A novel 3D absorption correction method for quantitative EDX-STEM tomography

Area of Science:

• Materials Science
• Analytical Chemistry
• Microscopy

Background:

• Energy dispersive X-ray (EDX) microanalysis is crucial for elemental composition determination.
• Absorption of X-rays in heterogeneous samples introduces significant artifacts, complicating accurate quantification.
• Existing methods struggle with unknown sample structures and compositions.

Purpose of the Study:

• To develop and validate a novel 3D method for correcting X-ray absorption in EDX microanalysis.
• To address the challenges posed by heterogeneous samples with unknown structures.
• To improve the accuracy of elemental quantification in complex materials.

Main Methods:

• Utilized scanning transmission electron microscopy (STEM) combined with EDX.
• Employed 3D reconstruction to map X-ray generation sites and paths.
• Implemented a voxel-by-voxel absorption correction based on estimated local composition.

Main Results:

• Demonstrated significant reduction of reconstruction artifacts caused by X-ray absorption.
• Identified and corrected for incomplete oxide recovery and erroneous carbon presence in a core/shell nanowire.
• Validated the method's accuracy using low-absorption X-ray lines.

Conclusions:

• The novel 3D absorption correction method effectively mitigates artifacts in EDX microanalysis.
• This technique enhances the reliability of elemental mapping for heterogeneous samples.
• Accurate quantitative analysis of complex nanostructures is now more achievable.