Sample Preparation for TEM analysis (Bulk metal, Powder sample, Brittle material)

POWDER SAMPLE:

  1. Mill the powder sample into very fine size (orders of nm)
  2. Suspend the powders in ethanol (alcohol medium)
  3. Ultrasonicate to disperse the powder till a clear solution is obtained
  4. Using a dropper, dispense few drops of suspension onto the carbon coated copper grid.
  5. Please the grid on TEM sample holder for observation.

    BULK SAMPLE:

  6. Take the bulk sample, and slice it into thickness of < 100 µm
  7. Punch a 3 mm disc from the sheet
  8. Use dimple grinder (either one side or both sides) to bring it down to thickness of 2-5 µm
  9. Use electrochemical etching for getting a perforation on the sample
  10. Follow it up (optional, or in place of electrochemical etching) with ion-beam milling.
  11. The entire sample can now be placed on TEM holder (and will not require a grid for support).

BRITTLE SAMPLE:

  1. Crush the brittle material and follow the powder process. Here a copper grid (with or without carbon coating) will be needed.
  2. For observing bulk sample, the grinding of the sample should be done to bring it down to < 100 µm thickness.
  3. Now punch the 3 mm disc from the sheet.
  4. Use dimple grinder for thinning it down to 2-5 µm.
  5. Use ion-beam milling process for getting a thin region (electron transparent) for observation under TEM. The entire sample can be used stand alone (without any support grid) for imaging.