Story

Removal of Surface Layers - Sample Preparation for SEM and TEM

Application Note for Leica EM RES102 - Material Research, Industrial Manufacturing, Natural Resources

Sometimes it is necessary to remove surface layers to gain access to the real surface structure. That can be a native oxide, or layers coming from the preparation process itself, like re-deposition. Depending on the layers thickness and the energy used for the cleaning process, it takes between a few seconds and half an hour. The energy depends on the milling rate of the material.

Application Examples shown here:
Reducing the thickness of a Pt Coating
Removing re-deposition from a TEM sample surface

Authors

Topics & Tags

Reducing the Thickness of a Pt Coating

Purpose
The coating of the oil shale sample shown in the images below was too thick (Fig.1) The sample looks "foggy".
The real structure is not clearly visible.
A short los energy milling solved the problem.

Preparation conditions

Acceleration voltage: 2 kV
Gun current:1.5 mA
Milling time:2 min


Result
After milling the oils shale structure is clearly visible (Fig.2).

Cleaning of a Contaminated TEM Sample

Purpose
The reason for contamination of TEM samples glued on a Cu ring was single sided ion milling. Because the rear side can have material re-deposited from the Cu ring (Fig.3)

Preparation Parameters

Acceleration voltage:2 kV
Gun current:1.5 mA
Sample movement:Rotation
Milling angle:10°
Milling time:25 min.

Results
As shown in the image the re-deposition is completely removed after the cleaning procedure. The grain structure is clearly visible (Fig.4).

Interested to know more?

Talk to our experts. We are happy to answer all your questions and concerns.

Contact Us

Do you prefer personal consulting?

  • Leica Microsystems Inc.
    1700 Leider Lane
    Buffalo Grove, IL 60089 United States
    Office Phone : +1 800 248 0123
    Service Phone : 1 800 248 0223
    Fax : +1 847-236-3009

You will find a more detailed list of local contacts here.