A Physically-Intuitive Method for Calculation of the Local Lattice Constant from a High-Resolution Transmission Electron Microscopy Image by Fourier Analysis

TL;DR

This paper introduces a physically intuitive Fourier-based method to determine local lattice constants in high-resolution TEM images, enabling spatially-resolved lattice analysis with an accessible software tool.

Contribution

The paper presents a novel Fourier analysis technique with Gaussian filtering for local lattice constant calculation, implemented in an open-source tool.

Findings

Accurate local lattice constants obtained at various positions.

Method successfully applied to high-resolution TEM images.

Open-source implementation available on nanoHUB.

Abstract

We have developed a physically-intuitive method to calculate the local lattice constant as a function of position in a high-resolution transmission electron microscopy image by performing a two-dimensional fast Fourier transform. We apply a Gaussian filter with appropriate spatial full-width-half-max (FWHM) bandwidth to the image centered at the desired location to calculate the local lattice constant (as opposed to the average lattice constant). Fourier analysis of the filtered image yields the vertical and horizontal lattice constants at this location. The process is repeated by stepping the Gaussian filter across the image to produce a set of local lattice constants in the vertical and horizontal direction as a function of position in the image. The method has been implemented in a freely available tool on nanoHUB.