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Questions related from Gert Nolze
Known are the length in a triangle ABC of a tetrahedron ABCD, i.e., also all angles between A, B and C are known. The position of D is, however, unknown, but the angles between all edges to D,...
07 July 2019 3,121 3 View
We need an artefact-free preparation of AA2024-T3 for EBSD investigations? Does anybody have recommendations?
08 August 2018 7,762 14 View
Roaldite is a mineral phase (possibly) described in steel but (rarely) discovered in iron meteorites. The structure looks like fcc iron containing in the center an N atom. Is there anything known...
08 August 2018 6,627 7 View
The backscattering of electrons obviously happens with the core of the atoms or ions. If it is related to the mass I would expect an impact of protons and neutrons. If it is an impact of the...
08 August 2018 3,323 7 View
Already in 1927 Seljakow, Kurdjumow and Goodtzow discussed the observed broadening of martensite peaks by 4 different reason: a) grain size, b) concentration variation in solid solution, c)...
07 July 2018 1,855 14 View
The pseudocubic martensite (Fe-C alloy) is typically described as tetragonal phase. Why space group type P 42/n (IT-Nr. 86) is used? I 4/mmm would generate the same atomic arrangement, and also...
07 July 2018 7,673 9 View
Recently we observed an effect we cannot explain. Investigating a sample in transmission electron microscope (TEM) which contains mainly C, O, F, and a bit Bi, also the Cu grid delivers a...
03 March 2018 9,043 29 View
CBED (convergent beam electron diffraction) is known as one of the most sensitive techniques for local lattice parameter determination using electrons. I have no doubts regarding the precision of...
02 February 2018 6,445 3 View
We've just analysed a microstructure of a cubic closed-packed (fcc) material. As visible from the color-coded IPF map (Y parallel to the long axis of the grains) the aspect ratio of the grains is...
01 January 2018 2,175 42 View
We recently discovered a phase transformation during a careful metallographic EBSD preparation. Does anyone recongnized this, or does this effect has been reported already somewhere? The material...
01 January 2018 8,008 18 View
Miller's indexing of lattice planes defines that lattice planes are described by integer values of h, k and l which are prime to each other. From this follows that lattice planes like (002) are...
12 December 2017 9,190 9 View
For the calculation of uncorrelated misorientations Mackenzie introduced nearly 60 years ago the theoretical misorientation-angle distribution (Mackenzie plots) in case of no texture, i.e. for a...
12 December 2017 4,903 0 View
Hough transformation for an automated band detection in electron backscatter diffraction (EBSD) patterns is a commonly used. As two-dimensional coordinates the tilt and the distance from a...
12 December 2017 9,407 8 View
For the difference between crystal orientations sometimes the term misorientation but also the term disorientation is used. Is there any difference, or are these terms describing the same phenomenon?
12 December 2017 9,659 11 View
We are often talking about martensite, however, martensite is as far as I know never listed as phase in a database like ICSD. Asking metal physists they told me many years ago that martensite is a...
12 December 2017 5,175 16 View
I am a bit confused about the definition of the terms packet, block (or even sub-block), lath, subgrain used for the description of the microstructure of martensite after transformation from...
11 November 2017 3,092 46 View
Electron backscatter diffraction (EBSD) is a very surface sensitive technique which requires a very careful surface preparation. When do you start to believe, your surface preparation is...
11 November 2017 4,802 18 View
Until now I did not work with the map component of Tango (Channel5, Oxford Instr.). Therefore a short question: attached are two images displaying the recrystallized fraction of a martensitic...
11 November 2017 4,943 2 View
We all know that we can describe crystal lattices by the 14 Bravais lattice types. Many calculations or explanations are, however, related to the primitive lattices. The most prominent impact of...
09 September 2017 3,826 0 View
As far as I understood the concept of packing, a cubic or hexagonal closed-packed (ccp or hcp) arrangement of atoms as in austenite (gamma-Fe), Ni, Cu etc represents the most dense packing of...
11 November 2016 3,427 16 View
The term pseudosymmetry in crystallography is used if a higher symmetry appears or is experimentally observed. This is a probably wide field if one considers that there are many different kinds of...
09 September 2016 9,731 20 View
I am looking for the structure data of hexagonal AlTi2 and tetragonal phase Ti3Al5. The latter is described in space group P 4/mbm and should have lattice parameters of about a=11.43A and c=4.04A....
09 September 2016 1,547 10 View
Parallel planes in reciprocal lattice can be easily distinguished by terms like ZOLZ (zero order Laue zone), FOLZ (first order Laue zone) etc. Is there any therm which is equivalent in crystal...
08 August 2016 8,980 5 View
It is well known that pyrite shows striations along . Although cubic but according to the point group symmetry m-3 the striation is commonly only visible along one of the on...
08 August 2016 2,395 17 View
Electron backscatter diffraction (EBSD) is commonly discussed as diffraction phenomenon. In one of his last contributions, one of the fathers of EBSD, Oliver C. Wells, pointed out in 2012: EBSP is...
07 July 2016 8,280 0 View
Crystal structures consisting of stacked layers can be described by Ramsdell notation. Thus, cubic-closed packed (ccp) is given by a sequence ABC....or 3C, whereas hcp (hexagonal-closed packed) is...
07 July 2016 2,036 7 View
We recently discussed problems related to lattice parameter determination with EBSD and the missing accuracy in comparison to other techniques, especially XRD. I pointed out that many phases, e.g....
04 April 2016 1,968 12 View
How reliable is a determination of lattice parameters using a single electron backscatter diffraction pattern? Who determines lattice parameters in order to discover/identify a local phase, e.g....
04 April 2016 1,463 11 View
The space group symmetry of the feldspar mineral albite is (typically) described in databases by the Hermann-Mauguin symbol C-1, although a view in the International Tables for Crystallography...
03 March 2016 10,016 23 View
Investigating different iron meteorites I found recently a {011} pole figure which shows the pole distribution in the attached image. It represents the orientations found for the bcc phase...
02 February 2016 3,394 3 View
Usually a translation lattice is invariant, i.e. one can describe it by different basis vectors, primitive or centered etc., but the arrangement of the lattice points won't change at all, only...
11 November 2015 4,700 8 View
Especially for long term investigations like element or orientation mapping in scanning electron microscopy a clean sample is required in order to prevent drift. Often plasma-cleaning is...
11 November 2015 4,751 11 View
Typically we distinguish between 6 translation lattices, 7 crystal systems and 14 Bravais lattices. How trustful a phase separation by EBSD can be? Is it possible to say, phases with an F-lattice...
11 November 2015 5,050 1 View
For many years I am using an SEM (scanning electron microscope) with variable pressure (i.e. low vacuum) which dramatically helps if any kind of charging occurs. Often only a very small chamber...
11 November 2015 2,765 4 View
Energy dispersive and wave length dispersive X-ray spectroscopy are complementary techniques where the first is quite fast and (theoretically) enables the observation of all elements...
10 October 2015 4,718 22 View
Also nowadays where everything will be zoomed during printing the magnification is given, although this does not match to the often also given scale bar. Is this still acceptable, or shouldn't...
09 September 2015 9,586 35 View
New analytical systems are assumed to be very user-friendly and "calibration-free". What are your experiences? Is there any relationship to the effective size of the EDS detector?
09 September 2015 5,912 0 View
Over the last few weeks I tried to derive the lattice parameters using electron backscatter diffraction (EBSD) in SEM. Comparable investigations using simulated patterns gave in promising results....
09 September 2015 10,088 8 View
There are several proof now that the TKD (Transmission Kikuchi Diffraction) signal is formed at the lower surface of the sample. How big is the fraction of electrons which pass the sample without...
09 September 2015 5,264 4 View
The increasing gnomonic distortion in TKD patterns is obviously a problem which is not to be underestimated. The results are misindexings caused by wide bands which preferably appear for phases...
09 September 2015 6,799 13 View
It is widely know that physically a short beam size means better resolution because of the bean spread. This is a major argument for TKD (transmission Kikuchi diffraction) in SEM , however it was...
09 September 2015 2,294 9 View
Does anyone characterize non-cubic SiC-polytypes by EBSD? How would you define the necessary requirements?
05 May 2015 3,443 8 View
EBSD patterns are usually assumed to have a quite low accuracy regarding the lattice parameter determination. What are the typical limits and which parameters are important? Up to which resolution...
05 May 2015 2,710 9 View
For the calculation of the wavelength of electrons the acceleration voltage applied at the SEM (scanning electron microscope) is required. How big is the error of this value? Is there any...
05 May 2015 1,758 7 View
If I have an arrangement of (incomplete) lattice points which are slightly shifted against each other. When does a 3D Fourier analysis give acceptable values of the periodicity in 3D? How many...
05 May 2015 3,389 2 View
Did anybody investigated agate and observed radiation damages caused by electrons? Attached is one image which displays a forescattered elevtron image. It displays clearly orientation contrast in...
04 April 2015 8,747 23 View
For crystalline materials containing more than one phase, e.g. for mineralogical samples but also for some technical products like steel or Ti-Al, is it meaningful to display the microstructure by...
02 February 2015 6,360 9 View
Crystal orientation maps, e.g. derived by EBSD, are often displayed in so-called inverse pole figure (IPF) coloring. Do these maps (often three maps are displayed for reference direction X, Y and...
02 February 2015 7,071 13 View
Because of the superimposition of multiple orders of interferences, but also because each band is affected by any other band since each lattice plane is intersected by all other planes, the...
01 January 2015 1,192 9 View
The indexing of EBSD patterns is a quite secret business. It is clear that the band detection is done by Hough or Radon transform. It is known that the indexing uses the angles between planes...
12 December 2014 6,794 8 View
Are different kinds of HOLZ rings thinkable?
12 December 2014 9,357 2 View
As far as I know, two groups spend some time to investigate and determine lattice parameters in EBSD patterns using HOLZ rings. The first is the group around J.R. Michael from Sandia Lab. (USA)...
12 December 2014 6,265 1 View
If one deals with several phases of the same crystal metric, especially cubic phases, wouldn't it be beneficial to use the band intensities as additional criterion during indexing?
12 December 2014 5,267 10 View
Is the number of possible angles between symmetry-equivalent lattice planes {hkl} predictable, or do I have to generate them all and calculate the angles for each pair? I assume it is a property...
12 December 2014 8,175 19 View
It is clear that this is done because of the enormous incease of speed, but how big would be the advantage using grey scale images? How much time it would take if speed wouldn't be the only rule?...
12 December 2014 3,943 2 View
There is a strong believe that 15keV delivers the best compromise regarding diffraction signal and resolution, but I guess this is only correct for a very specific situation, e.g. discussed in the...
12 December 2014 7,979 6 View
Following the advertizing statements of several manufacturers there are several benefits using square-shaped phosphor-screens for EBSD pattern detection. Any truth to the rumour? Or is the used...
11 November 2014 7,931 6 View
What is the (real) reason for the 70 degrees tilt of samples used for EBSD investigations?
11 November 2014 2,926 9 View
Is there any proof that the tilt improves the signal, or does it only affects the pattern center positioning since the working distance can be increased so that the gnomonic distortion are not...
11 November 2014 478 8 View
Since several years so-called fast EBSD detectors are available. They mainly deliver a higher speed because of a clearly smaller native image size of the used camera so that the read-out time and...
10 October 2014 6,967 18 View
Typically the precision (not accuracy) of EBSD measurements is assumed to be 0.5...2 degrees which is certainly a very rough description since it depends on many factors like pattern and Hough...
10 October 2014 6,478 18 View
Often EBSD maps are performed using "integer values" like 50nm for step width (or pixel dimension) instead of 53nm. Is there any meaningful reason why one has to do this or is this simply a matter...
10 October 2014 4,611 7 View
An essential problem interpreting EBSD patterns is the correct selection of phases, especially when they are not cubic so that the chosen phase affects the hit rate or the accuracy of the pattern...
10 October 2014 8,189 12 View
Which pattern center definition for electron backscatter diffraction (EBSD) do you prefere and why?
10 October 2014 9,905 9 View
In EBSD a common believe exists which claims that cubic phases are easier to index than phases of lower symmetry. Since only the (pre calculated) interplanar angles are used - except of the...
10 October 2014 8,328 6 View
Electron backscatter diffraction (EBSD) in SEM is a powerful technique. Unfortunately it has the reputation to be difficult in use and interpretation. Moreover, obviously several limitations or...
09 September 2014 4,544 4 View
It is currently believed that EBSD as a diffraction technique cannot distinguish between polar directions although Baba-Kishi showed the opposite already 20 years ago. Which materials and...
09 September 2014 2,397 1 View
Caused by the high sample tilt required for EBSD measurements, the intensity profiles of bands become asymmetric. Horizontal bands are fully affected whereas vertical bands are practically not...
09 September 2014 3,241 5 View
Everybody knows that EBSD already has a lot of problems which are related to drift phenomena. This becomes unpredictable at higher magnification which are typical in combination with FIB...
08 August 2014 304 2 View
Since for Transmission Kikuchi Diffraction (TKD) in SEM a TEM sample is required, where are the advantages of TKD? If somebody has the opportunity to produce TEM samples he/she should also has a...
08 August 2014 1,154 10 View
For band detection in EBSD (Kikuchi) patterns the Hough transform is used which is applied on binary images exclusively (in commercial software for maximum speed). If one would apply the Hough...
08 August 2014 5,388 2 View
We measured a microstructure of hydrothermal Au by EBSD and EDS which contains locally a small amount of Ag. The pure gold areas are not separated as grains but obviously linked to large angle...
08 August 2014 2,332 7 View
Faster measurements are a very understandable desire. Especially in analytics applied in scanning electron microscopy mainly two opportunities exist: increase of the source intensity (beam...
08 August 2014 6,334 7 View
A (materials) phase is defined by either a unique structure and/or chemical composition. When phases are very similar (e.g. doping, solid solution), when do we start to talk about different...
07 July 2014 9,164 20 View
Are there additional factors beside of general and special reflection conditions which may cause the absence of a reflection, e.g. the occupation factor of a position, or the substitution by...
07 July 2014 7,254 20 View
For metric investigations of microstructures drift is a serious problem. As one possible reason the generation of contamination during the slow scan is assumed and often discussed. How do you try...
06 June 2014 1,892 16 View
Electron beam diameter, spot size, and pixel size of the image are typical parameter to describe the the scanning behaviour of an SEM. Investigating small-grain microstructures like martensite at...
06 June 2014 9,769 2 View
The determination of an average grain size or a grain size distribution is an often used tool applied on EBSD measurements. I wonder how accurate the result can be if one considers the practically...
06 June 2014 7,814 5 View
For high-resolving (angular) interpretations of EBSD patterns, e.g. for GND analysis or the characterisation of the microstructure of pseudo-symmetric phases (photovoltaic phases like I-III-VI...
06 June 2014 1,156 5 View
Although martensite is described as phase containing a small amount of carbon, in databases it is not listed as a specific phase. Like bainite it is described as microstructure and not as phase....
05 May 2014 343 28 View
Despite missing knowledge about intensities of reflectors, dynamical diffraction effects, superimposition of higher order reflections, and low accuracy in bandwidth determination, how reliable is...
05 May 2014 548 2 View
For EBSD measurements surfaces are usually investigated at high tilt angles, typically 70 degrees. However, at low magnifications (< x200) an ideally rectangular scanned ares degenereates into a...
05 May 2014 9,848 4 View
For investigations of EBSD patterns I need tellurium crystals. Unfortunately, the only material I could get is tellurium powder. Is there anybody who has experience with melting of (toxic) tellurium?
05 May 2014 6,206 8 View
Local phase identification in scanning electron microscopy would be a wonderful tool if electron backscatter diffraction (EBSD) would be more sensitive regarding lattice parameters. In uncertain...
05 May 2014 7,974 4 View
In texture analysis the data are often symmetrized in order to increase the statistical significance assuming an expected symmetry. To this aim terms like triclinic, monoclinic and orthorhombic...
05 May 2014 10,130 3 View
Does anybody know a phase which crystallizes in the same trigonal point group but in space groups with different alignments of the symmetry elements, e.g. in 312 or 321, or 3m1 or 31m, 3c1 or 31c...
05 May 2014 4,466 4 View
Point group 32 is obviously a merging of two different groups 321 and 312 since for both setups space groups exist which cannot be transferred into each other. For the first the basis vector a is...
05 May 2014 4,845 0 View
Except of polarization direction.
05 May 2014 8,026 10 View
Is it really common to substitute "i" and "t" by a dot, i.e. instead of (hkil) and [uvtw] in crystallographic journals (hk.l) and [uv.w] are preferred? Is this the only advantage that h,k,i...
04 April 2014 746 6 View
Recently, I submitted a paper in a crystallographic journal where I used Miller-Bravais indices (hkil) for lattice planes, and Weber (Schweizer) symbols [uvtw] for lattice directions. One reviewer...
04 April 2014 498 5 View
Originally Rietveld introduced the pattern refinement for crystal structure determination using powder diffraction data. It still took nearly 20 years until the least-square approach has been...
03 March 2014 5,927 19 View
If magnetite and hematite transform into each other they keep the close-packed O framework and obviously use partial dislocation movement to change between hexagonal and cubic stacking sequence....
12 December 2013 1,530 1 View
The availability of technical equipment simplifies our live, and thus, also teaching. However, I have the impression that it seduces to show to much information and, moreover, since most of...
01 January 1970 7,272 35 View
15 years after the introduction of CCD-based EBSD detectors a new camera technology enters the EBSD world. It is hard to believe, the formerly demonised CMOS chips are now the saviours of the EBSD...
01 January 1970 4,993 5 View
It is well-accepted that martensite is tetragonally distorted with respect to bcc. I wonder, whether anyone published already EBSD maps based on a tetragonal indexing? Or does everybody simply...
01 January 1970 1,273 17 View
