Nanoscale voxel spectroscopy by simultaneous EELS and EDS tomography

Area of Science:

• Materials Science
• Analytical Chemistry
• Electron Microscopy

Background:

• Electron tomography (ET) in transmission electron microscopy (TEM) provides 3D structural information.
• Advanced imaging and data processing can enhance the information content of 3D reconstructions.
• Analytical techniques are crucial for materials characterization at the nanoscale.

Purpose of the Study:

• To apply simultaneous electron energy-loss spectroscopy (EELS) and energy-dispersive X-ray spectroscopy (EDS) to scanning TEM tomography.
• To develop methods for 3D reconstruction of analytical tomograms with nanoscale resolution.
• To enable 3D nanoscale elemental quantification and analysis.

Main Methods:

• Simultaneous EELS and EDS acquisition during scanning TEM tomography.
• Refined tilt alignment procedures for accurate reconstruction.
• Multivariate statistical analysis and total-variation minimization for data processing.
• Reconstruction of four-dimensional spectrum volumes.

Main Results:

• 3D reconstruction of analytical tomograms for materials science samples.
• Generation of volumetric elemental maps at the nanometer scale.
• Reconstruction of EDS, low-loss, and core-loss EELS spectra as 4D spectrum volumes.
• Demonstration of 3D localized elemental analysis from reconstructed spectra.

Conclusions:

• The integrated approach extends TEM tomography capabilities for materials analysis.
• 3D nanoscale elemental quantification is achievable using simultaneous EELS-EDS in STEM tomography.
• This opens new pathways for detailed 3D characterization of materials.