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Warning |
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Do not attempt to do anything you have not been trained to do by ePSIC staff. |
In order to run the COSMO corrector the sample must have areas of thin amorphous material. Any lattice in the image may interfere with the aberration calculation.
Info |
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If sample contaminates significantly the aberration correction may fail. If possible beam shower the sample. |
- Ensure that the objective lens is set to standard defocus and microscope at x800k or greater.
- Increase the height of the sample so that the image is under focus (rings get smaller as you move sample -z) and numerous thon rings can be observed.
- Stop the view on Digital Micrograph and press monitor on the COSMO TEM auto-adjust software.
- Using COSMO software correct 2 fold astigmatism (A2) to ≤5nm.
Using the z-piezo drive set defocus to about -200nm.
Info When super-fine is selected on the trackball goniometer control, the diff focus dial on the right hand panel controls the z-piezo drive.
Set the tableaux angle to the required level (recommended to start at ~20 mrad) and run a tableaux.
Correct for higher order aberrations.
Iterate 4-7 as required.
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