• Title/Summary/Keyword: Scanning tunneling microscope

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Imaging and Manipulation of Benzene Molecules on Si Surfaces Using a Variable-low Temperature Scanning Tunneling Microscope

  • Hahn, J. R.
    • Bulletin of the Korean Chemical Society
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    • v.26 no.7
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    • pp.1071-1074
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    • 2005
  • A variable-low temperature scanning tunneling microscope (VT-STM), which operates from 77 to 350 K in ultrahigh vacuum, was built and used to study imaging and manipulation of benzene molecules on Si surfaces. Four types of benzene adsorption structures were first imaged on the Si(5 5 12)-2x1 surface. Desorption process of benzene molecules by tunneling electrons was studied on the Si(001)-2xn surface.

Construction of Ultra High Vacuum Scanning Tunneling Microscope (초고진공 Scanning Tunneling Microscope의 제작)

  • Son, Eun-Sook;Hong, Yeong-Kyu;Park, Chan
    • Journal of the Korean Vacuum Society
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    • v.3 no.4
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    • pp.377-381
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    • 1994
  • 초고진공(UHV) Scanning Tummeling Microscopy(STM)을 제작하였다. 8인치 프란지에 부착한 STM은 초고진공에서 시료의 통전가열이 가능하며 다른 표면 측정방법의 적용과시료처리가 용이하다. 외부로부터 초고진공을 깨지 않고 시료와 tip의 도입이 가능하며 tip을 가열할 수 있다. 완성된 장치로 Si(111)-7$\times$7 구조의 STM상을 얻었다.

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Construction of UHV Scanning Tunneling Microscope (초고진공용 주사형 터널링 현미경의 제작)

  • Koo, Ja-Yong;Kim, Dal-Hyun;Park, Hae-Won;Kim, Goo-Young;Lee, Se-Kyung
    • Journal of the Korean Society for Nondestructive Testing
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    • v.14 no.3
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    • pp.157-171
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    • 1994
  • A scanning tunneling microscope has been built, which can resolve atomic arrangements of conductors and semiconductors in ultra high vacuum below $10^{-11}$ Torr. Its background and operational principles are reviewed and the guide lines in building the scanning tunneling microscope are shown. The results of measurements for highly oriented pyrolytic graphite and Si(111) surface are presented.

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Direct Measurement of Spindle Motion Error Using a Regular Crystalline Lattice and a Scanning Tunneling Microscope

  • Chaikool, Patamaporn;Aketagawa, Masato;Okuyama, Eiki
    • International Journal of Precision Engineering and Manufacturing
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    • v.9 no.4
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    • pp.11-15
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    • 2008
  • Metrology tools with the ability to measure spindle motion error on the order of a nanometer are required due to recent advances in nanotechnology. We propose a direct measurement method for the radial motion error of a precision spindle using a regular crystalline lattice and a scanning tunneling microscope (STM). A highly oriented pyrolytic graphite (HOPG) crystal combined with an STM is used as a two-dimensional reference scale. The measurement principle and the preliminary experimental results are discussed in this article. The preliminary experimental results demonstrated that the proposed method has the capability to incorporate a two-dimensional encoder to measure the spindle motion error.

Theoretical Study of Scanning Probe Microscope Images of VTe2

  • Park, Sung-Soo;Lee, Jee-Young;Lee, Wang-Ro;Lee, Kee-Hag
    • Bulletin of the Korean Chemical Society
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    • v.28 no.1
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    • pp.81-84
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    • 2007
  • Ab initio periodic Hartree-Fock calculations with the full potential and minimum basis set are applied to interpretation of scanning tunneling microscope (STM) and atomic force microscope (AFM) images on 1TVTe2. Our results show that the simulated STM image shows asymmetry while the simulated AFM image shows the circular electron densities at the bright spots without asymmetry of electron density to agree with the experimental AFM image. The bright spots of both the STM and AFM images of VTe2 are associated with the surface Te atoms, while the patterns of bright spots of STM and AFM images are different.

System dynamics of scanning tunneling microscope unit

  • Yamada, Hikaru;Endo, Toshiro;Tsunetaka-Sumomogi;Fujita, Toshizo;Morita, Seizo
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10b
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    • pp.794-797
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    • 1988
  • G. Binnig and H. Rohrer introduced the Scanning Tunneling Microscope (STM) in 1982 and developed it into a powerful and not to be missed physical tool. Scanning tunneling Microscopy is a real space surface imaging method with the atomic or subatomic resolution in all three dimensions. The tip is scanned over the surface by two piezo translators mounted parallel (X-piezo and Y-piezo) to the surface and perpendicular to each other. The voltage applied to the third piezo (Z-piezo) translator mounted perpendicular to the surface to maintain the tunneling current through the gap at a constant level reflects then the topography of the surface. The feed back control loop for the constant gap current is designed using the automatic control technique. In the designing process of the feed back loop, the identification of the gap dynamics is very complex and has difficulty. In this research, using some suitable test signals, the system dynamics of the gap including the Z-piezo are investigated. Especially, in this paper, a system model is proposed for the gap and Z-piezo series system. Indicial response is used to find out the model. The driving voltage of the Z-piezo and the tunneling current are considered as input and output signals respectively.

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Nano-Scale Surface Observation of Cyclically Deformed Copper and Cu-Al Single Crystals (반복변형된 Cu 및 Cu-Al 단결정 표면형상의 나노-스케일 관찰)

  • 최성종;이권용
    • Tribology and Lubricants
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    • v.16 no.5
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    • pp.389-394
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    • 2000
  • Scanning Probe Microscope (SPM) such as Scanning Tunneling Microscope (STM) and Atomic Force Microscope (AEM) was shown to be the powerful tool for nano-scale characterization of material surfaces. Using this technique, surface morphology of the cyclically deformed Cu or Cu-Al single crystal was observed. The surface became proportionately rough as the number of cycles increased, but after some number of cycles no further change was observed. Slip steps with the heights of 100 to 200 nm and the widths of 1000 to 2000 nm were prevailing at the stage. The slipped distance of one slip system at the surface was not uniform, and formation of the extrusions or intrusions was assumed to occur such place. By comparing the morphological change caused by crystallographic orientation, strain amplitude, number of cycles or stacking fault energy, some interesting results which help to clarify the basic mechanism of fatigue damage were obtained. Furthermore, applicability of the scanning tunneling microscopy to fatigue damage is discussed.