Individual grain orientation measurement in the SEM
from backscatter Kikuchi patterns (BKP)

History of BKD and "Automated EBSD"  
 

1928

Shoji Nishikawa and Seishi Kikuchi
The Diffraction of Cathode Rays by Calcite.
Proc. Imperial Academy (of Japan) 4 (1928) 475-477
The first EBSP was published by S. Nishikawa and S. Kikuchi in 1928. They directed a beam of 50 keV electrons from a gas discharge on a cleavage face of calcite at a grazing incidence of 6°. Diffraction patterns were recorded on photographic plates placed 6.4 cm behind the crystal, normal to the primary beam. The patterns consisted of pairs of parallel black and white lines, and in some cases contained diffraction spots in addition. They were similar to those patterns obtained by S. Kikuchi in a transmission experiment on mica foils (first published in the same volume).
When the photographic plates were placed in front of the specimen (parallel with the primary beam, as nowadays in modern "EBSD" setups), the same type of pattern was observed as well "which must have been produced by the electrons deflected through an angle greater than 90° ". Since transmission and backscatter patterns were quite similiar, they have been likewise interpreted and indexed. The relative intensities of high-order reflections were compared with those of X-ray diffraction. Cleavage faces of mica, topaz, zincblende and a natural face of quartz were also tried and it was found that they give similar backscatter patterns.


The authors called this new type of pattern "P-pattern" (= "black and white lines in pairs due to multiple scattering and selective reflection") or "pattern of the fourth kind". They have later been named "transmission Kikuchi patterns" respectively "reflection Kikuchi patterns" or "backscatter Kikuchi patterns".
The low quality of the first BKP may be caused by specimen contamination due to the poor vacuum facilities at that time.


Seishi Kikuchi and Shigeo Nakagawa concentrated their studies on the deviation of the lines from the exact Bragg position due to anomalous dispersion of crossing lines and the effect of the refractive index of the lattice on fast electrons.
S. Kikuchi and Sh. Nakagawa
On the reflection of cathode rays from single crystal surfaces. (paper in German)
Sc. Pap.
Inst. Phys. Chem. Res. 21 (1933) 80-91
S. Kikuchi and Sh. Nakagawa
The anomalous reflection of fast electrons from single crystal surfaces. (paper in German)
Sc. Pap. Inst. Phys. Chem. Res. 21 (1933) 256-265

Already in 1928, Seishi Kikuchi grew fond of atomic physics. He published an investigation on the mode of disintegration of Radium (J.J.Phys. 4(1928) 143.), met Werner von Heisenberg on his visit to Japan, and joined for some time Heisenberg's team at the university of Leipzig (Germany). Back in Japan, starting in 1934 he installed a 600 kV Cockroft-Walton high-voltage generator, the most powerful at that time, and a charged particle accelerator at the (now) Osaka University Physical Science Department. Seishi Kikuchi is known as an outstanding Japanese nuclear physicist.
 

1932/33

K. Shinohara:
Diffraction of cathode rays by single crystals. Part III.
Sc. Pap. Inst. Phys. Chem. Res. 20 (1932/33) 39-51
Kikuchi envelops are reported in backscatter Kikuchi patterns from cleaved calcspar (calcite, CaCO
3) at 44 keV.
 

1933

R. von Meibom and E. Rupp
Wide-angle electron diffraction. (paper in German)
Z. Physik 82 (1933) 690-696
In backscatter diffraction of fast electrons from rocksalt, sylvine, fluorspar, diamond, calcspar and quartz crystals, dark bands (on the photographic negative) have been reported that are bordered on both sides by (Kikuchi) lines. The bands were visible through acceptance angles up to 160°. The angle of beam incidence was varied between 3° and 30°, the beam voltage from 10 kV to 40 kV. The band width is proportional to
l/d. Intensity profiles across two typical bands are sketched. Experiment showed that the bands are formed by backscattered electrons of virtually the same energy as the primary beam energy. The center lines of the bands - now called Kikuchi bands - have been indexed as zone circles sectioning the cylindrical recording film.
 

 1937

H. Boersch
About bands in electron diffraction. (paper in German)
Physikalische Zeitschrift 38 (1937) 1000-1004
Boersch studied thoroughly - in addition to transmission - also backscatter Kikuchi patterns (at 20 kV, about 5° of incidence and up to 162° of acceptance angle) obtained from cleaved, polished respectively etched NaCl, KCl, PbS, CaCO
3, CaF2, quartz, mica, diamond, Cu and Fe surfaces.

BKP obtained from iron and fluorite

Backscatter Kikuchi patterns obtained from iron (left) and fluorspar (fluorite) (right, recorded on a cylindrical film) at 20 kV. 

He used flat photographic plates as well as a cylindrical specimen chamber with a cylindrical film to produce high-angle Kikuchi patterns. The angular range is considerably larger than that obtained before in the TEM and in present SEM appliances. The patterns are remarkably sharp and rich in detail. The widths of the bands was found, in agreement with Bragg's law, to be related to the energy of the incident beam and the interplanar lattice spacings.

Boersch has discussed the origin of Kikuchi lines, dark and bright bands and envelops taking von Laue's dynamical theory of electron diffraction into consideration.

G.I. Finch and H. Wilman
The study of surface structures by electron diffraction.
Ergebnisse der exakten Naturwissenschaften 16 (1937) 353-436

Several BKP from cleaved single crystals.

In this review a collection of excellent backscatter Kikuchi patterns form a variety of single crystal cleavage faces have been presented.
 

1947, 1948

K. Artmann
On the theory of Kikuchi envelops. (paper in German)
Zeitschrift fuer Physik 124 (1947) 80-104, 154-174; 125 (1948) 27-58, 298-335
The formation of Kikuchi envelops is treated without using the reciprocity law as well as in a rigorous wave-dynamical treatment based on the reciprocity law, a one dimensional and a three dimensional periodic crystal lattice. A good agreement of both features, surface lattice envelops and crystal lattice envelops, with experimental findings has been obtained.

(Remark: Kikuchi envelops can have a ring shape or a parabolic appearance. Perhaps due to the similarity with HOLZ rings of spots in transmission electron diffraction on thin foils, the ring shaped envelops are sometimes named "HOLZ lines" in recent publications even in the case of BKD. One should, however, bear in mind that Kikuchi envelops are definitively an effect of dynamical rather than kinematical diffraction. The Ewald construction is a very useful model for illustrating the formation of diffraction spots, but it is not applicable for BKD. In particular, there is no coherence between a primary beam and the diffracted beams.)

K. Artmann
On the theory of Kikuchi bands. (paper in German)
Zeitschrift fuer Physik 125 (1948) 225-249
The formation of Kikuchi patterns is treated by using the reciprocity law and solving the Schroedinger equation for bound electrons in the three dimensional crystal potential. This approach of  dynamical theory of electron diffraction leads to a good agreement of the intensity profile and location of Kikuchi bands with experimental results.


...... many publications have appeared since then, for example:
 

1954

M.N. Alam, M. Blackman and D.W. Pashley
High-angle Kikuchi patterns.
Proceedings of the Royal Society of London A 221 (1954) 224-242
A cylindrical specimen chamber and camera have been used to study the high-angle Kikuchi patterns obtained by reflexion of electrons, of energy 6 to 50 keV, from the cleavage surfaces of crystals with the sodium chloride structure. Angles of scattering ranging from 0 to 164° were covered. The relative intensity of the pattern at different scattering angles was measured using a photographic technique. The intensity distribution was found to become less steep as the energy of the incident electrons decreased. In photographs taken with a large value of the glancing angle of incidence, defect bands were found, starting near the shadow edge of the pattern; these changed to excess bands at higher angles of scattering.
The most striking feature of the results is the remarkable intensity and clarity at the highest scattering angles of the pattern produced by crystals such as lead sulphide and potassium iodide, the constituents of which have a relatively high elastic scattering cross-section. In marked contrast, a relatively low intensity and low clarity was found at these angles for lithium fluoride under the same experimental conditions. An investigation of the width of Kikuchi bands, visible over the whole available angular range, showed that the electrons forming these bands had the same energy as that of the incident electrons within the experimental error of 10%. A possible mechanism is discussed by means of which electrons can be diffused through large angles with high efficiency, relative to small angles, and with relatively little loss of energy.

1973

J.A. Venables, C.J. Harland
Video camera attached to the SEM. They have coined the new term "EBSP" (= Electron BackScatter Patterns) for backscatter Kikuchi patterns..

1987

D. Dingley & Link: 1st commercial system for the SEM
The user had to identify and locate 3 zone axes on the screen, then the program calculated the rotation matrix; feasible for cubic crystal symmetry.

1990

N.-H. Schmidt (Risų; HKL): commercial system ("Channel")
The user had to mark interactively 3 or more bands.

1992

N. Krieger Lassen, D. Juul Jensen, K. Conradsen
Automated indexing using the Hough transform and a butterfly mask.

1993

B.L. Adams, S.I. Wright
"OIM": mechanical stage scan; Burns algorithm, Hough transform.

1994

Niels Krieger Lassen (PhD Thesis at Risų and Univ. Lingby, Denmark)
Thorough investigation of the Hough transform for automated EBSD.

home

next