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- J. M. Zuo
- Department of Materials Science and Engineering, F. Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, IL 61801, USA.
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- I. Vartanyants
- Department of Materials Science and Engineering, F. Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, IL 61801, USA.
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- M. Gao
- Department of Materials Science and Engineering, F. Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, IL 61801, USA.
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- R. Zhang
- Department of Materials Science and Engineering, F. Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, IL 61801, USA.
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- L. A. Nagahara
- Department of Materials Science and Engineering, F. Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, IL 61801, USA.
説明
<jats:p>Atomic imaging of three-dimensional structures has required a crystal in diffraction or a lens in electron imaging. Whereas diffraction achieves very high resolution by averaging over many cells, imaging gives localized structural information, such as the position of a single dopant atom. However, lens aberrations limit electron imaging resolution to about 1 angstrom. Resolution is reduced further by low contrast from weakscattering or from the limitations on electron dose for radiation-sensitive molecules. We show that both high resolution and high contrast can be achieved by imaging from diffraction with a nanometer-sized coherent electron beam. The phase problem is solved by oversampling and iterative phase retrieval. We apply this technique to image a double-wall carbon nanotube at 1-angstrom resolution, revealing the structure of two tubes of different helicities. Because the only requirement for imaging is a diffraction pattern sampled below the Nyquist frequency, our technique has the potential to image nonperiodic nanostructures, including biological macromolecules, at diffraction intensity–limited resolutions.</jats:p>
収録刊行物
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- Science
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Science 300 (5624), 1419-1421, 2003-05-30
American Association for the Advancement of Science (AAAS)