Determining the Bravais lattice using a single electron backscatter diffraction pattern

2015 ◽  
Vol 48 (1) ◽  
pp. 107-115 ◽  
Author(s):  
Lili Li ◽  
Ming Han
Keyword(s):  
Electron Backscatter Diffraction ◽  
A Priori ◽  
Single Electron ◽  
Bravais Lattice ◽  
Cell Parameters ◽  
Mineral Sample ◽  
Electron Backscatter ◽  
Ebsd Pattern ◽  
Backscatter Diffraction

Theab initioderivation of the Bravais lattice from the Kikuchi bands detected from a single electron backscatter diffraction (EBSD) pattern is successfully performed. The as-measured band widths and azimuths always suffer from gnomonic distortions which need to be corrected. A primitive reciprocal cell is first reconstructed by means of the corrected data and the cell parameters are then refined by least-squares analysis of hugely over-determined equations. This allows one to further derive a Niggli reduced cell from the primitive cell. The algorithm presented is not related to any crystal symmetry information and is therefore applicable to all crystal systems. The feasibility of the determination of the Bravais lattice type and parameters from a single EBSD pattern is demonstrated using a mineral sample without anya prioriinformation about its crystal structure. The novel application developed in the present work opens the way to the determination of the Bravais lattice of crystalline materials using scanning electron microscopy combined with the EBSD technique.

Distribution rules of systematic absences and generalized de Wolff figures of merit applied to electron backscatter diffraction ab initio indexing

2021 ◽  
Vol 54 (2) ◽  
pp. 624-635
Author(s):  
Ryoko Oishi-Tomiyasu ◽  
Tomohito Tanaka ◽  
Jun'ichi Nakagawa
Keyword(s):  
Ab Initio ◽  
Electron Backscatter Diffraction ◽  
Negative Influence ◽  
Bravais Lattice ◽  
Cell Parameters ◽  
Figures Of Merit ◽  
Distribution Rules ◽  
Electron Backscatter ◽  
Backscatter Diffraction ◽  
Orientation Determination

A new method for electron backscatter diffraction ab initio indexing is reported that adopts several methods originally invented for powder indexing. Distribution rules of systematic absences and error-stable Bravais lattice determination are used to eliminate the negative influence of non-visible bands and erroneous information from visible bands. In addition, generalized versions of the de Wolff figures of merit are proposed as a new sorting criterion for the obtained unit-cell parameters, which can be used in both orientation determination and ab initio indexing from Kikuchi patterns. Computational results show that the new figures of merit work well, similar to the original de Wolff Mn . The ambiguity of the indexing solutions is also pointed out, which happens in particular for low-symmetry cells and may generate multiple distinct solutions even if very accurate positions of band centre lines and the projection centre are given. It is supposed that this is the reason why indexing was successful in an orthorhombic case but not in a triclinic cell.

EBSDL: a computer program for determining an unknown Bravais lattice using a single electron backscatter diffraction pattern

2014 ◽  
Vol 47 (4) ◽  
pp. 1466-1468 ◽  
Author(s):  
Lili Li ◽  
Sheng Ouyang ◽  
Yanqing Yang ◽  
Ming Han
Keyword(s):  
Computer Program ◽  
Electron Backscatter Diffraction ◽  
Bravais Lattice ◽  
Chemical Information ◽  
Phase Identification ◽  
Crystalline Materials ◽  
The Poor ◽  
Electron Backscatter ◽  
Ebsd Pattern ◽  
Backscatter Diffraction

Electron backscatter diffraction (EBSD) patterns provide a wealth of crystallographic information but disappointingly low accuracy. Adopting a strategy of compensating the poor accuracy by the large amount of information, a computer program, EBSDL, has been successfully developed to determine the unknown Bravais lattice of bulk crystalline materials using a single EBSD pattern. Unlike programs that perform phase identification, the new application is completely independent of chemical information.

Electron backscatter diffraction determination of grain orientation and constituent phases

1999 ◽  
Vol 4 (2) ◽  
pp. 174-174
Author(s):  
Chen Xiaomei ◽  
Liu Jing ◽  
Wang Jianbo ◽  
Zhang Ruikang ◽  
Wang Dahai ◽  
...  
Keyword(s):  
Grain Orientation ◽  
Electron Backscatter Diffraction ◽  
Diffraction Determination ◽  
Electron Backscatter ◽  
Backscatter Diffraction

Application of Electron Backscatter Diffraction for Crystallographic Characterization of Tin Whiskers

2012 ◽  
Vol 18 (4) ◽  
pp. 876-884 ◽  
Author(s):  
Joseph R. Michael ◽  
Bonnie B. McKenzie ◽  
Donald F. Susan
Keyword(s):  
Electron Backscatter Diffraction ◽  
Growth Direction ◽  
Tin Whiskers ◽  
Physical Growth ◽  
Final Choice ◽  
Advantages And Disadvantages ◽  
Electron Backscatter ◽  
Backscatter Diffraction

AbstractUnderstanding the growth of whiskers or high aspect ratio features on substrates can be aided when the crystallography of the feature is known. This study has evaluated three methods that utilize electron backscatter diffraction (EBSD) for the determination of the crystallographic growth direction of an individual whisker. EBSD has traditionally been a technique applied to planar, polished samples, and thus the use of EBSD for out-of-surface features is somewhat more difficult and requires additional steps. One of the methods requires the whiskers to be removed from the substrate resulting in the loss of valuable physical growth relationships between the whisker and the substrate. The other two techniques do not suffer this disadvantage and provide the physical growth information as well as the crystallographic growth directions. The final choice of method depends on the information required. The accuracy and the advantages and disadvantages of each method are discussed.

Determination of crystal phase from an electron backscatter diffraction pattern

2009 ◽  
Vol 42 (2) ◽  
pp. 234-241 ◽  
Author(s):  
David J. Dingley ◽  
Stuart I. Wright
Keyword(s):  
Crystal Orientation ◽  
Electron Backscatter Diffraction ◽  
Hexagonal Phase ◽  
Three Dimensional ◽  
Lattice Parameters ◽  
Crystal Phase ◽  
Test Case ◽  
Electron Backscatter ◽  
Ebsd Pattern ◽  
Backscatter Diffraction

Electron backscatter diffraction (EBSD) is a scanning electron microscope-based technique principally used for the determination and mapping of crystal orientation. This work describes an adaptation of the EBSD technique into a potential tool for crystal phase determination. The process can be distilled into three steps: (1) extracting a triclinic cell from a single EBSD pattern, (2) identifying the crystal symmetry from an examination of the triclinic cell, and (3) determining the lattice parameters. The triclinic cell is determined by finding the bands passing through two zone axes in the pattern including a band connecting the two. A three-dimensional triclinic unit cell is constructed based on the identified bands. The EBSD pattern is indexed in terms of the triclinic cell thus formed and the crystal orientation calculated. The pattern indexing results in independent multiple orientations due to the symmetry the crystal actually possesses. By examining the relationships between these multiple orientations, the crystal system is established. By comparing simulated Kikuchi bands with the pattern the lattice parameters can be determined. Details of the method are given for a test case of EBSD patterns obtained from the hexagonal phase of titanium.

Denoising of crystal orientation maps

2019 ◽  
Vol 52 (5) ◽  
pp. 984-996 ◽  
Author(s):  
R. Hielscher ◽  
C. B. Silbermann ◽  
E. Schmidl ◽  
Joern Ihlemann
Keyword(s):  
Variational Methods ◽  
Crystal Orientation ◽  
Electron Backscatter Diffraction ◽  
Sliding Window ◽  
Orientation Data ◽  
Kernel Average Misorientation ◽  
Orientation Maps ◽  
Electron Backscatter ◽  
Backscatter Diffraction

This paper compares several well known sliding-window methods for denoising crystal orientation data with variational methods adapted from mathematical image analysis. The variational methods turn out to be much more powerful in terms of preserving low-angle grain boundaries and filling holes of non-indexed orientations. The effect of denoising on the determination of the kernel average misorientation and the geometrically necessary dislocation density is also discussed. Synthetic as well as experimental data are considered for this comparison. The examples demonstrate that variational denoising techniques are capable of significantly improving the accuracy of properties derived from electron backscatter diffraction maps.

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