Energy-weighted dynamical scattering simulations of electron diffraction modalities in the scanning electron microscope.

Transmission Kikuchi diffraction (TKD) has been gaining momentum as a high resolution alternative to electron back-scattered diffraction (EBSD), adding to the existing electron diffraction modalities in the scanning electron microscope (SEM). The image simulation of any of these measurement techniques requires an energy dependent diffraction model for which, in turn, knowledge of electron energies and diffraction distances distributions is required. We identify the sample-detector geometry and the effect of inelastic events on the diffracting electron beam as the important factors to be considered when predicting these distributions. However, tractable models taking into account inelastic scattering explicitly are lacking. In this study, we expand the Monte Carlo (MC) energy-weighting dynamical simulations models used for EBSD [1] and ECP [2] to the TKD case. We show that the foil thickness in TKD can be used as a means of energy filtering and compare band sharpness in the different modalities. The current model is shown to correctly predict TKD patterns and, through the dictionary indexing approach, to produce higher quality indexed TKD maps than conventional Hough transform approach, especially close to grain boundaries.

[1]  Marc De Graef,et al.  Dynamical Electron Backscatter Diffraction Patterns. Part I: Pattern Simulations , 2013, Microscopy and Microanalysis.

[2]  Matthew M Nowell,et al.  Introduction and comparison of new EBSD post-processing methodologies. , 2015, Ultramicroscopy.

[3]  G. Nolze,et al.  Physics-based simulation models for EBSD: advances and challenges , 2015, 1505.07982.

[4]  Alfred O. Hero,et al.  A Dictionary Approach to EBSD Indexing , 2015, ArXiv.

[5]  Daniela Roşca,et al.  A new method of constructing a grid in the space of 3D rotations and its applications to texture analysis , 2014 .

[6]  Carol Trager-Cowan,et al.  Many-beam dynamical simulation of electron backscatter diffraction patterns. , 2007, Ultramicroscopy.

[7]  David C. Joy,et al.  Monte Carlo Modeling for Electron Microscopy and Microanalysis , 1995 .

[8]  Q. Jia,et al.  Formation Mechanisms of High-density Growth Twins in Aluminum with High Stacking-Fault Energy , 2013 .

[9]  Roy H. Geiss,et al.  Transmission EBSD from 10 nm domains in a scanning electron microscope , 2012 .

[10]  Marc De Graef,et al.  Dictionary Indexing of Electron Channeling Patterns , 2017, Microscopy and Microanalysis.

[11]  P. Trimby,et al.  Orientation mapping of nanostructured materials using transmission Kikuchi diffraction in the scanning electron microscope. , 2012, Ultramicroscopy.

[12]  Alfred O. Hero,et al.  A Dictionary Approach to Electron Backscatter Diffraction Indexing* , 2015, Microscopy and Microanalysis.

[13]  N. C. Krieger Lassen,et al.  On the statistical analysis of orientation data , 1994 .

[14]  D. W. Scott,et al.  Multivariate Density Estimation, Theory, Practice and Visualization , 1992 .

[15]  D. Rosca New uniform grids on the sphere , 2010 .

[16]  D. Coates Kikuchi-like reflection patterns obtained with the scanning electron microscope , 1967 .

[17]  A. Wilkinson,et al.  Diffraction effects and inelastic electron transport in angle‐resolved microscopic imaging applications , 2017, Journal of microscopy.

[18]  M. P. Stoykovich,et al.  Specimen‐thickness effects on transmission Kikuchi patterns in the scanning electron microscope , 2014, Journal of microscopy.

[19]  L. Reimer Scanning Electron Microscopy: Physics of Image Formation and Microanalysis , 1984 .

[20]  Hide Yoshioka,et al.  Effect of Inelastic Waves on Electron Diffraction , 1957 .

[21]  S D Findlay,et al.  Thermal diffuse scattering in transmission electron microscopy. , 2011, Ultramicroscopy.

[22]  David C. Joy,et al.  Electron channeling patterns in the scanning electron microscope , 1982 .

[23]  John D. Austin,et al.  Adaptive histogram equalization and its variations , 1987 .

[24]  M. Graef,et al.  Theory of dynamical electron channeling contrast images of near-surface crystal defects. , 2014, Ultramicroscopy.

[25]  Haiyan Wang,et al.  High strength, epitaxial nanotwinned Ag films , 2011 .

[26]  A. Howie Inelastic scattering of electrons by crystals. I. The theory of small-angle in elastic scattering , 1963, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[27]  K. Marquardt,et al.  Quantitative electron backscatter diffraction (EBSD) data analyses using the dictionary indexing (DI) approach: Overcoming indexing difficulties on geological materials , 2017 .

[28]  David C. Joy,et al.  An empirical stopping power relationship for low‐energy electrons , 1989 .

[29]  M. Graef,et al.  Orientation sampling for dictionary-based diffraction pattern indexing methods , 2016 .