An experimental viewpoint on the information depth of EBSD.

Area of Science:

• Materials Science
• Crystallography
• Surface Science

Background:

• Electron backscatter diffraction (EBSD) is a crucial technique for analyzing crystal structures and microstructures.
• Understanding the information depth of EBSD is vital for accurate material characterization, especially when dealing with surface layers or coatings.
• Existing literature presents varied perspectives on EBSD's information depth, necessitating further experimental validation.

Purpose of the Study:

• To critically review and formulate a viewpoint on the information depth of electron backscatter diffraction (EBSD).
• To experimentally determine the information depth of EBSD by comparing it with scanning electron microscopy (SEM) contrast.
• To discuss the concepts and experimental approaches related to EBSD information depth.

Main Methods:

• Literature review on EBSD information depth.
• Experimental application of EBSD on a crystal partially covered with amorphous glass.
• Comparison of the last indexable EBSD patterns with the last discernible contrast in SEM micrographs at varying accelerating voltages (2-20 kV).

Main Results:

• EBSD patterns degraded in quality with increasing glass layer thickness.
• The last indexable EBSD pattern was observed at a depth comparable to SEM contrast at 4 kV on a non-tilted sample.
• This suggests EBSD's information depth is at least equivalent to SEM at specific low voltages.

Conclusions:

• The information depth of EBSD is comparable to, or potentially greater than, SEM imaging at lower accelerating voltages.
• Experimental evidence supports EBSD's capability to probe material structure through thin surface layers.
• Further discussion on the theoretical concepts and experimental methodologies for determining information depth is warranted.