Comparison of Kikuchi diffraction geometries in the scanning electron microscope

Materials Characterization, vol. 222, pp. 114853

Abstract

Recent advances in scanning electron microscope (SEM) based Kikuchi diffraction have demonstrated the important potential for transmission and reflection methods, like transmission Kikuchi diffraction (TKD) and electron backscatter diffraction (EBSD). Furthermore, with the advent of compact direct electron detectors (DED) it has been possible to place the detector in a variety of configurations within the SEM chamber. This motivates the present work where we explore the similarities and differences of the different geometries that include on-axis TKD & off-axis TKD using electron transparent samples, as well as more conventional EBSD. Furthermore, we compare these with the newest method called “reflection Kikuchi diffraction” RKD where the sample is placed flat in the chamber and the detector is placed below the pole piece. Through remapping collected diffraction patterns , all these methods can be used to generate an experimental “diffraction sphere” that can be used to explore diffraction from any scattering vector from the unit cell, as well as the ability to perform band profile analysis. This diffraction sphere approach enables us to further probe specific differences between the methods, including for example thickness effects in TKD that can result in the generation of diffraction spots, as well as electron scattering path length effects that result in excess and deficiency variations, as well as inversion of bands in experimental patterns.

Authors 4

1. Tianbi Zhang

   University of British Columbia

   Affiliation as printed

   Department of Materials Engineering, The University of British Columbia, 309-6350 Stores Road, Vancouver, BC V6T 1Z4, Canada

2. Lukas Berners Aachen Institute for Physical Metallurgy and Materials Physics

   University of British Columbia · RWTH Aachen University

   Affiliation as printed

   Department of Materials Engineering, The University of British Columbia, 309-6350 Stores Road, Vancouver, BC V6T 1Z4, Canada

   Institute for Physical Metallurgy and Materials Physics, RWTH Aachen, 52056 Aachen, Germany

3. Jakub Holzer

   Thermo Fisher Scientific (Czechia)

   Affiliation as printed

   Thermo Fisher Scientific, Vlastimila Pecha 1282/12, 627 00 Brno, Czech Republic

4. T. Ben Britton corresponding

   University of British Columbia

   Affiliation as printed

   Department of Materials Engineering, The University of British Columbia, 309-6350 Stores Road, Vancouver, BC V6T 1Z4, Canada