Differential phase contrast from electrons that cause inner shell ionization

Area of Science:

• Electron Microscopy
• Materials Science
• Spectroscopy

Background:

• Differential Phase Contrast (DPC) imaging is typically studied with elastic scattering.
• Core-loss scattered electrons result from inner shell ionization.
• Understanding inelastic DPC is crucial for advanced microscopy.

Purpose of the Study:

• To investigate DPC formed from core-loss scattered electrons.
• To analyze the role of transition potentials and final states in calculations.
• To determine the conditions for element-selective contrast in inelastic DPC.

Main Methods:

• Utilizing a transition potential approach for core-loss electron scattering.
• Applying the phase object approximation.
• Conducting simulations to analyze contrast mechanisms and delocalization effects.

Main Results:

• Inelastic DPC is primarily due to preserved elastic contrast.
• Element selectivity in inelastic DPC depends on ionization interaction range and energy loss.
• Incoherent inelastic wavefields allow for robust interpretation in thicker samples compared to elastic DPC.

Conclusions:

• Inelastic DPC is achievable for thicker samples due to wavefield incoherence.
• High electron doses are necessary for discernible contrast.
• Signal-to-noise ratio improves with sample thickness, enhancing feasibility.