Hostname: page-component-84b7d79bbc-rnpqb Total loading time: 0 Render date: 2024-07-28T14:20:40.287Z Has data issue: false hasContentIssue false
  • English
  • Français

Limits to Spatial Resolution in the HRTEM

Published online by Cambridge University Press:  02 July 2020

Michael A. O’Keefe
Michael A. O’Keefe*
Affiliation:
National Center for Electron Microscopy, University of California, LBL B72, Berkeley, CA94720
Get access

Extract

The resolution of the high-resolution transmission electron microscope is limited by the specimen as well as by the HRTEM. For specimens that beam-damage, image resolution depends upon electron energy and electron dose. For small-cell crystalline specimens, Bragg’s law quantizes allowable reso-lutions, preventing image resolution from reaching instrumental resolutiqn. Specimen thickness be-comes increasingly important at higher resolutions. For a resolution of d(Å), we need the specimen to diffract at u=1/d. Consideration of the intersection of the Ewald sphere with the specimen shape trans-form (fig. 1) shows that thickness must be less than For a resolution pr 1.0A at 300keV, thickness must be less than 100A; to achieve 0.7A requires halving this value to 50A (fig.l).

Resolution in an image depends on the spatial frequencies of the information (diffracted waves) trans-ferred from the amplitude spectrum (specimen exit-surface wavefunction) into the image intensity spec-trum (Fourier transform of the image intensity).

Type
The Limits of Image Resolution: Seeing is Believing
Information
Microscopy and Microanalysis , Volume 3 , Issue S2: Proceedings: Microscopy & Microanalysis '97, Microscopy Society of America 55th Annual Meeting, Microbeam Analysis Society 31st Annual Meeting, Histochemical Society 48th Annual Meeting, Cleveland, Ohio, August 10-14, 1997 , August 1997 , pp. 1165 - 1166
Copyright
Copyright © Microscopy Society of America 1997

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Ponce, F.A and O'Keefe, M.A., Proc. 44th Ann. Meeting EMSA, Albuquerque, N.M. (1986) 522–525.Google Scholar

2. Scherzer, O., J. Appl. Phys. 20 (1949) 20.CrossRefGoogle Scholar

3. O'Keefe, M.A., Ultramicroscopy 47 (1992) 282–297.CrossRefGoogle Scholar

4. O’Keefe, M.A., Proc. 37th Ann. Meeting EMSA, San Antonio, Texas (1979) 556–557.Google Scholar

5. O'Keefe, M.A.and Saxton, W.O., Proc. 41st Ann. Meeting EMSA, Phx, Arizona (1983) 288–289.Google Scholar

6. Frank, J., Optik 38 (1973) 519–536.Google Scholar

7. Wade, R.H. and Frank, J., Optik 49 (1977) 81–92.Google Scholar

8. Krivanek, O.L., Optik 43 (1975) 361–372.Google Scholar

9. Schiske, P., in Image Proc. and CAD, Ed. Hawkes, P.W., Acad. Press, London, (1973) 82–90.Google Scholar

10. Kirkland, E.J., Proc. 42nd Ann. Meeting EMSA, Detroit, Michigan, (1984) 432–433.Google Scholar

11. Van Dyck, D. and Op de Beeck, M., Proc. 12th Int. Congr. Electr. Mic, Seattle, Wash. (1990) 26–27.Google Scholar

12. Coene, W.Proc. 50th Ann. Meeting EMSA, Boston, Massachusetts, pp. 986–987, 1992.Google Scholar

13. Work supported by Director, Office of Energy Research, Office of Basic Energy Sciences, MaterialSciences Division of the U.S. Department of Energy, under contract No. DE-AC03-76SF00098Google Scholar.