2013
  • Theoretical investigations have been performed for the ground state ($S_0$) and the first excited state ($S_1$) of the hydrogen bonded green fluorescent protein (GFP) model. The potential energy surface (PESs) of $S_0$ was obtained by B3LYP method and that of $S_1$ was obtained by CIS method. Based on the relative stabilities of species and the energy barriers for the proton transfer, it was found that proton transfer could take place both under the ground state and the first excited state. As determined by the proton motions along the reaction coordinate, both the ground state proton transfer (GSPT) and the excited state proton transfer (ESPT) are considered as a concerted and asynchronous process.

NEUTRON FIELD OF THE EARTH, ORIGIN AND DYNAMICS

  • Kuzhevskij, B.M.;Nechaev, O.Yu.;Panasyuk, M.I.;Sigaeva, E.A.;Volodichev, N.N.;Zakharov, V.A.
    • Journal of Radiation Protection and Research
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    • v.26 no.3
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    • pp.315-319
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    • 2001
  • It is shown, that both cosmic radiation (external source) and natural radioactive gases (inner source) are sources of neutrons near the Earth crust. Correlation between the Earth crust dynamics and variations of thermal and slow neutron flux near the Earth surface is studied. It is shown, that variations of neutron flux near the Earth crust can be used for short-term predicting of natural hazards.

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Polarization recording and reconstruction in the chalcogenide As-Ge-Se-S thin films (비정길 칼코게나이드 As-Ge-Se-S 박막에서 편광기록 재생)

  • 장선주;박종화;손철호;정홍배
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.9
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    • pp.781-785
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    • 2000
  • Chalcogenide glasses are suggested as a candidate for optical recording. In this study, we have investigated the holography recording and reconstruction of the polarization state in chalcogenide As$_{40}$ Ge$_{10}$Se$_{15}$ S$_{35}$ thin films. We have used a He-Ne laser light(633nm) to probe and record of the grating. Also the polarization state of object beam was modulated with a λ/4 wave plate. The polarization state of the +1st order diffracted beam was generated by readout of the grating with a linearly polarized reference beam. It was the same-handed polarization state as the polarization state of the recording beam. The result is shown that the diffraction efficiency of circularly polarized recording represents higher than other polarization state.ate.e.

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