A refinable three-parameter equation for phenomenological absorption in quantitative electron microscopy -...

Area of Science:

• Materials Science
• Physics
• Crystallography

Background:

• Quantitative convergent-beam electron diffraction (QCBED) simulations require accurate models of electron scattering.
• Existing models, like the ATOM subroutine, are effective but may need refinement for unfiltered diffraction patterns.

Purpose of the Study:

• To derive a new three-term phenomenological equation for electron beam absorption in materials.
• To improve the accuracy of transmission electron microscopy (TEM) simulations, particularly for differential QCBED.

Main Methods:

• Developed a three-term equation for phenomenological absorption.
• Validated the equation against the ATOM subroutine's inelastic scattering factors across a wide range of elements and parameters.
• Investigated the refinement of equation coefficients for local and non-local scattering contributions.

Main Results:

• The derived equation accurately reproduces inelastic scattering factors (within a few percent) generated by the ATOM subroutine.
• The equation is applicable across elements Z=1-98, Debye-Waller parameters (0.05-2.0 Ų), scattering angles (0-6.0 Å⁻¹), and electron energies (1 keV-1 MeV).
• The equation's coefficients can be refined for improved suitability in unfiltered differential QCBED pattern matching.

Conclusions:

• The new three-term equation provides a robust and adaptable model for electron beam absorption in materials.
• This model enhances the capabilities of quantitative TEM simulations, especially for unfiltered QCBED analysis.
• The refined coefficients offer greater flexibility in modeling scattering phenomena for advanced materials characterization.