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The EBSD detector is located within the specimen chamber of the SEM at an angle of approximately 90° to the pole piece. The EBSD detector is typically a phosphor screen that is excited by the backscattered electrons.<ref name=":45" /> The screen is coupled to lens which focuses the image from the phosphor screen onto a [[charge-coupled device]] (CCD) or c[[CMOS|omplementary metal–oxide–semiconductor]] (CMOS) camera.<ref>{{Cite journal |last1=Goulden |first1=J. |last2=Trimby |first2=P. |last3=Bewick |first3=A. |date=2018-08-01 |title=The Benefits and Applications of a CMOS-based EBSD Detector |journal=Microscopy and Microanalysis |volume=24 |issue=S1 |pages=1128–1129 |doi=10.1017/s1431927618006128 |bibcode=2018MiMic..24S1128G |s2cid=139967518 |doi-access=free }}</ref>
In this configuration, as the backscattered electrons leave the sample, they interact with the [[Electric potential|Coulomb potential]] and also lose energy due to [[inelastic scattering]] leading to a range of scattering angles (θ<sub>hkl</sub>).<ref name=":45">{{Citation |last=Randle |first=Valerie |title=Theoretical Framework for Electron Backscatter Diffraction |date=2000 |work=Electron Backscatter Diffraction in Materials Science |pages=19–30 |editor-last=Schwartz |editor-first=Adam J. |place=Boston, MA |publisher=Springer US |doi=10.1007/978-1-4757-3205-4_2 |isbn=978-1-4757-3205-4 |editor2-last=Kumar |editor2-first=Mukul |editor3-last=Adams |editor3-first=Brent L. }}</ref><ref name=":19">{{Citation |last1=Eades |first1=Alwyn |title=Energy Filtering in EBSD |date=2009 |work=Electron Backscatter Diffraction in Materials Science |pages=53–63 |editor-last=Schwartz |editor-first=Adam J. |place=Boston, MA |doi=10.1007/978-0-387-88136-2_4 |isbn=978-0-387-88136-2 |last2=Deal |first2=Andrew |last3=Bhattacharyya |first3=Abhishek |last4=Hooghan |first4=Tejpal |editor2-last=Kumar |editor2-first=Mukul |editor3-last=Adams |editor3-first=Brent L. |editor4-last=Field |editor4-first=David P. }}</ref> The backscattered electrons form [[Kikuchi lines (physics)|Kikuchi lines]] – having different intensities – on an electron-sensitive flat film/screen (commonly phosphor), gathered to form a Kikuchi band. These Kikuchi lines are the trace of a hyperbola formed by the intersection of [[Walther Kossel|Kossel]] cones with the plane of the phosphor screen. The width of a Kikuchi band is related to the scattering angles and, thus, to the distance d<sub>hkl</sub> between lattice planes with Miller indexes h, k, and l.<ref name=":20">{{Cite journal |last1=Wilkinson |first1=Angus J. |last2=Britton |first2=T. Ben. |date=2012 |title=Strains, planes, and EBSD in materials science |journal=Materials Today |volume=15 |issue=9 |pages=366–376 |doi=10.1016/S1369-7021(12)70163-3 |doi-access=free }}</ref><ref>{{Cite journal |last1=Sawatzki |first1=Simon |last2=Woodcock |first2=Thomas G. |last3=Güth |first3=Konrad |last4=Müller |first4=Karl-Hartmut |last5=Gutfleisch |first5=Oliver |date=2015 |title=Calculation of remanence and degree of texture from EBSD orientation histograms and XRD rocking curves in Nd–Fe–B sintered magnets |journal=Journal of Magnetism and Magnetic Materials |volume=382 |pages=219–224 |doi=10.1016/j.jmmm.2015.01.046 |bibcode=2015JMMM..382..219S }}</ref> These Kikuchi lines and patterns were named after [[Seishi Kikuchi]], who, together with {{interlanguage link|Shoji Nishikawa|ja|西川正治}}, was the first to notice this diffraction pattern in 1928 using [[transmission electron microscopy]] (TEM)<ref>{{Cite journal |last1=Nishikawa |first1=S. |last2=Kikuchi |first2=S. |date=June 1928 |title=Diffraction of Cathode Rays by Mica |url=http://dx.doi.org/10.1038/1211019a0 |journal=Nature |volume=121 |issue=3061 |pages=1019–1020 |doi=10.1038/1211019a0 |bibcode=1928Natur.121.1019N |issn=0028-0836}}</ref> which is similar in geometry to X-ray Kossel pattern.<ref>{{Cite journal |last1=Tixier |first1=R. |last2=Waché |first2=C. |date=1970 |title=Kossel patterns |journal=Journal of Applied Crystallography |volume=3 |issue=6 |pages=466–485 |doi=10.1107/S0021889870006726 |bibcode=1970JApCr...3..466T }}</ref><ref>{{Citation |last1=Maitland |first1=Tim |title=Backscattering Detector and EBSD in Nanomaterials Characterization |date=2007 |work=Scanning Microscopy for Nanotechnology: Techniques and Applications |pages=41–75 |editor-last=Zhou |editor-first=Weilie |place=New York, New York |publisher=Springer |doi=10.1007/978-0-387-39620-0_2 |isbn=978-0-387-39620-0 |last2=Sitzman |first2=Scott |editor2-last=Wang |editor2-first=Zhong Lin}}</ref>
The systematically arranged Kikuchi bands, which have a range of intensity along their width, intersect around the centre of the regions of interest (ROI), describing the probed volume crystallography.<ref>{{Cite journal |date=1954|title=High-angle Kikuchi patterns |journal=Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences |volume=221 |issue=1145 |pages=224–242 |doi=10.1098/rspa.1954.0017 |bibcode=1954RSPSA.221..224A |last1=Alam |first1=M. N. |last2=Blackman |first2=M. |last3=Pashley |first3=D. W. |s2cid=97131764 }}</ref> These bands and their intersections form what is known as Kikuchi patterns or electron backscatter patterns (EBSPs). To improve contrast, the patterns’ background is corrected by removing anisotropic/inelastic scattering using static background correction or dynamic background correction.<ref>{{Cite journal |last1=Dingley |first1=D J |last2=Wright |first2=S I |last3=Nowell |first3=M M |date=August 2005 |title=Dynamic Background Correction of Electron Backscatter Diffraction Patterns |journal=Microscopy and Microanalysis |volume=11 |issue=S02 |doi=10.1017/S1431927605506676 |s2cid=137658758 |doi-access=free }}</ref>
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The diffraction pattern is pre-processed to remove noise, correct for detector distortions, and normalise the intensity. Then, the pre-processed diffraction pattern is compared to a library of reference patterns for the material being studied. The reference patterns are generated based on the material's known crystal structure and the crystal lattice's orientation. The orientation of the crystal lattice that would generate the best match to the measured pattern is determined using a variety of algorithms. There are three leading methods of indexing that are performed by most commercial EBSD software: triplet voting;<ref>{{Cite journal |last1=Wright |first1=Stuart I. |last2=Zhao |first2=Jun-Wu |last3=Adams |first3=Brent L. |date=1991 |title=Automated Determination of Lattice Orientation From Electron Backscattered Kikuchi Diffraction Patterns |journal=Texture, Stress, and Microstructure |volume=13 |issue=2–3 |pages=123–131 |doi=10.1155/TSM.13.123 |doi-access=free}}</ref><ref>{{Cite journal |last1=Wright |first1=Stuart I. |last2=Adams |first2=Brent L. |last3=Kunze |first3=Karsten |date=1993|title=Application of a new automatic lattice orientation measurement technique to polycrystalline aluminum |journal=Materials Science and Engineering: A |volume=160 |issue=2 |pages=229–240 |doi=10.1016/0921-5093(93)90452-K }}</ref> minimising the 'fit' between the experimental pattern and a computationally determined orientation,<ref>{{Cite journal |last=Lassen |first=Niels Chr. Krieger |date=1992 |title=Automatic crystal orientation determination from EBSPs |journal=Micron and Microscopica Acta |volume=23 |issue=1 |pages=191–192 |doi=10.1016/0739-6260(92)90133-X }}</ref><ref>{{Cite journal |last1=Krieger Lassen |first1=N.C. |last2=Juul Jensen |first2=Dorte |last3=Condradsen |first3=K. |date=1994 |title=Automatic Recognition of Deformed and Recrystallized Regions in Partly Recrystallized Samples Using Electron Back Scattering Patterns |journal=Materials Science Forum |volume=157–162 |pages=149–158 |doi=10.4028/www.scientific.net/msf.157-162.149 |s2cid=137129038}}</ref> and or/and neighbour pattern averaging and re-indexing, NPAR<ref>{{Cite journal |last1=Wright |first1=Stuart I. |last2=Nowell |first2=Matthew M. |last3=Lindeman |first3=Scott P. |last4=Camus |first4=Patrick P. |last5=De Graef |first5=Marc |last6=Jackson |first6=Michael A. |date=2015|title=Introduction and comparison of new EBSD post-processing methodologies |journal=Ultramicroscopy |volume=159 |pages=81–94 |doi=10.1016/j.ultramic.2015.08.001 |pmid=26342553 |doi-access=free }}</ref>). Indexing then give a unique solution to the single crystal orientation that is related to the other crystal orientations within the field-of-view.<ref>{{cite journal |last1=Randle |first1=Valerie |date= 2009 |title=Electron backscatter diffraction: Strategies for reliable data acquisition and processing |journal=Materials Characterization |volume=60 |issue=9 |pages=913–922 |doi=10.1016/j.matchar.2009.05.011}}</ref><ref name=":14">{{Cite thesis |last=Lassen |first=Niels Christian Krieger |title=Automated Determination of Crystal Orientations from Electron Backscattering Patterns |date=1994 |degree=PhD |publisher=The Technical University of Denmark |url=http://www.ebsd.info/pdf/PhD_KriegerLassen.pdf |archive-date=2022-03-08 |archive-url=https://web.archive.org/web/20220308024650/http://www.ebsd.info/pdf/PhD_KriegerLassen.pdf |url-status=live}}</ref>
Triplet voting involves identifying multiple 'triplets' associated with different solutions to the crystal orientation; each crystal orientation determined from each triplet receives one vote. Should four bands identify the same crystal orientation, then four ([[Combination|four choose three]], i.e. <math>C(4,3)</math>) votes will be cast for that particular solution. Thus the candidate orientation with the highest number of votes will be the most likely solution to the underlying crystal orientation present. The number of votes for the solution chosen compared to the total number of votes describes the confidence in the underlying solution. Care must be taken in interpreting this 'confidence index' as some pseudo-symmetric orientations may result in low confidence for one candidate solution vs another.<ref>{{Cite journal |journal=Microscopy and Microanalysis |doi=10.1017/s143192761501096x |title=Addressing Pseudo-Symmetric Misindexing in EBSD Analysis of γ-TiAl with High Accuracy Band Detection |year=2015 |last1=Sitzman |first1=Scott |last2=Schmidt |first2=Niels-Henrik |last3=Palomares-Garcia |first3=Alberto |last4=Munoz-Moreno |first4=Rocio |last5=Goulden |first5=Jenny |volume=21 |issue=S3 |pages=2037–2038 |bibcode=2015MiMic..21S2037S |s2cid=51964340 |doi-access=free }}</ref><ref>{{Cite journal |last1=Lenthe |first1=W. |last2=Singh |first2=S. |last3=De Graef |first3=M. |date=2019 |title=Prediction of potential pseudo-symmetry issues in the indexing of electron backscatter diffraction patterns |url=https://journals.iucr.org/j/issues/2019/05/00/po5152/ |journal=Journal of Applied Crystallography |volume=52 |issue=5 |pages=1157–1168 |doi=10.1107/S1600576719011233 |bibcode=2019JApCr..52.1157L |osti=1575873 |s2cid=204108200 }}</ref><ref>{{Citation |last1=Dingley |first1=David J. |title=Phase Identification Through Symmetry Determination in EBSD Patterns |date=2009 |work=Electron Backscatter Diffraction in Materials Science |pages=97–107 |editor-last=Schwartz |editor-first=Adam J. |place=Boston, MA |publisher=Springer US |doi=10.1007/978-0-387-88136-2_7 |isbn=978-0-387-88136-2 |last2=Wright |first2=S.I. |editor2-last=Kumar |editor2-first=Mukul |editor3-last=Adams |editor3-first=Brent L. |editor4-last=Field |editor4-first=David P. }}</ref> Minimising the fit involves starting with all possible orientations for a triplet. More bands are included, which reduces the number of candidate orientations. As the number of bands increases, the number of possible orientations converges ultimately to one solution. The 'fit' between the measured orientation and the captured pattern can be determined.<ref name=":14" />
Overall, indexing diffraction patterns in EBSD involves a complex set of algorithms and calculations, but is essential for determining the crystallographic structure and orientation of materials at a high spatial resolution. The indexing process is continually evolving, with new algorithms and techniques being developed to improve the accuracy and speed of the process. Afterwards, a confidence index is calculated to determine the quality of the indexing result. The confidence index is based on the match quality between the measured and reference patterns. In addition, it considers factors such as noise level, detector resolution, and sample quality.<ref name="EBSDSpringer2009" />
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=== Pattern centre ===
To relate the orientation of a crystal, much like in [[X-ray diffraction]] (XRD), the geometry of the system must be known. In particular, the pattern centre describes the distance of the interaction volume to the detector and the ___location of the nearest point between the phosphor and the sample, on the phosphor screen. Early work used a single crystal of known orientation being inserted into the SEM chamber, and a particular feature of the EBSP was known to correspond to the pattern centre. Later developments involved exploiting various geometric relationships between the generation of an EBSP and the chamber geometry (shadow casting and phosphor movement).<ref name=":1">{{Cite journal |last1=Britton |first1=T. B. |last2=Tong |first2=V. S. |last3=Hickey |first3=J. |last4=Foden |first4=A. |last5=Wilkinson |first5=A. J. |date=2018 |title=AstroEBSD: exploring new space in pattern indexing with methods launched from an astronomical approach |url=https://journals.iucr.org/j/issues/2018/06/00/nb5225/ |journal=Journal of Applied Crystallography |volume=51 |issue=6 |pages=1525–1534 |doi=10.1107/S1600576718010373 |arxiv=1804.02602 |bibcode=2018JApCr..51.1525B |s2cid=51687153 }}</ref><ref name=":14" />
Unfortunately, each of these methods is cumbersome and can be prone to some systematic errors for a general operator. Typically they cannot be easily used in modern SEMs with multiple designated uses. Thus, most commercial EBSD systems use the indexing algorithm combined with an iterative movement of crystal orientation and suggested pattern centre ___location. Minimising the fit between bands located within experimental patterns and those in look-up tables tends to converge on the pattern centre ___location to an accuracy of ~0.5–1% of the pattern width.<ref name=":15" /><ref name=":0" />
The recent development of AstroEBSD<ref>{{Cite journal |last1=Britton |first1=Thomas Benjamin |last2=Tong |first2=Vivian S. |last3=Hickey |first3=Jim |last4=Foden |first4=Alex |last5=Wilkinson |first5=Angus J. |date=2018 |title=AstroEBSD : exploring new space in pattern indexing with methods launched from an astronomical approach|journal=Journal of Applied Crystallography |volume=51 |issue=6 |pages=1525–1534 |doi=10.1107/S1600576718010373 |arxiv=1804.02602 |bibcode=2018JApCr..51.1525B |s2cid=51687153 }}</ref> and PCGlobal,<ref>{{Cite journal |last1=Pang |first1=Edward L. |last2=Larsen |first2=Peter M. |last3=Schuh |first3=Christopher A. |date=2020 |title=Global optimization for accurate determination of EBSD pattern centers |journal=Ultramicroscopy |volume=209 |pages=112876 |doi=10.1016/j.ultramic.2019.112876 |pmid=31707232 |s2cid=201651309|arxiv=1908.10692 }}</ref> open-source [[MATLAB]] codes, increased the precision of determining the pattern centre (PC) and – consequently – elastic strains<ref>{{Cite journal |last1=Tanaka |first1=Tomohito |last2=Wilkinson |first2=Angus J. |date=2019-07-01 |title=Pattern matching analysis of electron backscatter diffraction patterns for pattern centre, crystal orientation and absolute elastic strain determination – accuracy and precision assessment |journal=Ultramicroscopy|volume=202 |pages=87–99 |doi=10.1016/j.ultramic.2019.04.006 |pmid=31005023 |arxiv=1904.06891 |s2cid=119294636 }}</ref> by using a pattern matching approach<ref>{{Cite journal |last1=Foden |first1=A. |last2=Collins |first2=D.M. |last3=Wilkinson |first3=A.J. |last4=Britton |first4=T.B. |date=2019 |title=Indexing electron backscatter diffraction patterns with a refined template matching approach |journal=Ultramicroscopy |volume=207 |pages=112845 |doi=10.1016/j.ultramic.2019.112845 |pmid=31586829 |arxiv=1807.11313 |s2cid=203307560 }}</ref> which simulates the pattern using EMSoft.<ref>{{Cite journal |last1=Jackson |first1=M. A. |last2=Pascal |first2=E. |last3=De Graef |first3=M. |date=2019 |title=Dictionary Indexing of Electron Back-Scatter Diffraction Patterns: a Hands-On Tutorial |journal=Integrating Materials and Manufacturing Innovation |volume=8 |issue=2 |pages=226–246 |doi=10.1007/s40192-019-00137-4 |s2cid=182073071}}</ref>
=== EBSD mapping ===
[[File:EBSD orientation map of ferrous lath martensite.jpg|thumb|A map of indexed EBSD orientations for a ferrous [[martensite]] with high-angle (>10°) boundaries|alt=A. EBSD map of ferrous martensite with high-angle (>10°) boundaries hilighted. Colour scheme follows the typic IPF for BCC crystal plotted in Z-direction]]
The indexing results are used to generate a map of the crystallographic orientation at each point on the surface being studied. Thus, scanning the electron beam in a prescribed fashion (typically in a square or hexagonal grid, correcting for the image foreshortening due to the sample tilt) results in many rich microstructural maps.<ref>{{Cite journal |last1=Dingley |first1=D. J. |last2=Randle |first2=V. |date=1992 |title=Microtexture determination by electron back-scatter diffraction |journal=Journal of Materials Science |volume=27 |issue=17 |pages=4545–4566 |doi=10.1007/BF01165988 |bibcode=1992JMatS..27.4545D |s2cid=137281137 }}</ref><ref>{{Cite journal |last=Adams |first=Brent L. |date=1997 |title=Orientation imaging microscopy: Emerging and future applications|journal=Ultramicroscopy |series=Frontiers in Electron Microscopy in Materials Science |volume=67 |issue=1 |pages=11–17 |doi=10.1016/S0304-3991(96)00103-9 }}</ref> These maps can spatially describe the crystal orientation of the material being interrogated and can be used to examine microtexture and sample morphology. Some maps describe grain orientation, boundary, and diffraction pattern (image) quality. Various statistical tools can measure the average [[misorientation]], grain size, and crystallographic texture. From this dataset, numerous maps, charts and plots can be generated.<ref>{{Cite journal |last1=Hielscher |first1=Ralf |last2=Bartel |first2=Felix |last3=Britton |first3=Thomas Benjamin |date= 2019 |title=Gazing at crystal balls: Electron backscatter diffraction pattern analysis and cross-correlation on the sphere |journal=Ultramicroscopy |volume=207 |pages=112836 |doi=10.1016/j.ultramic.2019.112836 |pmid=31539865 |arxiv=1810.03211 |s2cid=202711517}}</ref><ref>{{Cite journal |last1=Hielscher |first1=R. |last2=Silbermann |first2=C. B. |last3=Schmidl |first3=E. |last4=Ihlemann |first4=Joern |date=2019 |title=Denoising of crystal orientation maps |journal=Journal of Applied Crystallography |volume=52 |issue=5 |pages=984–996 |doi=10.1107/s1600576719009075 |bibcode=2019JApCr..52..984H |s2cid=202068671 }}</ref><ref name=":3" /> The orientation data can be visualised using a variety of techniques, including colour-coding, contour lines, and pole figures.<ref name=":23">{{cite book |last1=Randle |first1=Valerie |title=Introduction to texture analysis: macrotexture, microtexture and orientation mapping |last2=Engler |first2=Olaf |date=2000 |publisher=[[CRC Press]] |isbn=978-9056992248 |edition=Digital printing 2003 |___location=Boca Raton}}</ref>
Microscope misalignment, image shift, scan distortion that increases with decreasing magnification, roughness and contamination of the specimen surface, boundary indexing failure and detector quality can lead to uncertainties in determining the crystal orientation.<ref name=":2">{{Cite journal |last=Prior |date= 1999 |title=Problems in determining the misorientation axes, for small angular misorientations, using electron backscatter diffraction in the SEM |journal=Journal of Microscopy |volume=195 |issue=3 |pages=217–225 |doi=10.1046/j.1365-2818.1999.00572.x |pmid=10460687 |s2cid=10144078}}</ref> The EBSD [[signal-to-noise ratio]] depends on the material and decreases at excessive acquisition speed and beam current, thereby affecting the angular resolution of the measurement.<ref name=":2" />
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=== Earlier trials ===
The change and degradation in electron backscatter patterns (EBSPs) provide information about the diffracting volume. Pattern degradation (i.e., diffuse quality) can be used to assess the level of plasticity through the pattern/image quality (IQ),<ref>{{Cite journal |last1=Lassen |first1=N. C. Krieger |last2=Jensen |first2=Dorte Juul |last3=Condradsen |first3=K. |date=1994 |title=Automatic Recognition of Deformed and Recrystallized Regions in Partly Recrystallized Samples Using Electron Back Scattering Patterns |url=https://www.scientific.net/MSF.157-162.149 |journal=Materials Science Forum |volume=157–162 |pages=149–158 |doi=10.4028/www.scientific.net/MSF.157-162.149 |s2cid=137129038 |access-date=2 March 2023 |archive-date=2 March 2023 |archive-url=https://web.archive.org/web/20230302135533/https://www.scientific.net/MSF.157-162.149 |url-status=live }}</ref> where IQ is calculated from the sum of the peaks detected when using the conventional Hough transform. [[Angus Wilkinson|Wilkinson]]<ref>{{Cite journal |last=Wilkinson |first=A. J. |date=1997-01-01 |title=Methods for determining elastic strains from electron backscatter diffraction and electron channelling patterns |journal=Materials Science and Technology |volume=13 |issue=1 |pages=79–84 |doi=10.1179/mst.1997.13.1.79 |bibcode=1997MatST..13...79W}}</ref> first used the changes in high-order Kikuchi line positions to determine the elastic strains, albeit with low [[Accuracy and precision|precision]]{{NoteTag|Throughout this page, the terms ‘error’, and ‘precision’ are used as defined in the [[International Bureau of Weights and Measures]] (BIPM) [https://www.bipm.org/documents/20126/2071204/JCGM_100_2008_E.pdf/cb0ef43f-baa5-11cf-3f85-4dcd86f77bd6 guide to measurement uncertainty]. In practice, ‘error’, ‘accuracy’ and ‘uncertainty’, as well as ‘true value’ and ‘best guess’, are synonymous. Precision is the variance (or standard deviation) between all estimated quantities. Bias is the difference between the average of measured values and an independently measured ‘best guess’. Accuracy is then the combination of bias and precision.<ref name=":10" />}} (0.3% to 1%); however, this approach cannot be used for characterising residual elastic strain in metals as the elastic strain at the yield point is usually around 0.2%. Measuring strain by tracking the change in the higher-order Kikuchi lines is practical when the strain is small, as the band position is sensitive to changes in lattice parameters.<ref name=":24">{{Cite journal |last1=Zhu |first1=Chaoyi |last2=De Graef |first2=Marc |date=2020 |title=EBSD pattern simulations for an interaction volume containing lattice defects |journal=Ultramicroscopy |volume=218 |pages=113088 |doi=10.1016/j.ultramic.2020.113088 |pmid=32784084 |s2cid=221123906 |doi-access=free }}</ref> In the early 1990s, Troost ''et al.''<ref>{{Cite journal |last1=Troost |first1=K. Z. |last2=van der Sluis |first2=P. |last3=Gravesteijn |first3=D. J. |date=1993 |title=Microscale
=== High-resolution electron backscatter diffraction (HR-EBSD)===
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The local lattice distortion at the EBSP<sub>0</sub> influences the resultant HR-EBSD map, e.g., a reference pattern deformed in tension will directly reduce the HR-EBSD map tensile strain magnitude while indirectly influencing the other component magnitude and the strain's spatial distribution. Furthermore, the choice of EBSP<sub>0</sub> slightly affects the GND density distribution and magnitude, and choosing a reference pattern with a higher GND density reduces the cross-correlation quality, changes the spatial distribution and induces more errors than choosing a reference pattern with high lattice distortion. Additionally, there is no apparent connection between EBSP<sub>0</sub>’s IQ and EBSP<sub>0</sub>'s local lattice distortion.<ref name=":10" />
The use of simulated reference patterns for absolute strain measurement is still an active area of research<ref name=":22">{{Cite journal |last1=Winkelmann |first1=Aimo |last2=Trager-Cowan |first2=Carol |last3=Sweeney |first3=Francis |last4=Day |first4=Austin P. |last5=Parbrook |first5=Peter |date=2007 |title=Many-beam dynamical simulation of electron backscatter diffraction patterns |journal=Ultramicroscopy |volume=107 |issue=4 |pages=414–421 |doi=10.1016/j.ultramic.2006.10.006 |pmid=17126489}}</ref><ref>{{Cite journal |last1=Kacher |first1=Josh |last2=Landon |first2=Colin |last3=Adams |first3=Brent L. |last4=Fullwood |first4=David |date=2009-08-01 |title=Bragg's Law diffraction simulations for electron backscatter diffraction analysis |journal=Ultramicroscopy |volume=109 |issue=9 |pages=1148–1156 |doi=10.1016/j.ultramic.2009.04.007 |pmid=19520512}}</ref><ref>{{Cite journal |last1=Winkelmann |first1=A |last2=Nolze |first2=G |last3=Vos |first3=M |last4=Salvat-Pujol |first4=F |last5=Werner |first5=W S M |date=2016 |title=Physics-based simulation models for EBSD: advances and challenges |journal=IOP Conference Series: Materials Science and Engineering |volume=109 |issue=1 |pages=012018 |doi=10.1088/1757-899x/109/1/012018 |arxiv=1505.07982 |bibcode=2016MS&E..109a2018W |s2cid=38586851}}</ref><ref>{{Cite journal |last1=Alkorta |first1=Jon |last2=Marteleur |first2=Matthieu |last3=Jacques |first3=Pascal J. |date=2017 |title=Improved simulation based HR-EBSD procedure using image gradient based DIC techniques |journal=Ultramicroscopy |volume=182 |pages=17–27 |doi=10.1016/j.ultramic.2017.06.015 |pmid=28644960 }}</ref><ref>{{Cite journal |last1=Winkelmann |first1=Aimo |last2=Nolze |first2=Gert |last3=Cios |first3=Grzegorz |last4=Tokarski |first4=Tomasz |last5=Bała |first5=Piotr |last6=Hourahine |first6=Ben |last7=
In addition, GND density estimation is nominally insensitive to (or negligibly dependent upon<ref>{{Cite journal |last1=Jiang |first1=J. |last2=Britton |first2=T. B. |last3=Wilkinson |first3=A. J. |date=2013-11-01 |title=Evolution of dislocation density distributions in copper during tensile deformation |journal=Acta Materialia |volume=61 |issue=19 |pages=7227–7239 |doi=10.1016/j.actamat.2013.08.027 |bibcode=2013AcMat..61.7227J |doi-access=free }}</ref><ref>{{Cite journal |last1=Britton |first1=T B |last2=Hickey |first2=J L R |date= 2018 |title=Understanding deformation with high angular resolution electron backscatter diffraction (HR-EBSD) |journal=IOP Conference Series: Materials Science and Engineering |volume=304 |issue=1 |pages=012003 |doi=10.1088/1757-899x/304/1/012003 |bibcode=2018MS&E..304a2003B |s2cid=54529072 |arxiv=1710.00728 }}</ref>) EBSP<sub>0</sub> choice, as only neighbour point-to-point differences in the lattice rotation maps are used for GND density calculation.<ref>{{Cite journal |last1=Kalácska |first1=Szilvia |last2=Dankházi |first2=Zoltán |last3=Zilahi |first3=Gyula |last4=Maeder |first4=Xavier |last5=Michler |first5=Johann |last6=Ispánovity |first6=Péter Dusán |last7=Groma |first7=István |date=2020 |title=Investigation of geometrically necessary dislocation structures in compressed Cu micropillars by 3-dimensional HR-EBSD |journal=Materials Science and Engineering: A |volume=770 |pages=138499 |doi=10.1016/j.msea.2019.138499 |s2cid=189928469 |url=https://bib-pubdb1.desy.de/record/426593 |access-date=20 March 2023 |archive-date=17 July 2020 |archive-url=https://web.archive.org/web/20200717095713/http://bib-pubdb1.desy.de/record/426593 |url-status=live |arxiv=1906.06980 }}</ref><ref>{{Cite journal |last1=Wallis |first1=David |last2=Hansen |first2=Lars N. |last3=Britton |first3=T. Ben |last4=Wilkinson |first4=Angus J. |date= 2017 |title=Dislocation Interactions in Olivine Revealed by HR-EBSD: Dislocation Interactions in Olivine |journal=Journal of Geophysical Research: Solid Earth |volume=122 |issue=10 |pages=7659–7678 |doi=10.1002/2017JB014513|hdl=10044/1/50615 |s2cid=134570945 |hdl-access=free }}</ref> However, this assumes that the absolute lattice distortion of EBSP<sub>0</sub> only changes the relative lattice rotation map components by a constant value which vanishes during derivative operations, i.e., lattice distortion distribution is insensitive to EBSP<sub>0</sub> choice.<ref name=":9" /><ref name=":10">{{Cite journal |last1=Koko |first1=Abdalrhaman |last2=Tong |first2=Vivian |last3=Wilkinson |first3=Angus J. |author-link3=Angus Wilkinson |last4=Marrow |first4=T. James |author-link4=James Marrow |date=2023 |title=An iterative method for reference pattern selection in high-resolution electron backscatter diffraction (HR-EBSD) |journal=Ultramicroscopy |volume=248 |pages=113705 |arxiv=2206.10242 |doi=10.1016/j.ultramic.2023.113705 |pmid=36871367 |s2cid=249889699}}{{Creative Commons text attribution notice|cc=by4|from this source=yes}}</ref>
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== Applications ==
EBSD is used in a wide range of applications, including materials science and engineering,<ref name=":20" /> geology,<ref>{{Citation |last1=Prior |first1=David J. |title=EBSD in the Earth Sciences: Applications, Common Practice, and Challenges |date=2009 |work=Electron Backscatter Diffraction in Materials Science |pages=345–360 |place=Boston, MA |publisher=Springer US |isbn=978-0-387-88135-5 |last2=Mariani |first2=Elisabetta |last3=Wheeler |first3=John|doi=10.1007/978-0-387-88136-2_26 }}</ref> and biological research.<ref>{{Cite journal |last1=Choi |first1=Seung |last2=Han |first2=Seokyoung |last3=Lee |first3=
=== Scattered electron imaging ===
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| caption2 = Far-field image of [[475 °C embrittlement|475 °C embrittled duplex stainless steel]] with the virtual forward-scatter detector (VFSD) positioned at 38 mm from the sample
}}
EBSD detectors can have forward scattered electron [[diode]]s (FSD) at the bottom, in the middle (MSD) and at the top of the detector. Forward-scattered electron (FSE) imaging involves collecting electrons scattered at small angles from the surface of a sample, which provides information about the surface topography and composition.<ref name=":34" /><ref name=":46">{{Cite journal |last1=Schwarzer |first1=Robert A |last2=Hjelen |first2=Jarle |date=2015-01-09 |title=Backscattered Electron Imaging with an EBSD Detector
The FSE signal is typically collected simultaneously with the BSE signal in EBSD analysis. The BSE signal is sensitive to the average atomic number of the sample, and is used to generate an image of the surface topography and composition. The FSE signal is superimposed on the BSE image to provide information about the crystallographic orientation.<ref name=":37" /><ref name=":34">{{Cite journal |last1=Wright |first1=Stuart I. |last2=Nowell |first2=Matthew M. |last3=de Kloe |first3=René |last4=Camus |first4=Patrick |last5=Rampton |first5=Travis |date=2015 |title=Electron imaging with an EBSD detector |journal=Ultramicroscopy |volume=148 |pages=132–145 |doi=10.1016/j.ultramic.2014.10.002 |pmid=25461590|doi-access=free }}</ref>
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=== Integrated EBSD/EDS mapping ===
When simultaneous EDS/EBSD collection can be achieved, the capabilities of both techniques can be enhanced.<ref>{{Cite news |date=2015 |title=Discriminating Phases with Similar Crystal Structures Using Electron Backscatter Diffraction (EBSD) and Energy Dispersive X-Ray Spectrometry (EDS) |url=https://www.azonano.com/article.aspx?ArticleID=3955 |url-status=live |archive-url=https://web.archive.org/web/20230302142457/https://www.azonano.com/article.aspx?ArticleID=3955 |archive-date=2023-03-02 |website=AZoNano.com }}</ref> There are applications where sample chemistry or phase cannot be differentiated via EDS alone because of similar composition, and structure cannot be solved with EBSD alone because of ambiguous structure solutions.<ref>{{Cite journal |last1=Nolze |first1=G. |last2=Geist |first2=V. |last3=Neumann |first3=R. Saliwan |last4=Buchheim |first4=M. |date=2005|title=Investigation of orientation relationships by EBSD and EDS on the example of the Watson iron meteorite |journal=Crystal Research and Technology |volume=40 |issue=8 |pages=791–804 |doi=10.1002/crat.200410434|s2cid=96785527|doi-access=free |bibcode=2005CryRT..40..791N }}</ref><ref>{{Cite web |date=2022-11-29 |title=Uncovering the tiny defects that make materials fail |url=https://physicsworld.com/uncovering-the-tiny-defects-that-make-materials-fail/ |url-status=live |archive-url=https://web.archive.org/web/20230303225536/https://physicsworld.com/a/uncovering-the-tiny-defects-that-make-materials-fail/ |archive-date=2023-03-03 |website=Physics World}}</ref> To accomplish integrated mapping, the analysis area is scanned, and at each point, Hough peaks and EDS region-of-interest counts are stored. Positions of phases are determined in [[X-ray crystallography|X-ray]] maps, and each element's measured EDS intensities are given in charts. The chemical intensity ranges are set for each phase to select the grains.<ref>{{Cite journal |last1=Kell |first1=J. |last2=Tyrer |first2=J. R. |last3=Higginson |first3=R. L. |last4=Thomson |first4=R. C. |date=2005 |title=Microstructural characterization of autogenous laser welds on 316L stainless steel using EBSD and EDS |journal=Journal of Microscopy |volume=217 |issue=2 |pages=167–173 |doi=10.1111/j.1365-2818.2005.01447.x|pmid=15683414 |s2cid=12285114}}</ref> All patterns are then re-indexed off-line. The recorded chemistry determines which phase/crystal-structure file is used to index each point. Each pattern is indexed by only one phase, and maps displaying distinguished phases are generated. The interaction volumes for EDS and EBSD are significantly different (on the order of [[micrometre]]s compared to tens of [[nanometres]]), and the shape of these volumes using a highly tilted sample may have implications on algorithms for phase discrimination.<ref name=":21" /><ref>{{Cite journal |last1=West |first1=G.D. |last2=Thomson |first2=R.C. |date=2009 |title=Combined EBSD/EDS tomography in a dual-beam FIB/FEG-SEM |journal=Journal of Microscopy |volume=233 |issue=3 |pages=442–450 |doi=10.1111/j.1365-2818.2009.03138.x |pmid=19250465 |s2cid=42955621}}</ref>
EBSD, when used together with other in-SEM techniques such as [[cathodoluminescence]] (CL),<ref>{{Cite journal |last1=Moser |first1=D. E. |last2=Cupelli |first2=C. L. |last3=Barker |first3=I. R. |last4=Flowers |first4=R. M. |last5=Bowman |first5=J. R. |last6=Wooden |first6=J. |last7=Hart |first7=J.R. |date=2011 |editor-last=Davis |editor-first=William J. |title=New zircon shock phenomena and their use for dating and reconstruction of large impact structures revealed by electron nanobeam (EBSD, CL, EDS) and isotopic U–Pb and (U–Th)/He analysis of the Vredefort domeThis article is one of a series of papers published in this Special Issue on the theme of Geochronology in honour of Tom Krogh|journal=Canadian Journal of Earth Sciences |volume=48 |issue=2 |pages=117–139 |bibcode=2011CaJES..48..117D |doi=10.1139/E11-011 }}</ref> [[wavelength dispersive X-ray spectroscopy]] (WDS)<ref>{{Cite journal |last1=Laigo |first1=J. |last2=Christien |first2=F. |last3=Le Gall |first3=R. |last4=Tancret |first4=F. |last5=Furtado |first5=J. |date=2008 |title=SEM, EDS, EPMA-WDS and EBSD characterization of carbides in HP type heat resistant alloys |journal=Materials Characterization |volume=59 |issue=11 |pages=1580–1586 |doi=10.1016/j.matchar.2008.02.001 }}</ref> and/or EDS can provide a deeper insight into the specimen's properties and enhance phase identification.<ref>{{Cite web |date=2023-01-18 |title=Microscale Analysis of Lithium-Containing Compounds and Alloys |url=https://www.azom.com/article.aspx?ArticleID=22349 |url-status=live |archive-url=https://web.archive.org/web/20230217121105/https://www.azom.com/article.aspx?ArticleID=22349 |archive-date=2023-02-17 |website=AZoM.com }}</ref><ref>{{Cite journal |last1=Wisniewski |first1=Wolfgang |last2=Švančárek |first2=Peter |last3=Prnová |first3=Anna |last4=Parchovianský |first4=Milan |last5=Galusek |first5=Dušan |date=2020|title=Y<sub>2</sub>O<sub>3</sub>–Al<sub>2</sub>O<sub>3</sub> microsphere crystallization analyzed by electron backscatter diffraction (EBSD) |journal=Scientific Reports |volume=10 |issue=1 |pages=11122 |bibcode=2020NatSR..1011122W |doi=10.1038/s41598-020-67816-7 |pmc=7338460 |pmid=32632218}}</ref> For example, the minerals [[calcite]] ([[limestone]]) and [[aragonite]] ([[Animal shell|shell]]) have the same chemical composition – [[calcium carbonate]] (CaCO<sub>3</sub>) therefore EDS/WDS cannot tell them apart, but they have different microcrystalline structures so EBSD can differentiate between them.<ref>{{Cite journal |last1=Ohfuji |first1=Hiroaki |last2=Yamamoto |first2=Masashi |date=2015 |title=EDS quantification of light elements using osmium surface coating |journal=Journal of Mineralogical and Petrological Sciences |volume=110 |issue=4 |pages=189–195 |bibcode=2015JMPeS.110..189O |doi=10.2465/jmps.141126 |s2cid=93672390|doi-access=free }}</ref><ref>{{Citation |last=Frahm |first=Ellery |title=Scanning Electron Microscopy (SEM): Applications in Archaeology |date=2014 |encyclopedia=Encyclopedia of Global Archaeology |pages=6487–6495 |place=New York, New York |publisher=Springer New York |doi=10.1007/978-1-4419-0465-2_341 |isbn=978-1-4419-0426-3 }}</ref>
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