An improved method assigning three-dimensional atomic potentials to multiple slices in exit-wave simulations of...

Area of Science:

• Materials Science
• Crystallography
• Electron Microscopy

Background:

• The multislice method is crucial for simulating electron scattering in materials.
• Accurate atomic potential assignment is essential for reliable multislice simulations.
• Existing methods struggle with the 3D distribution of atomic potentials.

Purpose of the Study:

• To develop a novel analytical expression for calculating atomic potentials in the multislice method.
• To accurately project three-dimensional (3D) atomic potentials onto multiple slices, even those without atomic centroids.
• To improve the accuracy of electron microscopy simulations for complex crystal structures.

Main Methods:

• Proposed a simple analytical expression using Gaussian functions to fit electron atomic scattering factors.
• Calculated projected potential in reciprocal space, incorporating accurate 3D atomic positions.
• Considered the influence of atomic altitude fluctuations on potential assignment.

Main Results:

• Successfully projected 3D atomic potentials onto slices not containing the atomic centroid.
• Verified the method's performance using an silver (Ag) chain model.
• Demonstrated superior simulation results compared to the traditional multislice method for a complex oxide crystal (Ba6Nd2Ti4O17).

Conclusions:

• The proposed analytical method accurately calculates projected atomic potentials for multislice simulations.
• This approach enhances the simulation of electron wave propagation through materials with complex atomic arrangements.
• The improved simulation accuracy has significant implications for materials characterization using electron microscopy.