Comparison between Aberration-Corrected and Uncorrected EMs
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For electron microscopes without aberration corrections, the higher-order terms in Equation 3740 are overwhelmed by the positive, third-order spherical aberration and thus, we only need to consider the aberration coefficients up to third-order. However, for corrected microscopes the higher-order terms becomes dominant.

No Aberration Correction
Aberration Corrected
Third order aberrations corrected Fifth-order aberration-corrected
Illumination aperture size
Small Larger  
Beam current
Lower Six-fold increase for the same probe size (comparing with no aberration correction) [2] A factor of 100x increase for the same probe size (comparing with no aberration correction) [3]
Time for chemical mapping
Take over an hour [1] Take shorter times
EELS Measurement
Better electron collection by EEL spectrometer Most of electron beam may fall outside the entrance aperture of the EEL spectrometer if the collection optics are improved

 

 

 

 

 

 

 

 

[1] K. Kimoto, et al., Nature 450, 702 (2007).
[2] P. E. Batson, N. Dellby, O. L. Krivanek, Nature 418, 617 (2002).
[3] D. A. Muller, et al., Science, in press Feb 22 (2008).

 

 

 

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