Wikipedia

Michael A. O'Keefe

For other people with the same name, see Michael O'Keefe (disambiguation).

Michael A. O'Keefe (born 8 September 1942, in East Melbourne, Australia) is a physicist who has worked in materials science and electron microscopy.[1] He is perhaps best known for his production of the seminal computer code for modeling of high-resolution transmission electron microscopy (HRTEM) images;[2] his software was later made available[3] as part of the DeepView package[4] for remote electron microscopy[5] and control.[6][7] O'Keefe's tutorial on theory and application of high-resolution electron microscope image simulation is available online.[8]

O'Keefe has established methods of quantifying resolution quality, and methods of deriving accurate atom positions from high-resolution images.[9] He used these methods to help establish high-resolution electron microscopy as a precise science; in addition to its more-pedestrian role of pictorial confirmation of nano measurements, he demonstrated HRTEM's value in measurement of nano-properties.[10] The video[11] and associated slides[12] illustrate the role of his work in providing tools for nano-characterization.

O'Keefe designed and developed the one-Ångström microscope (OÅM) for the National Center for Electron Microscopy at Lawrence Berkeley National Laboratory based on an FEI Company CM300 microscope that he modified extensively to improve coherence and correct three-fold astigmatism. He was successful in breaking the "one-Ångström barrier" to resolution using his combination of hardware and software correction of microscope aberrations. He produced the first HRTEM images to show carbon atoms separated by less than one Ångström in diamond (0.89 Å)[13] and silicon atoms in crystalline silicon (0.78 Å)[14]—an example of his silicon work appears on a webpage at the Department of Energy.[15] His OÅM was the first HRTEM able to image the smallest metal atoms (lithium) in lithium battery materials.[16] Building on his work designing and operating his one-Ångström microscope (OÅM), O'Keefe produced the design for the LBNL TEAM (transmission electron aspheric microscope) able to resolve atoms in the deep sub-Ångström resolution region (less than 0.5 Å) using a hardware electron-wave phase-corrector (Cs corrector) in combination with a coherence-enhancing electron-beam monochromator.[17]

References

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  1. ^ "Profile". Archived from the original on 1 July 2007. Retrieved 25 March 2009.
  2. ^ O'Keefe, M. A.; Buseck, P. R.; Iijima, S. (1978). "Computed crystal structure images for high resolution electron microscopy" (PDF). Nature. 274 (5669): 322–324. Bibcode:1978Natur.274..322O. doi:10.1038/274322a0. S2CID 4163994.
  3. ^ "OLIS: On-Line Image Simulation and structure characterization for the Materials Microcharacterization Collaboratory".
  4. ^ Parvin, B.; Taylor, J.; Cong, G.; Okeefe, M. A.; Barcellos-Hoff, M. H. (1999). "Deep View". Proceedings of the 1999 ACM/IEEE conference on Supercomputing (CDROM) - Supercomputing '99. pp. 65–es. doi:10.1145/331532.331597. ISBN 1581130910. S2CID 6469606.
  5. ^ "Berkeley Lab Currents -- June 12, 1998".
  6. ^ Preuss, Paul. "Look Deep, Look Far: Remote Microscopy and Telescopy". Archived from the original on 13 April 2021.
  7. ^ O'Keefe, M.; Parvin, B.; Owen, D.; Taylor, J.; Westmacott, K.; Johnston, W.; Dahmen, U. "Automation for on-line remote-control in-situ electron microscopy". escholarship.org. Lawrence Berkeley National Laboratory. Retrieved 1 June 2024.
  8. ^ O'Keefe, M. A. (August 1994). "Interpretation of HRTEM images by image simulation: An introduction to theory and practice".
  9. ^ "HRTEM imaging of atoms at sub-Ångström resolution". Archived from the original on 13 July 2012. Retrieved 8 July 2010.
  10. ^ O'Keefe, Michael A.; Allard, Lawrence F. (18 January 2004). "Sub-Angstrom electron microscopy for sub-Angstrom nano-metrology".
  11. ^ Workshop. Archived from the original on 13 November 2008. Retrieved 26 March 2009.
  12. ^ "Data Management workshop - Nanosciences". 16 March 2004. Archived from the original (PPT) on 29 June 2013.
  13. ^ "BBC News | Sci/Tech | Scientists see atoms in diamond".
  14. ^ "Berkeley Lab Currents -- May 18, 2001".
  15. ^ "The Scale of Things". Archived from the original on 1 February 2010. Retrieved 31 January 2010.
  16. ^ Shao-Horn, Yang; Croguennec, Laurence; Delmas, Claude; Nelson, E. Chris; O'Keefe, Michael A. (2003). "Atomic resolution of lithium ions in LiCoO2". Nature Materials. 2 (7): 464–467. Bibcode:2003NatMa...2..464S. doi:10.1038/nmat922. PMID 12806387. S2CID 34357573.
  17. ^ "HRTEM at half-Angstrom resolution: From OAM to TEAM". 2003. Retrieved 1 June 2024.
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