Error analysis of the crystal orientations and disorientations obtained by the classical electron backscatter diffraction technique

2015 ◽  
Vol 48 (3) ◽  
pp. 797-813 ◽  
Author(s):  
Farangis Ram ◽  
Stefan Zaefferer ◽  
Tom Jäpel ◽  
Dierk Raabe
Keyword(s):  
Electron Diffraction ◽  
Electron Backscatter Diffraction ◽  
Diffraction Theory ◽  
Classical Electron ◽  
Accuracy Measure ◽  
Electron Backscatter ◽  
Analytical Accuracy ◽  
Precision And Accuracy ◽  
Diffraction Patterns ◽  
Backscatter Diffraction

The fidelity – that is, the error, precision and accuracy – of the crystallographic orientations and disorientations obtained by the classical two-dimensional Hough-transform-based analysis of electron backscatter diffraction patterns (EBSPs) is studied. Using EBSPs simulated based on the dynamical electron diffraction theory, the fidelity analysis that has been previously performed using the patterns simulated based on the theory of kinematic electron diffraction is improved. Using the same patterns, the efficacy of a Fisher-distribution-based analytical accuracy measure for orientation and disorientation is verified.

scholarly journals Crystal orientation and detector distance effects on resolving pseudosymmetry by electron backscatter diffraction

2021 ◽  
Vol 54 (2) ◽  
pp. 513-522
Author(s):  
Edward L. Pang ◽  
Christopher A. Schuh
Keyword(s):  
Crystal Orientation ◽  
Electron Backscatter Diffraction ◽  
Detector Distance ◽  
Recent Emergence ◽  
Distance Effects ◽  
Electron Backscatter ◽  
Sample Position ◽  
Position And Orientation ◽  
Diffraction Patterns ◽  
Backscatter Diffraction

Accurately indexing pseudosymmetric materials has long proven challenging for electron backscatter diffraction. The recent emergence of intensity-based indexing approaches promises an enhanced ability to resolve pseudosymmetry compared with traditional Hough-based indexing approaches. However, little work has been done to understand the effects of sample position and orientation on the ability to resolve pseudosymmetry, especially for intensity-based indexing approaches. Thus, in this work the effects of crystal orientation and detector distance in a model tetragonal ZrO2 (c/a = 1.0185) material are quantitatively investigated. The orientations that are easiest and most difficult to correctly index are identified, the effect of detector distance on indexing confidence is characterized, and these trends are analyzed on the basis of the appearance of specific zone axes in the diffraction patterns. The findings also point to the clear benefit of shorter detector distances for resolving pseudosymmetry using intensity-based indexing approaches.

Many-beam dynamical simulation of electron backscatter diffraction patterns

2007 ◽  
Vol 107 (4-5) ◽  
pp. 414-421 ◽  
Author(s):  
Aimo Winkelmann ◽  
Carol Trager-Cowan ◽  
Francis Sweeney ◽  
Austin P. Day ◽  
Peter Parbrook
Keyword(s):  
Electron Backscatter Diffraction ◽  
Dynamical Simulation ◽  
Electron Backscatter ◽  
Diffraction Patterns ◽  
Backscatter Diffraction

A remark on ab initio indexing of electron backscatter diffraction patterns

2021 ◽  
Vol 54 (6) ◽  
Author(s):  
Adam Morawiec
Keyword(s):  
Single Crystal ◽  
Ab Initio ◽  
Diffraction Data ◽  
Electron Backscatter Diffraction ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Electron Backscatter ◽  
Diffraction Patterns ◽  
Backscatter Diffraction

There is a growing interest in ab initio indexing of electron backscatter diffraction (EBSD) patterns. The methods of solving the problem are presented as innovative. The purpose of this note is to point out that ab initio EBSD indexing belongs to the field of indexing single-crystal diffraction data, and it is solved on the same principles as indexing of patterns of other types. It is shown that reasonably accurate EBSD-based data can be indexed by programs designed for X-ray data.

Resolving pseudosymmetry in γ-TiAl using cross-correlation electron backscatter diffraction with dynamically simulated reference patterns

2018 ◽  
Vol 51 (3) ◽  
pp. 655-669 ◽  
Author(s):  
Brian Jackson ◽  
David Fullwood ◽  
Jordan Christensen ◽  
Stuart Wright
Keyword(s):  
Cross Correlation ◽  
Electron Backscatter Diffraction ◽  
Experimental Sample ◽  
Correct Orientation ◽  
Pattern Noise ◽  
Electron Backscatter ◽  
Diffraction Patterns ◽  
Backscatter Diffraction ◽  
Pattern Resolution ◽  
Pattern Center

Pseudosymmetry is a phenomenon that occurs when grains with different lattice parameters produce nearly identical diffraction patterns such that conventional electron backscatter diffraction (EBSD) techniques are unable to unambiguously differentiate the lattice orientations. This commonly occurs in materials with near-unity tetragonality, such as γ-TiAl. The current study uses cross-correlation EBSD to resolve pseudosymmetry in γ-TiAl. Three dynamically simulated reference patterns are generated for each point in the scan, one for each of the three potential pseudosymmetric orientations, which are subsequently correlated with the original pattern using six different methods in order to identify the correct orientation. The methods are first applied to a scan of dynamically simulated patterns, which is used to evaluate the sensitivity of the method to pattern resolution, pattern noise and pattern center error. It was determined that all six methods were 100% successful up to about 13 µm of pattern center error and pattern resolutions of about 80 × 80 pixels, and hence the methods were applied to an experimental sample of lamellar γ-TiAl. A hybrid combination of two of the methods was shown to successfully select the correct pseudosymmetry for about 96% of the points in the scan, improving upon the 70% accuracy of the Hough-based methods for the current study and 90% accuracy for previous studies resolving pseudosymmetry in lamellar γ-TiAl.

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