Effective Pattern Intensity Artifacts Treatment for Electron Diffractive Imaging

Francesco Scattarella,Dritan Siliqi,Liberato De Caro,Elvio Carlino

doi:10.3390/cryst7070186

Abstract

We present a method to treat spurious intensities in electron diffraction experiments. Coherent electron diffraction imaging requires proper data reduction before the application of phase retrieval algorithms. The presence of spurious intensities in the electron diffraction patterns makes the data reduction complicated and time consuming and jeopardizes the application of mathematical constraints to maximize the information that can be extracted from the experimental data. Here we show how the experimental diffraction patterns can be treated to remove the unwanted artifacts without corrupting the genuine intensities scattered by the specimen. The resulting diffraction patterns are suitable for the application of further processes and constraints aimed at deriving fundamental structural information by applying phase retrieval algorithms or other approaches capable of deriving quantitative atomic resolution information about the specimen structure.

Highlights

Transmission Electron Microscopy (TEM) is widely used to investigate the properties of matter at atomic resolution [1,2]
EDI recently demonstrated its capability to image the structure of matter at atomic resolution, overcoming the limitation of High Resolution TEM (HRTEM) due to electron lens aberrations
EDI requires a time consuming data reduction that obliges the direct intervention of skilled scientists to handle and process the data to obtain a proper set of diffracted intensities on which phase retrieval algorithms can be efficiently and safely applied

Summary

Introduction

Transmission Electron Microscopy (TEM) is widely used to investigate the properties of matter at atomic resolution [1,2]. The ultimate resolution of a TEM experiment is limited by the aberrations of the electron lenses that only recently have been successfully partially compensated, by using computer assisted magnetic multipole correctors, pushing the resolution of High Resolution TEM (HRTEM). Experiments to about 50 pm, but not yet achieving the diffraction limit [3,4]. Since the work of Scherzer in 1936 [5], the need to overcome the resolution limits has led to the development of new methods capable of retrieving the specimen properties at better resolution despite the aberrations. The exit wave reconstruction method was developed for this purpose [7].

Methods

Results

Discussion

Conclusion