Calculations of spherical aberration-corrected imaging behaviour.

Area of Science:

• Materials Science
• Physics
• Electron Microscopy

Background:

• Transmission electron microscopy (TEM) is vital for nanoscale material analysis.
• Optimizing operating conditions is key to achieving high-resolution imaging.
• Aberrations like C3, C5, and Cc limit resolution in TEM.

Purpose of the Study:

• To compare optimal operating conditions for C3-corrected TEMs.
• To evaluate the impact of C3 correction strategies (C5 vs. Cc compensation) on contrast transfer functions.
• To assess the performance of these conditions in advanced monochromated instruments.

Main Methods:

• Comparison of contrast transfer functions (CTFs) and wave aberration functions.
• Analysis of two C3-corrected operating conditions: C5-limited and Cc-limited.
• Multislice simulations of silicon (Si) and diamond structures.

Main Results:

• C5-limited correction provides flatter transfer to the information limit compared to Cc-limited correction.
• Cc-limited correction exhibits oscillatory transfer at high spatial frequencies, more pronounced in monochromated instruments.
• Si [110] resolution is minimally affected by C5 aberration, while diamond [110] resolution is restricted at sub-0.1 nm separations.

Conclusions:

• The C5-limited C3-correction strategy is superior for achieving high-resolution TEM imaging, especially for materials with sub-0.1 nm interatomic distances.
• Monochromated instruments benefit significantly from optimized aberration correction due to their enhanced capabilities.
• Careful selection of operating conditions is essential for faithful structural resolution in advanced TEM.