Tomographic spectroscopic imaging; an experimental proof of concept

Area of Science:

• Materials Science
• Spectroscopy
• Electron Microscopy

Background:

• Traditional electron energy loss spectroscopy (EELS) data cube acquisition using energy-filtered images is dose inefficient due to electron beam blockage.
• Scanning probe methods offer perfect dose efficiency but are limited by slow acquisition speeds and small fields of view in nanoprobes.

Purpose of the Study:

• To demonstrate a novel, dose-efficient method for acquiring EELS data cubes.
• To present practical implementations, a geometrical model for projection angles, and experimental validation of the proposed technique.

Main Methods:

• Acquiring a set of projections of the EELS data cube.
• Utilizing tomographic reconstruction to reconstruct the full data cube from projections.
• Developing a geometrical model for precise quantification of projection angles.

Main Results:

• Successful experimental demonstration of the projection-based EELS data acquisition method.
• Validation of the geometrical model for accurate angle quantification.
• First successful experimental tomographic reconstruction of an EELS data cube using this technique on a standard instrument.

Conclusions:

• The proposed method offers a significant improvement in dose efficiency for EELS data cube acquisition compared to conventional energy-filtered series.
• This technique enables faster and more comprehensive EELS analysis without compromising data quality.
• The practical demonstration and successful reconstruction pave the way for wider adoption of this advanced EELS methodology.