Determining Projections of Grain Boundaries from Diffraction Data in Transmission Electron Microscope.

Area of Science:

• Materials Science
• Crystallography
• Electron Microscopy

Background:

• Grain boundaries (GBs) are critical microstructural features.
• Characterizing GBs typically involves disorientation and boundary plane orientation.
• Existing methods often require additional data acquisition for full characterization.

Purpose of the Study:

• To introduce a novel method for quantifying grain boundary (GB) projection width.
• To determine the orientation of the GB plane using this new parameter.
• To achieve comprehensive GB characterization from existing orientation map data.

Main Methods:

• Utilizing diffraction patterns collected in nanobeam diffraction mode via transmission electron microscopy (TEM).
• Applying non-negative matrix factorization (NMF) to pixel-by-pixel diffraction data.
• Measuring the width of the GB projection from the NMF analysis.

Main Results:

• Successfully quantified an additional GB parameter: the projection width.
• Demonstrated that GB projection width can be measured from existing diffraction patterns.
• Enabled determination of GB plane orientation using the measured projection width.

Conclusions:

• The novel method provides a more complete characterization of grain boundaries.
• It avoids the need for additional imaging, streamlining the analysis process.
• The technique, implemented in MATLAB, offers interpretable and visualizable results for GB analysis.