Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-28T10:13:32.625Z Has data issue: false hasContentIssue false

The NCEM One-Angstrom Microscope Project Reaches 0.89Å Resolution

Published online by Cambridge University Press:  02 July 2020

Michael A. O'Keefe*
Affiliation:
National Center for Electron Microscopy, MSD, LBNL B72, Berkeley, CA94720
Get access

Extract

Transmission electron microscopy to a resolution of 0.89Å has been achieved at the National Center for Electron Microscopy and is available to electron microscopists who have a requirement for this level of resolution. Development of this capability commenced in 1993, when the National Center for Electron Microscopy agreed to fund a proposal for a unique facility, a one- Ångstrom microscope (OÅM).2 The OÅM project provides materials scientists with transmission electron microscopy at a resolution better than one Angstrom by exploiting the significantly higher information limit of a FEG-TEM over its Scherzer resolution limit. To turn the misphased information beyond the Scherzer limit into useful resolution, the OÅM requires extensive image reconstruction. One method chosen was reconstruction from off-axis holograms; another was reconstruction from focal series of underfocused images. The OÅM is then properly a combination of a FEG-TEM (a CM300FEG-UT) together with computer software able to generate sub-Ångstrom images from experimental images obtained on the FEG-TEM.

Before the advent of the OÅM, NCEM microscopists relied on image simulation to obtain structural information beyond the TEM resolution limit.

Type
Microscopy Milestones of the Last Millenium
Copyright
Copyright © 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

1. For information on becoming an NCEM user, see <http://ncem.lbl.gov/frames/user.htm>>Google Scholar

2. O'Keefe, M.A., LBL Symposium on Microstructures of Materials, ed. Krishnan, K. (1993) 121-126.Google Scholar

3. O'Keefe, M.A.,.Buseck, P.R. and Iijima, S., Nature 274 (1978) 322324.CrossRefGoogle Scholar

4. O'Keefe, Michael A. & Kilaas, Roar, in Proc. 6th Pfefferkorn Conf. on Image and Signal Processing, Niagara Falls, Ontario (1987). Publ. as Scanning Microsc. suppl. 2 (1988) 225244.Google Scholar

5. Epicier, T., O'Keefe, M.A. and Thomas, G., (1990) Acta Cryst. A 46, 948962.CrossRefGoogle Scholar

6. O'Keefe, M.A., R&D Magazine (1999) <http://www.rdmag.eom/basics/l Omicroscopy.htm>' href=https://scholar.google.com/scholar?q=O'Keefe,+M.A.,+R&D+Magazine+(1999)+>Google Scholar

7. Wenk, H.-R., Downing, K.H., Meisheng, Hu, and O'Keefe, M.A., Acta Cryst. A 48 (1992) 700716CrossRefGoogle Scholar

8. O'Keefe, M.A., Ultramicroscopy 47 (1992) 282297.CrossRefGoogle Scholar

9. O'Keefe, Michael A., in 55th Ann. Proc. MSA, Cleveland, Ohio (1997) 11651166.Google Scholar

10. O'Keefe, M.A., these proceedings.Google Scholar

11. Turner, John H., O'Keefe, Michael A. & Mueller, Robert, 55th Ann. Proc. MSA, Cleveland, Ohio (1997) 11771178.Google Scholar

12. Wang, Y.C., O'Keefe, Michael A., Pan, Ming, Nelson, E.C., and Kisielowski, C. in Proc. XlVth Int. Congress for Electron Microscopy 1 (1998) 573574.Google Scholar

13. Bleeker, Arno J., Overwijk, Mark H.F. and Otten, Max T., 54th Ann. Proc. MSA, Minneapolis, MN (1997) 418419.Google Scholar

14. Wang, Y.C., Fitzgerald, A., Nelson, E.C., Song, C., O'Keefe, M.A. & Kisielowski, C., 57th Ann. Proc. MSA, Portland, Oregon (1999) 822823.Google Scholar

15. O'Keefe, M.A., in 37th Ann. Proc. EMSA, San Antonio, Texas (1979) 556557.Google Scholar

16. Coene, W.M.J., Thust, A., Beeck, M. Opde and Dyck, D. Van, Ultramicroscopy 64 (1996) 109135.CrossRefGoogle Scholar

17. Work supported by Director, Office of Science - through the Office of Basic Energy Sciences, Material Sciences Division, of the U.S. Department of Energy, under contract No. DE-AC03-76SF00098.Google Scholar