Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-13T03:43:39.066Z Has data issue: false hasContentIssue false

Physical Limits on Atomic Resolution

Published online by Cambridge University Press:  22 January 2004

D. Van Dyck
Affiliation:
Department of Physics, University of Antwerp, 2020 Antwerp, Belgium
S. Van Aert
Affiliation:
Delft Center for Systems and Control, Delft University of Technology, 2628 CD Delft, The Netherlands
A.J. den Dekker
Affiliation:
Delft Center for Systems and Control, Delft University of Technology, 2628 CD Delft, The Netherlands
Get access

Abstract

It is shown that the ultimate resolution is not limited by the bandwidth of the microscope but by the bandwidth (i.e., the scattering power) of the object. In the case of a crystal oriented along a zone axis, the scattering is enhanced by the channeling of the electrons. However, if the object is aperiodic along the beam direction, the bandwidth is much more reduced. A particular challenge are the amorphous objects. For amorphous materials, the natural bandwidth is that of the single atom and of the order of 1 Å−1, which can be reached with the present generation of medium voltage microscopes without aberration correctors. A clear distinction is made between resolving a structure and refining, that is, between resolution and precision. In the case of an amorphous structure, the natural bandwidth also puts a limit on the number of atom coordinates that can be refined quantitatively. As a consequence, amorphous structures cannot be determined from one projection, but only by using atomic resolution tomography. Finally a theory of experiment design is presented that can be used to predict the optimal experimental setting or the best instrumental improvement. Using this approach it is suggested that the study of amorphous objects should be done at low accelerating voltage with correction of both spherical and chromatic aberration.

Type
Research Article
Copyright
© 2004 Microscopy Society of America

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

REFERENCES

den Dekker, A.J. & van den Bos, A. (1997). Resolution: A survey. J Opt Soc Am A 14, 547557.Google Scholar
Rose, A. (1948). Television pickup tubes and the problem of vision. In Advances in Electronics and Electron Physics, Marton, L. (Ed.), pp. 131166. New York: Academic Press.
van den Bos, A. & den Dekker, A.J. (2001). Resolution reconsidered—Conventional approaches and an alternative. Adv Imag Electron Phys 117, 241360.Google Scholar
Van Dyck, D. & Op De Beeck, M. (1996). A simple intuitive theory for electron diffraction. Ultramicroscopy 64, 99107.Google Scholar
Van Dyck, D., Van Aert, S., den Dekker, A.J., & van den Bos, A. (2003). Is atomic resolution transmission electron microscopy able to resolve and refine amorphous structures? Ultramicroscopy 98, 2742.Google Scholar