Atomic resolution phase contrast imaging and in-line holography using variable voltage and dose rate

Area of Science:

• Materials Science
• Physics
• Chemistry

Background:

• Transmission electron microscopy (TEM) is crucial for atomic-scale material analysis.
• Achieving sub-Ångstrøm resolution requires advanced instrumentation and controlled imaging conditions.

Purpose of the Study:

• To demonstrate atomic resolution phase contrast imaging and focal series reconstruction using the TEAM 0.5 electron microscope.
• To investigate the impact of varying acceleration voltages and electron dose rates on imaging performance.
• To enable atomic resolution TEM for interfaces between soft and hard materials.

Main Methods:

• Utilized the TEAM 0.5 electron microscope with acceleration voltages from 20 to 300 kV.
• Employed a monochromator with ≤0.1 eV energy spread for dose variation and beam control.
• Performed focal series reconstruction and analyzed image contrast under varying dose rates.

Main Results:

• Achieved sub-Ångstrøm resolution, resolving the [200] atom dumbbell distance of 1.36 Å in silicon at 300, 80, and 50 kV.
• Atomic resolution <2 Å was observed at 20 kV, limited by aberrations.
• Lower dose rates resulted in sharper atom peaks, attributed to reduced beam-induced atom displacements.

Conclusions:

• The TEAM 0.5 microscope maintains uncompromised sub-Ångstrøm performance across a wide voltage range.
• Electron dose rate significantly affects atomic stability and image quality in high-resolution TEM.
• This development advances atomic resolution TEM for diverse material interfaces.