LabAdviser/314/Microscopy 314-307/FIB/Helios/Quick check list for EBSD measurement

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This section is written by Alice Bastos da Silva Fanta @DTU Nanolab

Quick check list for starting EBSD on the Helios

1. Attach the sample to the holder

• don´t use carbon tape
• when using silver paint, wait until paint is completely dry
• Interesting surface should be parallel to the 54?tilt side of the holder.

2. When you have an image of your sample inside the microscope. Focus and link the focus (link Z to FWD). The correct WD will be shown on the Z coordinate table of the Stage page.

• EBSD optimal WD is 8mm, (can be varied between 4-13mm)
• If you are measuring in the middle of your sample make sure the top edge is not too close to the pole piece.

3. Align the top edge of your sample or pre-tilt holder to the horizontal direction using XT Align Feature in the drop-down menu Stage.

4. In case needed rotate the stage 180? to face the EBSD camera

5. Tilt your stage to 16? (or if you are using another holder tilt to have your sample at 70? tilt)

6. Focus you sample well. (Use already an appropriated beam current and voltage for EBSD.)

• Use dynamic focus in case needed
• Only tilt correct your image for pictures, never tilt correct your image during an EBSD map

7. Open OIM data collection software

8. When everything is settle, insert the EBSD detector Always make sure it is safe to insert the EBSD detector!

9. Check if SEM image needs readjustments (contrast, brightness, focus)

10. Pause the optical video image of the chamber

11. In OIM go to the Phase page and load the material files

• You may create a material file or change something in the existing one, but ALWAYS save with a new name. NEVER OVERWRITE EXISTING FILES!

12. Set up your camera parameters: a. Microscope: use a fast scan at low resolution b. OIM software: Adjust binning, exposure time and gain ( <10) (remember, always when you change the binning the background is automatic collected, uncheck it!) c. Collect the background (make sure it does not contain any pattern!) d. If you want you may modify your image, as for example using (Normalize Intensity Histogram)

13. If needed change beam current/ voltage/ sample area and repeat step 11. Use the toggle Beam Control to switch the beam control between OIM and Helios

14. Increase the magnification to the desired one

15. Capture an image (in the interactive page) and check the patterns on your sample. 16. Check that the WD in the microscope and OIM software is the same.

17. Set up the Hough transform (look if it is working fine specially in “bad” patterns)

18. Check indexing in the indexing page

19. When everything is correct go to the Scan page and choose the area to be mapped a. You may choose if you want to have an SEM or an FSD image. b. You may also choose the image resolution (on the OIM software) and if this should to be tilt corrected or not.(this can be done under the dropdown menu Settings/Beam Control Settings)

20. If you have changed anything in the image. Capture the image again.

21. Set map area and parameters a. Set folder and file name b. Choose options for recording data types. c. Set step size d. Remember to use the information dialog to write some map parameters! e. Press OK

22. More scans can be set up by drawing additional areas in the same field of view.

23. If you doing a long overnight measurement go to Setting in the menu bar and tick ENABLE AUTO HT OFF.

24. Once everything is set. Click start scan or start batch ( in case of several maps)

25. Remember to always take in consideration when setting up you EBSD scan what kind of data you expect to get and adjust the microscope, camera, Hough and map parameters to adapt the requirements. You can find further information on this subject in a folder called EBSD (which should be inside the Helios room), and in a literature collection (to be done!!!!!) or contact a person responsible for EBSD at CEN.