skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Resolution Quality and Atom Positions in Sub-?ngstr?m Electron Microscopy

Abstract

John Cowley pioneered use of transmission electron microscopy (TEM) for high-resolution imaging and helped spur improvements in resolution that enabled researchers to pinpoint the positions of all but the lightest atoms within a crystal structure. Sub-{angstrom} capabilities allow imaging of even the lightest atoms. Initially achieved with software aberration correction (focal-series reconstruction of the specimen exit-surface wave), sub-{angstrom} imaging will become commonplace for next-generation electron microscopes with hardware-corrected lenses and monochromated electron beams. Currently, advanced HR-TEMs can image columns of light atoms (carbon, oxygen, nitrogen) in complex structures, including the lithium atoms present in battery materials. The ability to determine whether an image peak represents one single atom (or atom column) instead of several depends on the resolution of the HR-(S)TEM. Rayleigh's resolution criterion, an accepted standard in optics, was derived as a means for judging when two image intensity peaks from two sources of light (stars) are distinguishable from a single source. Atom spacings closer than the Rayleigh limit have been resolved in HR-TEM, suggesting that it may be useful to consider other limits, such as the Sparrow resolution criterion. From the viewpoint of the materials scientist, it is important to be able to use the image to determinemore » whether an image feature represents one or more atoms (resolution), and where the atoms (or atom columns) are positioned relative to one another (resolution quality). When atoms and the corresponding image peaks are separated by more than the Rayleigh limit of the HR-(S)TEM, it is possible to adjust imaging parameters so that relative peak positions in the image correspond to relative atom positions in the specimen. When atoms are closer than the Rayleigh limit, we must find the relationship of the peak position to the atom position by peak fitting or, if we have a suitable model, by image simulation.« less

Authors:
 [1];  [2];  [2]
  1. Lawrence Berkeley National Laboratory (LBNL)
  2. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
OSTI Identifier:
1003096
DOE Contract Number:  
DE-AC05-00OR22725
Resource Type:
Conference
Resource Relation:
Conference: Microscopy and Microanalysis 2005, Honolulu, HI, USA, 20050731, 20050804
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ATOMS; CARBON; CORRECTIONS; CRYSTAL STRUCTURE; ELECTRON BEAMS; ELECTRON MICROSCOPES; ELECTRON MICROSCOPY; IMAGES; LENSES; LITHIUM; MATERIALS; MICROANALYSIS; MICROSCOPY; NITROGEN; OPTICS; OXYGEN; PEAKS; RESOLUTION; TRANSMISSION ELECTRON MICROSCOPY; VISIBLE RADIATION

Citation Formats

O'Keefe, Michael A., Allard Jr, Lawrence Frederick, and Blom, Douglas Allen. Resolution Quality and Atom Positions in Sub-?ngstr?m Electron Microscopy. United States: N. p., 2005. Web.
O'Keefe, Michael A., Allard Jr, Lawrence Frederick, & Blom, Douglas Allen. Resolution Quality and Atom Positions in Sub-?ngstr?m Electron Microscopy. United States.
O'Keefe, Michael A., Allard Jr, Lawrence Frederick, and Blom, Douglas Allen. Sat . "Resolution Quality and Atom Positions in Sub-?ngstr?m Electron Microscopy". United States.
@article{osti_1003096,
title = {Resolution Quality and Atom Positions in Sub-?ngstr?m Electron Microscopy},
author = {O'Keefe, Michael A. and Allard Jr, Lawrence Frederick and Blom, Douglas Allen},
abstractNote = {John Cowley pioneered use of transmission electron microscopy (TEM) for high-resolution imaging and helped spur improvements in resolution that enabled researchers to pinpoint the positions of all but the lightest atoms within a crystal structure. Sub-{angstrom} capabilities allow imaging of even the lightest atoms. Initially achieved with software aberration correction (focal-series reconstruction of the specimen exit-surface wave), sub-{angstrom} imaging will become commonplace for next-generation electron microscopes with hardware-corrected lenses and monochromated electron beams. Currently, advanced HR-TEMs can image columns of light atoms (carbon, oxygen, nitrogen) in complex structures, including the lithium atoms present in battery materials. The ability to determine whether an image peak represents one single atom (or atom column) instead of several depends on the resolution of the HR-(S)TEM. Rayleigh's resolution criterion, an accepted standard in optics, was derived as a means for judging when two image intensity peaks from two sources of light (stars) are distinguishable from a single source. Atom spacings closer than the Rayleigh limit have been resolved in HR-TEM, suggesting that it may be useful to consider other limits, such as the Sparrow resolution criterion. From the viewpoint of the materials scientist, it is important to be able to use the image to determine whether an image feature represents one or more atoms (resolution), and where the atoms (or atom columns) are positioned relative to one another (resolution quality). When atoms and the corresponding image peaks are separated by more than the Rayleigh limit of the HR-(S)TEM, it is possible to adjust imaging parameters so that relative peak positions in the image correspond to relative atom positions in the specimen. When atoms are closer than the Rayleigh limit, we must find the relationship of the peak position to the atom position by peak fitting or, if we have a suitable model, by image simulation.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sat Jan 01 00:00:00 EST 2005},
month = {Sat Jan 01 00:00:00 EST 2005}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share: