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 preparation. If already in 2D the predicted beam position is quite unreliable and can be several steps away from the assumed position, how reliable is a beam position in 3D which presupposes an ideal (constant) ablation rate of the FIB preparation? How accurate the crystallographic description of grain or phase boundaries can be?
I think the alignment of the apertures could cause some Trouble. If the beam of FIB column are not perfectly aligned with the SEM on one Hand drifts are occuring very often. Or second the FIB apertures have to be realigned. Which machine are you using? I could also assume that your FIBxy correction Parameters are not perfectly aligned.
Hi Eric, your remarks only concern the third dimension and certainly shows how problematic a collection of a 3D dataset is, despite the effort of a careful alignment after each ablation by image cross correlation. But even if you would be able to have an exact ablation in z (what I hardly disbelieve if you consider the effect of 70 degree tilt which gains any deviation from the ideal value by a factor of about three) the uncertainties of (unknown) local charging and perhaps (unknown) magnetic effects in your sample caused by single phases results in distortions in 2D EBSD scans which differs from layer to layer so that a simple stacking of the layers can give only "roughly" an impression of the micro (or better: nano) structure. There is nearly no 3D data set where all layers havn't to be realigned in order to minimize "obvious" deviations, and as far as I know there are standardly only translations in x and y possible. Voxel related algorithms are still the exception, and the restrains you have to define for the "best correction" already implement some information one actually wants to get from 3D datasets.
- Badges
- Science topic
- Similar topics
- Computer Science and Engineering
- Computer Graphics and Animation
- 3D