CBEDDarkField

Index

CBED Dark Field

These tool buttons are used to set the LACBED Dark Field conditions:

Open the Apertures window.
Open the Specimen window.

LACBED dark field patterns are calculated by:

Selecting a diffracted disk using the Apertures window, centering the LACBED aperture and tilting the illumination on the disk (Figures 1a, 1b).
Setting a large enough beam convergence (Fig. 1c) and selecting the LACBED and Shift checkboxes. (Fig. 1d).


Figure 1a (2, -2, 0) on optical axis CLC=(000).	Figure 1b LACBED aperture at (2,-2, 0) CLC=(000).

Figure 1c Beam convergence.	Figure 1d LACBED options.

Figures 2a, 2b show such a Dark Field LACBED disk for Si [1,1,3], 300kV, (2,-2,0).


Figure 2a (2,-2,0) ZOLZ lines CLC=(000).	Figure 2b (2,-2,0) Dark Field disk CLC=(000).

Using the Specimen settings window, activated with sample , one can set the (2,-2,0) reflection at exact Bragg condition, i.e. set the center of the Laue circle at (1,-1,0) as shown in Figures 3a, 3b.


Figure 3a (2,-2,0) ZOLZ lines CLC=(1,-1,0).	Figure 3b (2,-2,0) Dark Field disk CLC=(1,-1,0).